+++ /dev/null
----
-title: CommonMark Spec
-author: John MacFarlane
-version: 0.25
-date: '2016-03-24'
-license: '[CC-BY-SA 4.0](http://creativecommons.org/licenses/by-sa/4.0/)'
-...
-
-# Introduction
-
-## What is Markdown?
-
-Markdown is a plain text format for writing structured documents,
-based on conventions used for indicating formatting in email and
-usenet posts. It was developed in 2004 by John Gruber, who wrote
-the first Markdown-to-HTML converter in perl, and it soon became
-widely used in websites. By 2014 there were dozens of
-implementations in many languages. Some of them extended basic
-Markdown syntax with conventions for footnotes, definition lists,
-tables, and other constructs, and some allowed output not just in
-HTML but in LaTeX and many other formats.
-
-## Why is a spec needed?
-
-John Gruber's [canonical description of Markdown's
-syntax](http://daringfireball.net/projects/markdown/syntax)
-does not specify the syntax unambiguously. Here are some examples of
-questions it does not answer:
-
-1. How much indentation is needed for a sublist? The spec says that
- continuation paragraphs need to be indented four spaces, but is
- not fully explicit about sublists. It is natural to think that
- they, too, must be indented four spaces, but `Markdown.pl` does
- not require that. This is hardly a "corner case," and divergences
- between implementations on this issue often lead to surprises for
- users in real documents. (See [this comment by John
- Gruber](http://article.gmane.org/gmane.text.markdown.general/1997).)
-
-2. Is a blank line needed before a block quote or heading?
- Most implementations do not require the blank line. However,
- this can lead to unexpected results in hard-wrapped text, and
- also to ambiguities in parsing (note that some implementations
- put the heading inside the blockquote, while others do not).
- (John Gruber has also spoken [in favor of requiring the blank
- lines](http://article.gmane.org/gmane.text.markdown.general/2146).)
-
-3. Is a blank line needed before an indented code block?
- (`Markdown.pl` requires it, but this is not mentioned in the
- documentation, and some implementations do not require it.)
-
- ``` markdown
- paragraph
- code?
- ```
-
-4. What is the exact rule for determining when list items get
- wrapped in `<p>` tags? Can a list be partially "loose" and partially
- "tight"? What should we do with a list like this?
-
- ``` markdown
- 1. one
-
- 2. two
- 3. three
- ```
-
- Or this?
-
- ``` markdown
- 1. one
- - a
-
- - b
- 2. two
- ```
-
- (There are some relevant comments by John Gruber
- [here](http://article.gmane.org/gmane.text.markdown.general/2554).)
-
-5. Can list markers be indented? Can ordered list markers be right-aligned?
-
- ``` markdown
- 8. item 1
- 9. item 2
- 10. item 2a
- ```
-
-6. Is this one list with a thematic break in its second item,
- or two lists separated by a thematic break?
-
- ``` markdown
- * a
- * * * * *
- * b
- ```
-
-7. When list markers change from numbers to bullets, do we have
- two lists or one? (The Markdown syntax description suggests two,
- but the perl scripts and many other implementations produce one.)
-
- ``` markdown
- 1. fee
- 2. fie
- - foe
- - fum
- ```
-
-8. What are the precedence rules for the markers of inline structure?
- For example, is the following a valid link, or does the code span
- take precedence ?
-
- ``` markdown
- [a backtick (`)](/url) and [another backtick (`)](/url).
- ```
-
-9. What are the precedence rules for markers of emphasis and strong
- emphasis? For example, how should the following be parsed?
-
- ``` markdown
- *foo *bar* baz*
- ```
-
-10. What are the precedence rules between block-level and inline-level
- structure? For example, how should the following be parsed?
-
- ``` markdown
- - `a long code span can contain a hyphen like this
- - and it can screw things up`
- ```
-
-11. Can list items include section headings? (`Markdown.pl` does not
- allow this, but does allow blockquotes to include headings.)
-
- ``` markdown
- - # Heading
- ```
-
-12. Can list items be empty?
-
- ``` markdown
- * a
- *
- * b
- ```
-
-13. Can link references be defined inside block quotes or list items?
-
- ``` markdown
- > Blockquote [foo].
- >
- > [foo]: /url
- ```
-
-14. If there are multiple definitions for the same reference, which takes
- precedence?
-
- ``` markdown
- [foo]: /url1
- [foo]: /url2
-
- [foo][]
- ```
-
-In the absence of a spec, early implementers consulted `Markdown.pl`
-to resolve these ambiguities. But `Markdown.pl` was quite buggy, and
-gave manifestly bad results in many cases, so it was not a
-satisfactory replacement for a spec.
-
-Because there is no unambiguous spec, implementations have diverged
-considerably. As a result, users are often surprised to find that
-a document that renders one way on one system (say, a github wiki)
-renders differently on another (say, converting to docbook using
-pandoc). To make matters worse, because nothing in Markdown counts
-as a "syntax error," the divergence often isn't discovered right away.
-
-## About this document
-
-This document attempts to specify Markdown syntax unambiguously.
-It contains many examples with side-by-side Markdown and
-HTML. These are intended to double as conformance tests. An
-accompanying script `spec_tests.py` can be used to run the tests
-against any Markdown program:
-
- python test/spec_tests.py --spec spec.txt --program PROGRAM
-
-Since this document describes how Markdown is to be parsed into
-an abstract syntax tree, it would have made sense to use an abstract
-representation of the syntax tree instead of HTML. But HTML is capable
-of representing the structural distinctions we need to make, and the
-choice of HTML for the tests makes it possible to run the tests against
-an implementation without writing an abstract syntax tree renderer.
-
-This document is generated from a text file, `spec.txt`, written
-in Markdown with a small extension for the side-by-side tests.
-The script `tools/makespec.py` can be used to convert `spec.txt` into
-HTML or CommonMark (which can then be converted into other formats).
-
-In the examples, the `→` character is used to represent tabs.
-
-# Preliminaries
-
-## Characters and lines
-
-Any sequence of [characters] is a valid CommonMark
-document.
-
-A [character](@) is a Unicode code point. Although some
-code points (for example, combining accents) do not correspond to
-characters in an intuitive sense, all code points count as characters
-for purposes of this spec.
-
-This spec does not specify an encoding; it thinks of lines as composed
-of [characters] rather than bytes. A conforming parser may be limited
-to a certain encoding.
-
-A [line](@) is a sequence of zero or more [characters]
-other than newline (`U+000A`) or carriage return (`U+000D`),
-followed by a [line ending] or by the end of file.
-
-A [line ending](@) is a newline (`U+000A`), a carriage return
-(`U+000D`) not followed by a newline, or a carriage return and a
-following newline.
-
-A line containing no characters, or a line containing only spaces
-(`U+0020`) or tabs (`U+0009`), is called a [blank line](@).
-
-The following definitions of character classes will be used in this spec:
-
-A [whitespace character](@) is a space
-(`U+0020`), tab (`U+0009`), newline (`U+000A`), line tabulation (`U+000B`),
-form feed (`U+000C`), or carriage return (`U+000D`).
-
-[Whitespace](@) is a sequence of one or more [whitespace
-characters].
-
-A [Unicode whitespace character](@) is
-any code point in the Unicode `Zs` class, or a tab (`U+0009`),
-carriage return (`U+000D`), newline (`U+000A`), or form feed
-(`U+000C`).
-
-[Unicode whitespace](@) is a sequence of one
-or more [Unicode whitespace characters].
-
-A [space](@) is `U+0020`.
-
-A [non-whitespace character](@) is any character
-that is not a [whitespace character].
-
-An [ASCII punctuation character](@)
-is `!`, `"`, `#`, `$`, `%`, `&`, `'`, `(`, `)`,
-`*`, `+`, `,`, `-`, `.`, `/`, `:`, `;`, `<`, `=`, `>`, `?`, `@`,
-`[`, `\`, `]`, `^`, `_`, `` ` ``, `{`, `|`, `}`, or `~`.
-
-A [punctuation character](@) is an [ASCII
-punctuation character] or anything in
-the Unicode classes `Pc`, `Pd`, `Pe`, `Pf`, `Pi`, `Po`, or `Ps`.
-
-## Tabs
-
-Tabs in lines are not expanded to [spaces]. However,
-in contexts where indentation is significant for the
-document's structure, tabs behave as if they were replaced
-by spaces with a tab stop of 4 characters.
-
-```````````````````````````````` example
-→foo→baz→→bim
-.
-<pre><code>foo→baz→→bim
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
- →foo→baz→→bim
-.
-<pre><code>foo→baz→→bim
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
- a→a
- ὐ→a
-.
-<pre><code>a→a
-ὐ→a
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
- - foo
-
-→bar
-.
-<ul>
-<li>
-<p>foo</p>
-<p>bar</p>
-</li>
-</ul>
-````````````````````````````````
-
-```````````````````````````````` example
-- foo
-
-→→bar
-.
-<ul>
-<li>
-<p>foo</p>
-<pre><code> bar
-</code></pre>
-</li>
-</ul>
-````````````````````````````````
-
-```````````````````````````````` example
->→→foo
-.
-<blockquote>
-<pre><code> foo
-</code></pre>
-</blockquote>
-````````````````````````````````
-
-```````````````````````````````` example
--→→foo
-.
-<ul>
-<li>
-<pre><code> foo
-</code></pre>
-</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
- foo
-→bar
-.
-<pre><code>foo
-bar
-</code></pre>
-````````````````````````````````
-
-```````````````````````````````` example
- - foo
- - bar
-→ - baz
-.
-<ul>
-<li>foo
-<ul>
-<li>bar
-<ul>
-<li>baz</li>
-</ul>
-</li>
-</ul>
-</li>
-</ul>
-````````````````````````````````
-
-
-
-## Insecure characters
-
-For security reasons, the Unicode character `U+0000` must be replaced
-with the REPLACEMENT CHARACTER (`U+FFFD`).
-
-# Blocks and inlines
-
-We can think of a document as a sequence of
-[blocks](@)---structural elements like paragraphs, block
-quotations, lists, headings, rules, and code blocks. Some blocks (like
-block quotes and list items) contain other blocks; others (like
-headings and paragraphs) contain [inline](@) content---text,
-links, emphasized text, images, code, and so on.
-
-## Precedence
-
-Indicators of block structure always take precedence over indicators
-of inline structure. So, for example, the following is a list with
-two items, not a list with one item containing a code span:
-
-```````````````````````````````` example
-- `one
-- two`
-.
-<ul>
-<li>`one</li>
-<li>two`</li>
-</ul>
-````````````````````````````````
-
-
-This means that parsing can proceed in two steps: first, the block
-structure of the document can be discerned; second, text lines inside
-paragraphs, headings, and other block constructs can be parsed for inline
-structure. The second step requires information about link reference
-definitions that will be available only at the end of the first
-step. Note that the first step requires processing lines in sequence,
-but the second can be parallelized, since the inline parsing of
-one block element does not affect the inline parsing of any other.
-
-## Container blocks and leaf blocks
-
-We can divide blocks into two types:
-[container block](@)s,
-which can contain other blocks, and [leaf block](@)s,
-which cannot.
-
-# Leaf blocks
-
-This section describes the different kinds of leaf block that make up a
-Markdown document.
-
-## Thematic breaks
-
-A line consisting of 0-3 spaces of indentation, followed by a sequence
-of three or more matching `-`, `_`, or `*` characters, each followed
-optionally by any number of spaces, forms a
-[thematic break](@).
-
-```````````````````````````````` example
-***
----
-___
-.
-<hr />
-<hr />
-<hr />
-````````````````````````````````
-
-
-Wrong characters:
-
-```````````````````````````````` example
-+++
-.
-<p>+++</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-===
-.
-<p>===</p>
-````````````````````````````````
-
-
-Not enough characters:
-
-```````````````````````````````` example
---
-**
-__
-.
-<p>--
-**
-__</p>
-````````````````````````````````
-
-
-One to three spaces indent are allowed:
-
-```````````````````````````````` example
- ***
- ***
- ***
-.
-<hr />
-<hr />
-<hr />
-````````````````````````````````
-
-
-Four spaces is too many:
-
-```````````````````````````````` example
- ***
-.
-<pre><code>***
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-Foo
- ***
-.
-<p>Foo
-***</p>
-````````````````````````````````
-
-
-More than three characters may be used:
-
-```````````````````````````````` example
-_____________________________________
-.
-<hr />
-````````````````````````````````
-
-
-Spaces are allowed between the characters:
-
-```````````````````````````````` example
- - - -
-.
-<hr />
-````````````````````````````````
-
-
-```````````````````````````````` example
- ** * ** * ** * **
-.
-<hr />
-````````````````````````````````
-
-
-```````````````````````````````` example
-- - - -
-.
-<hr />
-````````````````````````````````
-
-
-Spaces are allowed at the end:
-
-```````````````````````````````` example
-- - - -
-.
-<hr />
-````````````````````````````````
-
-
-However, no other characters may occur in the line:
-
-```````````````````````````````` example
-_ _ _ _ a
-
-a------
-
----a---
-.
-<p>_ _ _ _ a</p>
-<p>a------</p>
-<p>---a---</p>
-````````````````````````````````
-
-
-It is required that all of the [non-whitespace characters] be the same.
-So, this is not a thematic break:
-
-```````````````````````````````` example
- *-*
-.
-<p><em>-</em></p>
-````````````````````````````````
-
-
-Thematic breaks do not need blank lines before or after:
-
-```````````````````````````````` example
-- foo
-***
-- bar
-.
-<ul>
-<li>foo</li>
-</ul>
-<hr />
-<ul>
-<li>bar</li>
-</ul>
-````````````````````````````````
-
-
-Thematic breaks can interrupt a paragraph:
-
-```````````````````````````````` example
-Foo
-***
-bar
-.
-<p>Foo</p>
-<hr />
-<p>bar</p>
-````````````````````````````````
-
-
-If a line of dashes that meets the above conditions for being a
-thematic break could also be interpreted as the underline of a [setext
-heading], the interpretation as a
-[setext heading] takes precedence. Thus, for example,
-this is a setext heading, not a paragraph followed by a thematic break:
-
-```````````````````````````````` example
-Foo
----
-bar
-.
-<h2>Foo</h2>
-<p>bar</p>
-````````````````````````````````
-
-
-When both a thematic break and a list item are possible
-interpretations of a line, the thematic break takes precedence:
-
-```````````````````````````````` example
-* Foo
-* * *
-* Bar
-.
-<ul>
-<li>Foo</li>
-</ul>
-<hr />
-<ul>
-<li>Bar</li>
-</ul>
-````````````````````````````````
-
-
-If you want a thematic break in a list item, use a different bullet:
-
-```````````````````````````````` example
-- Foo
-- * * *
-.
-<ul>
-<li>Foo</li>
-<li>
-<hr />
-</li>
-</ul>
-````````````````````````````````
-
-
-## ATX headings
-
-An [ATX heading](@)
-consists of a string of characters, parsed as inline content, between an
-opening sequence of 1--6 unescaped `#` characters and an optional
-closing sequence of any number of unescaped `#` characters.
-The opening sequence of `#` characters must be followed by a
-[space] or by the end of line. The optional closing sequence of `#`s must be
-preceded by a [space] and may be followed by spaces only. The opening
-`#` character may be indented 0-3 spaces. The raw contents of the
-heading are stripped of leading and trailing spaces before being parsed
-as inline content. The heading level is equal to the number of `#`
-characters in the opening sequence.
-
-Simple headings:
-
-```````````````````````````````` example
-# foo
-## foo
-### foo
-#### foo
-##### foo
-###### foo
-.
-<h1>foo</h1>
-<h2>foo</h2>
-<h3>foo</h3>
-<h4>foo</h4>
-<h5>foo</h5>
-<h6>foo</h6>
-````````````````````````````````
-
-
-More than six `#` characters is not a heading:
-
-```````````````````````````````` example
-####### foo
-.
-<p>####### foo</p>
-````````````````````````````````
-
-
-At least one space is required between the `#` characters and the
-heading's contents, unless the heading is empty. Note that many
-implementations currently do not require the space. However, the
-space was required by the
-[original ATX implementation](http://www.aaronsw.com/2002/atx/atx.py),
-and it helps prevent things like the following from being parsed as
-headings:
-
-```````````````````````````````` example
-#5 bolt
-
-#hashtag
-.
-<p>#5 bolt</p>
-<p>#hashtag</p>
-````````````````````````````````
-
-
-A tab will not work:
-
-```````````````````````````````` example
-#→foo
-.
-<p>#→foo</p>
-````````````````````````````````
-
-
-This is not a heading, because the first `#` is escaped:
-
-```````````````````````````````` example
-\## foo
-.
-<p>## foo</p>
-````````````````````````````````
-
-
-Contents are parsed as inlines:
-
-```````````````````````````````` example
-# foo *bar* \*baz\*
-.
-<h1>foo <em>bar</em> *baz*</h1>
-````````````````````````````````
-
-
-Leading and trailing blanks are ignored in parsing inline content:
-
-```````````````````````````````` example
-# foo
-.
-<h1>foo</h1>
-````````````````````````````````
-
-
-One to three spaces indentation are allowed:
-
-```````````````````````````````` example
- ### foo
- ## foo
- # foo
-.
-<h3>foo</h3>
-<h2>foo</h2>
-<h1>foo</h1>
-````````````````````````````````
-
-
-Four spaces are too much:
-
-```````````````````````````````` example
- # foo
-.
-<pre><code># foo
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo
- # bar
-.
-<p>foo
-# bar</p>
-````````````````````````````````
-
-
-A closing sequence of `#` characters is optional:
-
-```````````````````````````````` example
-## foo ##
- ### bar ###
-.
-<h2>foo</h2>
-<h3>bar</h3>
-````````````````````````````````
-
-
-It need not be the same length as the opening sequence:
-
-```````````````````````````````` example
-# foo ##################################
-##### foo ##
-.
-<h1>foo</h1>
-<h5>foo</h5>
-````````````````````````````````
-
-
-Spaces are allowed after the closing sequence:
-
-```````````````````````````````` example
-### foo ###
-.
-<h3>foo</h3>
-````````````````````````````````
-
-
-A sequence of `#` characters with anything but [spaces] following it
-is not a closing sequence, but counts as part of the contents of the
-heading:
-
-```````````````````````````````` example
-### foo ### b
-.
-<h3>foo ### b</h3>
-````````````````````````````````
-
-
-The closing sequence must be preceded by a space:
-
-```````````````````````````````` example
-# foo#
-.
-<h1>foo#</h1>
-````````````````````````````````
-
-
-Backslash-escaped `#` characters do not count as part
-of the closing sequence:
-
-```````````````````````````````` example
-### foo \###
-## foo #\##
-# foo \#
-.
-<h3>foo ###</h3>
-<h2>foo ###</h2>
-<h1>foo #</h1>
-````````````````````````````````
-
-
-ATX headings need not be separated from surrounding content by blank
-lines, and they can interrupt paragraphs:
-
-```````````````````````````````` example
-****
-## foo
-****
-.
-<hr />
-<h2>foo</h2>
-<hr />
-````````````````````````````````
-
-
-```````````````````````````````` example
-Foo bar
-# baz
-Bar foo
-.
-<p>Foo bar</p>
-<h1>baz</h1>
-<p>Bar foo</p>
-````````````````````````````````
-
-
-ATX headings can be empty:
-
-```````````````````````````````` example
-##
-#
-### ###
-.
-<h2></h2>
-<h1></h1>
-<h3></h3>
-````````````````````````````````
-
-
-## Setext headings
-
-A [setext heading](@) consists of one or more
-lines of text, each containing at least one [non-whitespace
-character], with no more than 3 spaces indentation, followed by
-a [setext heading underline]. The lines of text must be such
-that, were they not followed by the setext heading underline,
-they would be interpreted as a paragraph: they cannot be
-interpretable as a [code fence], [ATX heading][ATX headings],
-[block quote][block quotes], [thematic break][thematic breaks],
-[list item][list items], or [HTML block][HTML blocks].
-
-A [setext heading underline](@) is a sequence of
-`=` characters or a sequence of `-` characters, with no more than 3
-spaces indentation and any number of trailing spaces. If a line
-containing a single `-` can be interpreted as an
-empty [list items], it should be interpreted this way
-and not as a [setext heading underline].
-
-The heading is a level 1 heading if `=` characters are used in
-the [setext heading underline], and a level 2 heading if `-`
-characters are used. The contents of the heading are the result
-of parsing the preceding lines of text as CommonMark inline
-content.
-
-In general, a setext heading need not be preceded or followed by a
-blank line. However, it cannot interrupt a paragraph, so when a
-setext heading comes after a paragraph, a blank line is needed between
-them.
-
-Simple examples:
-
-```````````````````````````````` example
-Foo *bar*
-=========
-
-Foo *bar*
----------
-.
-<h1>Foo <em>bar</em></h1>
-<h2>Foo <em>bar</em></h2>
-````````````````````````````````
-
-
-The content of the header may span more than one line:
-
-```````````````````````````````` example
-Foo *bar
-baz*
-====
-.
-<h1>Foo <em>bar
-baz</em></h1>
-````````````````````````````````
-
-
-The underlining can be any length:
-
-```````````````````````````````` example
-Foo
--------------------------
-
-Foo
-=
-.
-<h2>Foo</h2>
-<h1>Foo</h1>
-````````````````````````````````
-
-
-The heading content can be indented up to three spaces, and need
-not line up with the underlining:
-
-```````````````````````````````` example
- Foo
----
-
- Foo
------
-
- Foo
- ===
-.
-<h2>Foo</h2>
-<h2>Foo</h2>
-<h1>Foo</h1>
-````````````````````````````````
-
-
-Four spaces indent is too much:
-
-```````````````````````````````` example
- Foo
- ---
-
- Foo
----
-.
-<pre><code>Foo
----
-
-Foo
-</code></pre>
-<hr />
-````````````````````````````````
-
-
-The setext heading underline can be indented up to three spaces, and
-may have trailing spaces:
-
-```````````````````````````````` example
-Foo
- ----
-.
-<h2>Foo</h2>
-````````````````````````````````
-
-
-Four spaces is too much:
-
-```````````````````````````````` example
-Foo
- ---
-.
-<p>Foo
----</p>
-````````````````````````````````
-
-
-The setext heading underline cannot contain internal spaces:
-
-```````````````````````````````` example
-Foo
-= =
-
-Foo
---- -
-.
-<p>Foo
-= =</p>
-<p>Foo</p>
-<hr />
-````````````````````````````````
-
-
-Trailing spaces in the content line do not cause a line break:
-
-```````````````````````````````` example
-Foo
------
-.
-<h2>Foo</h2>
-````````````````````````````````
-
-
-Nor does a backslash at the end:
-
-```````````````````````````````` example
-Foo\
-----
-.
-<h2>Foo\</h2>
-````````````````````````````````
-
-
-Since indicators of block structure take precedence over
-indicators of inline structure, the following are setext headings:
-
-```````````````````````````````` example
-`Foo
-----
-`
-
-<a title="a lot
----
-of dashes"/>
-.
-<h2>`Foo</h2>
-<p>`</p>
-<h2><a title="a lot</h2>
-<p>of dashes"/></p>
-````````````````````````````````
-
-
-The setext heading underline cannot be a [lazy continuation
-line] in a list item or block quote:
-
-```````````````````````````````` example
-> Foo
----
-.
-<blockquote>
-<p>Foo</p>
-</blockquote>
-<hr />
-````````````````````````````````
-
-
-```````````````````````````````` example
-> foo
-bar
-===
-.
-<blockquote>
-<p>foo
-bar
-===</p>
-</blockquote>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- Foo
----
-.
-<ul>
-<li>Foo</li>
-</ul>
-<hr />
-````````````````````````````````
-
-
-A blank line is needed between a paragraph and a following
-setext heading, since otherwise the paragraph becomes part
-of the heading's content:
-
-```````````````````````````````` example
-Foo
-Bar
----
-.
-<h2>Foo
-Bar</h2>
-````````````````````````````````
-
-
-But in general a blank line is not required before or after
-setext headings:
-
-```````````````````````````````` example
----
-Foo
----
-Bar
----
-Baz
-.
-<hr />
-<h2>Foo</h2>
-<h2>Bar</h2>
-<p>Baz</p>
-````````````````````````````````
-
-
-Setext headings cannot be empty:
-
-```````````````````````````````` example
-
-====
-.
-<p>====</p>
-````````````````````````````````
-
-
-Setext heading text lines must not be interpretable as block
-constructs other than paragraphs. So, the line of dashes
-in these examples gets interpreted as a thematic break:
-
-```````````````````````````````` example
----
----
-.
-<hr />
-<hr />
-````````````````````````````````
-
-
-```````````````````````````````` example
-- foo
------
-.
-<ul>
-<li>foo</li>
-</ul>
-<hr />
-````````````````````````````````
-
-
-```````````````````````````````` example
- foo
----
-.
-<pre><code>foo
-</code></pre>
-<hr />
-````````````````````````````````
-
-
-```````````````````````````````` example
-> foo
------
-.
-<blockquote>
-<p>foo</p>
-</blockquote>
-<hr />
-````````````````````````````````
-
-
-If you want a heading with `> foo` as its literal text, you can
-use backslash escapes:
-
-```````````````````````````````` example
-\> foo
-------
-.
-<h2>> foo</h2>
-````````````````````````````````
-
-
-**Compatibility note:** Most existing Markdown implementations
-do not allow the text of setext headings to span multiple lines.
-But there is no consensus about how to interpret
-
-``` markdown
-Foo
-bar
----
-baz
-```
-
-One can find four different interpretations:
-
-1. paragraph "Foo", heading "bar", paragraph "baz"
-2. paragraph "Foo bar", thematic break, paragraph "baz"
-3. paragraph "Foo bar --- baz"
-4. heading "Foo bar", paragraph "baz"
-
-We find interpretation 4 most natural, and interpretation 4
-increases the expressive power of CommonMark, by allowing
-multiline headings. Authors who want interpretation 1 can
-put a blank line after the first paragraph:
-
-```````````````````````````````` example
-Foo
-
-bar
----
-baz
-.
-<p>Foo</p>
-<h2>bar</h2>
-<p>baz</p>
-````````````````````````````````
-
-
-Authors who want interpretation 2 can put blank lines around
-the thematic break,
-
-```````````````````````````````` example
-Foo
-bar
-
----
-
-baz
-.
-<p>Foo
-bar</p>
-<hr />
-<p>baz</p>
-````````````````````````````````
-
-
-or use a thematic break that cannot count as a [setext heading
-underline], such as
-
-```````````````````````````````` example
-Foo
-bar
-* * *
-baz
-.
-<p>Foo
-bar</p>
-<hr />
-<p>baz</p>
-````````````````````````````````
-
-
-Authors who want interpretation 3 can use backslash escapes:
-
-```````````````````````````````` example
-Foo
-bar
-\---
-baz
-.
-<p>Foo
-bar
----
-baz</p>
-````````````````````````````````
-
-
-## Indented code blocks
-
-An [indented code block](@) is composed of one or more
-[indented chunks] separated by blank lines.
-An [indented chunk](@) is a sequence of non-blank lines,
-each indented four or more spaces. The contents of the code block are
-the literal contents of the lines, including trailing
-[line endings], minus four spaces of indentation.
-An indented code block has no [info string].
-
-An indented code block cannot interrupt a paragraph, so there must be
-a blank line between a paragraph and a following indented code block.
-(A blank line is not needed, however, between a code block and a following
-paragraph.)
-
-```````````````````````````````` example
- a simple
- indented code block
-.
-<pre><code>a simple
- indented code block
-</code></pre>
-````````````````````````````````
-
-
-If there is any ambiguity between an interpretation of indentation
-as a code block and as indicating that material belongs to a [list
-item][list items], the list item interpretation takes precedence:
-
-```````````````````````````````` example
- - foo
-
- bar
-.
-<ul>
-<li>
-<p>foo</p>
-<p>bar</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-1. foo
-
- - bar
-.
-<ol>
-<li>
-<p>foo</p>
-<ul>
-<li>bar</li>
-</ul>
-</li>
-</ol>
-````````````````````````````````
-
-
-
-The contents of a code block are literal text, and do not get parsed
-as Markdown:
-
-```````````````````````````````` example
- <a/>
- *hi*
-
- - one
-.
-<pre><code><a/>
-*hi*
-
-- one
-</code></pre>
-````````````````````````````````
-
-
-Here we have three chunks separated by blank lines:
-
-```````````````````````````````` example
- chunk1
-
- chunk2
-
-
-
- chunk3
-.
-<pre><code>chunk1
-
-chunk2
-
-
-
-chunk3
-</code></pre>
-````````````````````````````````
-
-
-Any initial spaces beyond four will be included in the content, even
-in interior blank lines:
-
-```````````````````````````````` example
- chunk1
-
- chunk2
-.
-<pre><code>chunk1
-
- chunk2
-</code></pre>
-````````````````````````````````
-
-
-An indented code block cannot interrupt a paragraph. (This
-allows hanging indents and the like.)
-
-```````````````````````````````` example
-Foo
- bar
-
-.
-<p>Foo
-bar</p>
-````````````````````````````````
-
-
-However, any non-blank line with fewer than four leading spaces ends
-the code block immediately. So a paragraph may occur immediately
-after indented code:
-
-```````````````````````````````` example
- foo
-bar
-.
-<pre><code>foo
-</code></pre>
-<p>bar</p>
-````````````````````````````````
-
-
-And indented code can occur immediately before and after other kinds of
-blocks:
-
-```````````````````````````````` example
-# Heading
- foo
-Heading
-------
- foo
-----
-.
-<h1>Heading</h1>
-<pre><code>foo
-</code></pre>
-<h2>Heading</h2>
-<pre><code>foo
-</code></pre>
-<hr />
-````````````````````````````````
-
-
-The first line can be indented more than four spaces:
-
-```````````````````````````````` example
- foo
- bar
-.
-<pre><code> foo
-bar
-</code></pre>
-````````````````````````````````
-
-
-Blank lines preceding or following an indented code block
-are not included in it:
-
-```````````````````````````````` example
-
-
- foo
-
-
-.
-<pre><code>foo
-</code></pre>
-````````````````````````````````
-
-
-Trailing spaces are included in the code block's content:
-
-```````````````````````````````` example
- foo
-.
-<pre><code>foo
-</code></pre>
-````````````````````````````````
-
-
-
-## Fenced code blocks
-
-A [code fence](@) is a sequence
-of at least three consecutive backtick characters (`` ` ``) or
-tildes (`~`). (Tildes and backticks cannot be mixed.)
-A [fenced code block](@)
-begins with a code fence, indented no more than three spaces.
-
-The line with the opening code fence may optionally contain some text
-following the code fence; this is trimmed of leading and trailing
-spaces and called the [info string](@).
-The [info string] may not contain any backtick
-characters. (The reason for this restriction is that otherwise
-some inline code would be incorrectly interpreted as the
-beginning of a fenced code block.)
-
-The content of the code block consists of all subsequent lines, until
-a closing [code fence] of the same type as the code block
-began with (backticks or tildes), and with at least as many backticks
-or tildes as the opening code fence. If the leading code fence is
-indented N spaces, then up to N spaces of indentation are removed from
-each line of the content (if present). (If a content line is not
-indented, it is preserved unchanged. If it is indented less than N
-spaces, all of the indentation is removed.)
-
-The closing code fence may be indented up to three spaces, and may be
-followed only by spaces, which are ignored. If the end of the
-containing block (or document) is reached and no closing code fence
-has been found, the code block contains all of the lines after the
-opening code fence until the end of the containing block (or
-document). (An alternative spec would require backtracking in the
-event that a closing code fence is not found. But this makes parsing
-much less efficient, and there seems to be no real down side to the
-behavior described here.)
-
-A fenced code block may interrupt a paragraph, and does not require
-a blank line either before or after.
-
-The content of a code fence is treated as literal text, not parsed
-as inlines. The first word of the [info string] is typically used to
-specify the language of the code sample, and rendered in the `class`
-attribute of the `code` tag. However, this spec does not mandate any
-particular treatment of the [info string].
-
-Here is a simple example with backticks:
-
-```````````````````````````````` example
-```
-<
- >
-```
-.
-<pre><code><
- >
-</code></pre>
-````````````````````````````````
-
-
-With tildes:
-
-```````````````````````````````` example
-~~~
-<
- >
-~~~
-.
-<pre><code><
- >
-</code></pre>
-````````````````````````````````
-
-
-The closing code fence must use the same character as the opening
-fence:
-
-```````````````````````````````` example
-```
-aaa
-~~~
-```
-.
-<pre><code>aaa
-~~~
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-~~~
-aaa
-```
-~~~
-.
-<pre><code>aaa
-```
-</code></pre>
-````````````````````````````````
-
-
-The closing code fence must be at least as long as the opening fence:
-
-```````````````````````````````` example
-````
-aaa
-```
-``````
-.
-<pre><code>aaa
-```
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-~~~~
-aaa
-~~~
-~~~~
-.
-<pre><code>aaa
-~~~
-</code></pre>
-````````````````````````````````
-
-
-Unclosed code blocks are closed by the end of the document
-(or the enclosing [block quote][block quotes] or [list item][list items]):
-
-```````````````````````````````` example
-```
-.
-<pre><code></code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-`````
-
-```
-aaa
-.
-<pre><code>
-```
-aaa
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-> ```
-> aaa
-
-bbb
-.
-<blockquote>
-<pre><code>aaa
-</code></pre>
-</blockquote>
-<p>bbb</p>
-````````````````````````````````
-
-
-A code block can have all empty lines as its content:
-
-```````````````````````````````` example
-```
-
-
-```
-.
-<pre><code>
-
-</code></pre>
-````````````````````````````````
-
-
-A code block can be empty:
-
-```````````````````````````````` example
-```
-```
-.
-<pre><code></code></pre>
-````````````````````````````````
-
-
-Fences can be indented. If the opening fence is indented,
-content lines will have equivalent opening indentation removed,
-if present:
-
-```````````````````````````````` example
- ```
- aaa
-aaa
-```
-.
-<pre><code>aaa
-aaa
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
- ```
-aaa
- aaa
-aaa
- ```
-.
-<pre><code>aaa
-aaa
-aaa
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
- ```
- aaa
- aaa
- aaa
- ```
-.
-<pre><code>aaa
- aaa
-aaa
-</code></pre>
-````````````````````````````````
-
-
-Four spaces indentation produces an indented code block:
-
-```````````````````````````````` example
- ```
- aaa
- ```
-.
-<pre><code>```
-aaa
-```
-</code></pre>
-````````````````````````````````
-
-
-Closing fences may be indented by 0-3 spaces, and their indentation
-need not match that of the opening fence:
-
-```````````````````````````````` example
-```
-aaa
- ```
-.
-<pre><code>aaa
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
- ```
-aaa
- ```
-.
-<pre><code>aaa
-</code></pre>
-````````````````````````````````
-
-
-This is not a closing fence, because it is indented 4 spaces:
-
-```````````````````````````````` example
-```
-aaa
- ```
-.
-<pre><code>aaa
- ```
-</code></pre>
-````````````````````````````````
-
-
-
-Code fences (opening and closing) cannot contain internal spaces:
-
-```````````````````````````````` example
-``` ```
-aaa
-.
-<p><code></code>
-aaa</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-~~~~~~
-aaa
-~~~ ~~
-.
-<pre><code>aaa
-~~~ ~~
-</code></pre>
-````````````````````````````````
-
-
-Fenced code blocks can interrupt paragraphs, and can be followed
-directly by paragraphs, without a blank line between:
-
-```````````````````````````````` example
-foo
-```
-bar
-```
-baz
-.
-<p>foo</p>
-<pre><code>bar
-</code></pre>
-<p>baz</p>
-````````````````````````````````
-
-
-Other blocks can also occur before and after fenced code blocks
-without an intervening blank line:
-
-```````````````````````````````` example
-foo
----
-~~~
-bar
-~~~
-# baz
-.
-<h2>foo</h2>
-<pre><code>bar
-</code></pre>
-<h1>baz</h1>
-````````````````````````````````
-
-
-An [info string] can be provided after the opening code fence.
-Opening and closing spaces will be stripped, and the first word, prefixed
-with `language-`, is used as the value for the `class` attribute of the
-`code` element within the enclosing `pre` element.
-
-```````````````````````````````` example
-```ruby
-def foo(x)
- return 3
-end
-```
-.
-<pre><code class="language-ruby">def foo(x)
- return 3
-end
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-~~~~ ruby startline=3 $%@#$
-def foo(x)
- return 3
-end
-~~~~~~~
-.
-<pre><code class="language-ruby">def foo(x)
- return 3
-end
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-````;
-````
-.
-<pre><code class="language-;"></code></pre>
-````````````````````````````````
-
-
-[Info strings] for backtick code blocks cannot contain backticks:
-
-```````````````````````````````` example
-``` aa ```
-foo
-.
-<p><code>aa</code>
-foo</p>
-````````````````````````````````
-
-
-Closing code fences cannot have [info strings]:
-
-```````````````````````````````` example
-```
-``` aaa
-```
-.
-<pre><code>``` aaa
-</code></pre>
-````````````````````````````````
-
-
-
-## HTML blocks
-
-An [HTML block](@) is a group of lines that is treated
-as raw HTML (and will not be escaped in HTML output).
-
-There are seven kinds of [HTML block], which can be defined
-by their start and end conditions. The block begins with a line that
-meets a [start condition](@) (after up to three spaces
-optional indentation). It ends with the first subsequent line that
-meets a matching [end condition](@), or the last line of
-the document, if no line is encountered that meets the
-[end condition]. If the first line meets both the [start condition]
-and the [end condition], the block will contain just that line.
-
-1. **Start condition:** line begins with the string `<script`,
-`<pre`, or `<style` (case-insensitive), followed by whitespace,
-the string `>`, or the end of the line.\
-**End condition:** line contains an end tag
-`</script>`, `</pre>`, or `</style>` (case-insensitive; it
-need not match the start tag).
-
-2. **Start condition:** line begins with the string `<!--`.\
-**End condition:** line contains the string `-->`.
-
-3. **Start condition:** line begins with the string `<?`.\
-**End condition:** line contains the string `?>`.
-
-4. **Start condition:** line begins with the string `<!`
-followed by an uppercase ASCII letter.\
-**End condition:** line contains the character `>`.
-
-5. **Start condition:** line begins with the string
-`<![CDATA[`.\
-**End condition:** line contains the string `]]>`.
-
-6. **Start condition:** line begins the string `<` or `</`
-followed by one of the strings (case-insensitive) `address`,
-`article`, `aside`, `base`, `basefont`, `blockquote`, `body`,
-`caption`, `center`, `col`, `colgroup`, `dd`, `details`, `dialog`,
-`dir`, `div`, `dl`, `dt`, `fieldset`, `figcaption`, `figure`,
-`footer`, `form`, `frame`, `frameset`, `h1`, `head`, `header`, `hr`,
-`html`, `iframe`, `legend`, `li`, `link`, `main`, `menu`, `menuitem`,
-`meta`, `nav`, `noframes`, `ol`, `optgroup`, `option`, `p`, `param`,
-`section`, `source`, `summary`, `table`, `tbody`, `td`,
-`tfoot`, `th`, `thead`, `title`, `tr`, `track`, `ul`, followed
-by [whitespace], the end of the line, the string `>`, or
-the string `/>`.\
-**End condition:** line is followed by a [blank line].
-
-7. **Start condition:** line begins with a complete [open tag]
-or [closing tag] (with any [tag name] other than `script`,
-`style`, or `pre`) followed only by [whitespace]
-or the end of the line.\
-**End condition:** line is followed by a [blank line].
-
-All types of [HTML blocks] except type 7 may interrupt
-a paragraph. Blocks of type 7 may not interrupt a paragraph.
-(This restriction is intended to prevent unwanted interpretation
-of long tags inside a wrapped paragraph as starting HTML blocks.)
-
-Some simple examples follow. Here are some basic HTML blocks
-of type 6:
-
-```````````````````````````````` example
-<table>
- <tr>
- <td>
- hi
- </td>
- </tr>
-</table>
-
-okay.
-.
-<table>
- <tr>
- <td>
- hi
- </td>
- </tr>
-</table>
-<p>okay.</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
- <div>
- *hello*
- <foo><a>
-.
- <div>
- *hello*
- <foo><a>
-````````````````````````````````
-
-
-A block can also start with a closing tag:
-
-```````````````````````````````` example
-</div>
-*foo*
-.
-</div>
-*foo*
-````````````````````````````````
-
-
-Here we have two HTML blocks with a Markdown paragraph between them:
-
-```````````````````````````````` example
-<DIV CLASS="foo">
-
-*Markdown*
-
-</DIV>
-.
-<DIV CLASS="foo">
-<p><em>Markdown</em></p>
-</DIV>
-````````````````````````````````
-
-
-The tag on the first line can be partial, as long
-as it is split where there would be whitespace:
-
-```````````````````````````````` example
-<div id="foo"
- class="bar">
-</div>
-.
-<div id="foo"
- class="bar">
-</div>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<div id="foo" class="bar
- baz">
-</div>
-.
-<div id="foo" class="bar
- baz">
-</div>
-````````````````````````````````
-
-
-An open tag need not be closed:
-```````````````````````````````` example
-<div>
-*foo*
-
-*bar*
-.
-<div>
-*foo*
-<p><em>bar</em></p>
-````````````````````````````````
-
-
-
-A partial tag need not even be completed (garbage
-in, garbage out):
-
-```````````````````````````````` example
-<div id="foo"
-*hi*
-.
-<div id="foo"
-*hi*
-````````````````````````````````
-
-
-```````````````````````````````` example
-<div class
-foo
-.
-<div class
-foo
-````````````````````````````````
-
-
-The initial tag doesn't even need to be a valid
-tag, as long as it starts like one:
-
-```````````````````````````````` example
-<div *???-&&&-<---
-*foo*
-.
-<div *???-&&&-<---
-*foo*
-````````````````````````````````
-
-
-In type 6 blocks, the initial tag need not be on a line by
-itself:
-
-```````````````````````````````` example
-<div><a href="bar">*foo*</a></div>
-.
-<div><a href="bar">*foo*</a></div>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<table><tr><td>
-foo
-</td></tr></table>
-.
-<table><tr><td>
-foo
-</td></tr></table>
-````````````````````````````````
-
-
-Everything until the next blank line or end of document
-gets included in the HTML block. So, in the following
-example, what looks like a Markdown code block
-is actually part of the HTML block, which continues until a blank
-line or the end of the document is reached:
-
-```````````````````````````````` example
-<div></div>
-``` c
-int x = 33;
-```
-.
-<div></div>
-``` c
-int x = 33;
-```
-````````````````````````````````
-
-
-To start an [HTML block] with a tag that is *not* in the
-list of block-level tags in (6), you must put the tag by
-itself on the first line (and it must be complete):
-
-```````````````````````````````` example
-<a href="foo">
-*bar*
-</a>
-.
-<a href="foo">
-*bar*
-</a>
-````````````````````````````````
-
-
-In type 7 blocks, the [tag name] can be anything:
-
-```````````````````````````````` example
-<Warning>
-*bar*
-</Warning>
-.
-<Warning>
-*bar*
-</Warning>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<i class="foo">
-*bar*
-</i>
-.
-<i class="foo">
-*bar*
-</i>
-````````````````````````````````
-
-
-```````````````````````````````` example
-</ins>
-*bar*
-.
-</ins>
-*bar*
-````````````````````````````````
-
-
-These rules are designed to allow us to work with tags that
-can function as either block-level or inline-level tags.
-The `<del>` tag is a nice example. We can surround content with
-`<del>` tags in three different ways. In this case, we get a raw
-HTML block, because the `<del>` tag is on a line by itself:
-
-```````````````````````````````` example
-<del>
-*foo*
-</del>
-.
-<del>
-*foo*
-</del>
-````````````````````````````````
-
-
-In this case, we get a raw HTML block that just includes
-the `<del>` tag (because it ends with the following blank
-line). So the contents get interpreted as CommonMark:
-
-```````````````````````````````` example
-<del>
-
-*foo*
-
-</del>
-.
-<del>
-<p><em>foo</em></p>
-</del>
-````````````````````````````````
-
-
-Finally, in this case, the `<del>` tags are interpreted
-as [raw HTML] *inside* the CommonMark paragraph. (Because
-the tag is not on a line by itself, we get inline HTML
-rather than an [HTML block].)
-
-```````````````````````````````` example
-<del>*foo*</del>
-.
-<p><del><em>foo</em></del></p>
-````````````````````````````````
-
-
-HTML tags designed to contain literal content
-(`script`, `style`, `pre`), comments, processing instructions,
-and declarations are treated somewhat differently.
-Instead of ending at the first blank line, these blocks
-end at the first line containing a corresponding end tag.
-As a result, these blocks can contain blank lines:
-
-A pre tag (type 1):
-
-```````````````````````````````` example
-<pre language="haskell"><code>
-import Text.HTML.TagSoup
-
-main :: IO ()
-main = print $ parseTags tags
-</code></pre>
-.
-<pre language="haskell"><code>
-import Text.HTML.TagSoup
-
-main :: IO ()
-main = print $ parseTags tags
-</code></pre>
-````````````````````````````````
-
-
-A script tag (type 1):
-
-```````````````````````````````` example
-<script type="text/javascript">
-// JavaScript example
-
-document.getElementById("demo").innerHTML = "Hello JavaScript!";
-</script>
-.
-<script type="text/javascript">
-// JavaScript example
-
-document.getElementById("demo").innerHTML = "Hello JavaScript!";
-</script>
-````````````````````````````````
-
-
-A style tag (type 1):
-
-```````````````````````````````` example
-<style
- type="text/css">
-h1 {color:red;}
-
-p {color:blue;}
-</style>
-.
-<style
- type="text/css">
-h1 {color:red;}
-
-p {color:blue;}
-</style>
-````````````````````````````````
-
-
-If there is no matching end tag, the block will end at the
-end of the document (or the enclosing [block quote][block quotes]
-or [list item][list items]):
-
-```````````````````````````````` example
-<style
- type="text/css">
-
-foo
-.
-<style
- type="text/css">
-
-foo
-````````````````````````````````
-
-
-```````````````````````````````` example
-> <div>
-> foo
-
-bar
-.
-<blockquote>
-<div>
-foo
-</blockquote>
-<p>bar</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- <div>
-- foo
-.
-<ul>
-<li>
-<div>
-</li>
-<li>foo</li>
-</ul>
-````````````````````````````````
-
-
-The end tag can occur on the same line as the start tag:
-
-```````````````````````````````` example
-<style>p{color:red;}</style>
-*foo*
-.
-<style>p{color:red;}</style>
-<p><em>foo</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<!-- foo -->*bar*
-*baz*
-.
-<!-- foo -->*bar*
-<p><em>baz</em></p>
-````````````````````````````````
-
-
-Note that anything on the last line after the
-end tag will be included in the [HTML block]:
-
-```````````````````````````````` example
-<script>
-foo
-</script>1. *bar*
-.
-<script>
-foo
-</script>1. *bar*
-````````````````````````````````
-
-
-A comment (type 2):
-
-```````````````````````````````` example
-<!-- Foo
-
-bar
- baz -->
-.
-<!-- Foo
-
-bar
- baz -->
-````````````````````````````````
-
-
-
-A processing instruction (type 3):
-
-```````````````````````````````` example
-<?php
-
- echo '>';
-
-?>
-.
-<?php
-
- echo '>';
-
-?>
-````````````````````````````````
-
-
-A declaration (type 4):
-
-```````````````````````````````` example
-<!DOCTYPE html>
-.
-<!DOCTYPE html>
-````````````````````````````````
-
-
-CDATA (type 5):
-
-```````````````````````````````` example
-<![CDATA[
-function matchwo(a,b)
-{
- if (a < b && a < 0) then {
- return 1;
-
- } else {
-
- return 0;
- }
-}
-]]>
-.
-<![CDATA[
-function matchwo(a,b)
-{
- if (a < b && a < 0) then {
- return 1;
-
- } else {
-
- return 0;
- }
-}
-]]>
-````````````````````````````````
-
-
-The opening tag can be indented 1-3 spaces, but not 4:
-
-```````````````````````````````` example
- <!-- foo -->
-
- <!-- foo -->
-.
- <!-- foo -->
-<pre><code><!-- foo -->
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
- <div>
-
- <div>
-.
- <div>
-<pre><code><div>
-</code></pre>
-````````````````````````````````
-
-
-An HTML block of types 1--6 can interrupt a paragraph, and need not be
-preceded by a blank line.
-
-```````````````````````````````` example
-Foo
-<div>
-bar
-</div>
-.
-<p>Foo</p>
-<div>
-bar
-</div>
-````````````````````````````````
-
-
-However, a following blank line is needed, except at the end of
-a document, and except for blocks of types 1--5, above:
-
-```````````````````````````````` example
-<div>
-bar
-</div>
-*foo*
-.
-<div>
-bar
-</div>
-*foo*
-````````````````````````````````
-
-
-HTML blocks of type 7 cannot interrupt a paragraph:
-
-```````````````````````````````` example
-Foo
-<a href="bar">
-baz
-.
-<p>Foo
-<a href="bar">
-baz</p>
-````````````````````````````````
-
-
-This rule differs from John Gruber's original Markdown syntax
-specification, which says:
-
-> The only restrictions are that block-level HTML elements —
-> e.g. `<div>`, `<table>`, `<pre>`, `<p>`, etc. — must be separated from
-> surrounding content by blank lines, and the start and end tags of the
-> block should not be indented with tabs or spaces.
-
-In some ways Gruber's rule is more restrictive than the one given
-here:
-
-- It requires that an HTML block be preceded by a blank line.
-- It does not allow the start tag to be indented.
-- It requires a matching end tag, which it also does not allow to
- be indented.
-
-Most Markdown implementations (including some of Gruber's own) do not
-respect all of these restrictions.
-
-There is one respect, however, in which Gruber's rule is more liberal
-than the one given here, since it allows blank lines to occur inside
-an HTML block. There are two reasons for disallowing them here.
-First, it removes the need to parse balanced tags, which is
-expensive and can require backtracking from the end of the document
-if no matching end tag is found. Second, it provides a very simple
-and flexible way of including Markdown content inside HTML tags:
-simply separate the Markdown from the HTML using blank lines:
-
-Compare:
-
-```````````````````````````````` example
-<div>
-
-*Emphasized* text.
-
-</div>
-.
-<div>
-<p><em>Emphasized</em> text.</p>
-</div>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<div>
-*Emphasized* text.
-</div>
-.
-<div>
-*Emphasized* text.
-</div>
-````````````````````````````````
-
-
-Some Markdown implementations have adopted a convention of
-interpreting content inside tags as text if the open tag has
-the attribute `markdown=1`. The rule given above seems a simpler and
-more elegant way of achieving the same expressive power, which is also
-much simpler to parse.
-
-The main potential drawback is that one can no longer paste HTML
-blocks into Markdown documents with 100% reliability. However,
-*in most cases* this will work fine, because the blank lines in
-HTML are usually followed by HTML block tags. For example:
-
-```````````````````````````````` example
-<table>
-
-<tr>
-
-<td>
-Hi
-</td>
-
-</tr>
-
-</table>
-.
-<table>
-<tr>
-<td>
-Hi
-</td>
-</tr>
-</table>
-````````````````````````````````
-
-
-There are problems, however, if the inner tags are indented
-*and* separated by spaces, as then they will be interpreted as
-an indented code block:
-
-```````````````````````````````` example
-<table>
-
- <tr>
-
- <td>
- Hi
- </td>
-
- </tr>
-
-</table>
-.
-<table>
- <tr>
-<pre><code><td>
- Hi
-</td>
-</code></pre>
- </tr>
-</table>
-````````````````````````````````
-
-
-Fortunately, blank lines are usually not necessary and can be
-deleted. The exception is inside `<pre>` tags, but as described
-above, raw HTML blocks starting with `<pre>` *can* contain blank
-lines.
-
-## Link reference definitions
-
-A [link reference definition](@)
-consists of a [link label], indented up to three spaces, followed
-by a colon (`:`), optional [whitespace] (including up to one
-[line ending]), a [link destination],
-optional [whitespace] (including up to one
-[line ending]), and an optional [link
-title], which if it is present must be separated
-from the [link destination] by [whitespace].
-No further [non-whitespace characters] may occur on the line.
-
-A [link reference definition]
-does not correspond to a structural element of a document. Instead, it
-defines a label which can be used in [reference links]
-and reference-style [images] elsewhere in the document. [Link
-reference definitions] can come either before or after the links that use
-them.
-
-```````````````````````````````` example
-[foo]: /url "title"
-
-[foo]
-.
-<p><a href="/url" title="title">foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
- [foo]:
- /url
- 'the title'
-
-[foo]
-.
-<p><a href="/url" title="the title">foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[Foo*bar\]]:my_(url) 'title (with parens)'
-
-[Foo*bar\]]
-.
-<p><a href="my_(url)" title="title (with parens)">Foo*bar]</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[Foo bar]:
-<my%20url>
-'title'
-
-[Foo bar]
-.
-<p><a href="my%20url" title="title">Foo bar</a></p>
-````````````````````````````````
-
-
-The title may extend over multiple lines:
-
-```````````````````````````````` example
-[foo]: /url '
-title
-line1
-line2
-'
-
-[foo]
-.
-<p><a href="/url" title="
-title
-line1
-line2
-">foo</a></p>
-````````````````````````````````
-
-
-However, it may not contain a [blank line]:
-
-```````````````````````````````` example
-[foo]: /url 'title
-
-with blank line'
-
-[foo]
-.
-<p>[foo]: /url 'title</p>
-<p>with blank line'</p>
-<p>[foo]</p>
-````````````````````````````````
-
-
-The title may be omitted:
-
-```````````````````````````````` example
-[foo]:
-/url
-
-[foo]
-.
-<p><a href="/url">foo</a></p>
-````````````````````````````````
-
-
-The link destination may not be omitted:
-
-```````````````````````````````` example
-[foo]:
-
-[foo]
-.
-<p>[foo]:</p>
-<p>[foo]</p>
-````````````````````````````````
-
-
-Both title and destination can contain backslash escapes
-and literal backslashes:
-
-```````````````````````````````` example
-[foo]: /url\bar\*baz "foo\"bar\baz"
-
-[foo]
-.
-<p><a href="/url%5Cbar*baz" title="foo"bar\baz">foo</a></p>
-````````````````````````````````
-
-
-A link can come before its corresponding definition:
-
-```````````````````````````````` example
-[foo]
-
-[foo]: url
-.
-<p><a href="url">foo</a></p>
-````````````````````````````````
-
-
-If there are several matching definitions, the first one takes
-precedence:
-
-```````````````````````````````` example
-[foo]
-
-[foo]: first
-[foo]: second
-.
-<p><a href="first">foo</a></p>
-````````````````````````````````
-
-
-As noted in the section on [Links], matching of labels is
-case-insensitive (see [matches]).
-
-```````````````````````````````` example
-[FOO]: /url
-
-[Foo]
-.
-<p><a href="/url">Foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[ΑΓΩ]: /φου
-
-[αγω]
-.
-<p><a href="/%CF%86%CE%BF%CF%85">αγω</a></p>
-````````````````````````````````
-
-
-Here is a link reference definition with no corresponding link.
-It contributes nothing to the document.
-
-```````````````````````````````` example
-[foo]: /url
-.
-````````````````````````````````
-
-
-Here is another one:
-
-```````````````````````````````` example
-[
-foo
-]: /url
-bar
-.
-<p>bar</p>
-````````````````````````````````
-
-
-This is not a link reference definition, because there are
-[non-whitespace characters] after the title:
-
-```````````````````````````````` example
-[foo]: /url "title" ok
-.
-<p>[foo]: /url "title" ok</p>
-````````````````````````````````
-
-
-This is a link reference definition, but it has no title:
-
-```````````````````````````````` example
-[foo]: /url
-"title" ok
-.
-<p>"title" ok</p>
-````````````````````````````````
-
-
-This is not a link reference definition, because it is indented
-four spaces:
-
-```````````````````````````````` example
- [foo]: /url "title"
-
-[foo]
-.
-<pre><code>[foo]: /url "title"
-</code></pre>
-<p>[foo]</p>
-````````````````````````````````
-
-
-This is not a link reference definition, because it occurs inside
-a code block:
-
-```````````````````````````````` example
-```
-[foo]: /url
-```
-
-[foo]
-.
-<pre><code>[foo]: /url
-</code></pre>
-<p>[foo]</p>
-````````````````````````````````
-
-
-A [link reference definition] cannot interrupt a paragraph.
-
-```````````````````````````````` example
-Foo
-[bar]: /baz
-
-[bar]
-.
-<p>Foo
-[bar]: /baz</p>
-<p>[bar]</p>
-````````````````````````````````
-
-
-However, it can directly follow other block elements, such as headings
-and thematic breaks, and it need not be followed by a blank line.
-
-```````````````````````````````` example
-# [Foo]
-[foo]: /url
-> bar
-.
-<h1><a href="/url">Foo</a></h1>
-<blockquote>
-<p>bar</p>
-</blockquote>
-````````````````````````````````
-
-
-Several [link reference definitions]
-can occur one after another, without intervening blank lines.
-
-```````````````````````````````` example
-[foo]: /foo-url "foo"
-[bar]: /bar-url
- "bar"
-[baz]: /baz-url
-
-[foo],
-[bar],
-[baz]
-.
-<p><a href="/foo-url" title="foo">foo</a>,
-<a href="/bar-url" title="bar">bar</a>,
-<a href="/baz-url">baz</a></p>
-````````````````````````````````
-
-
-[Link reference definitions] can occur
-inside block containers, like lists and block quotations. They
-affect the entire document, not just the container in which they
-are defined:
-
-```````````````````````````````` example
-[foo]
-
-> [foo]: /url
-.
-<p><a href="/url">foo</a></p>
-<blockquote>
-</blockquote>
-````````````````````````````````
-
-
-
-## Paragraphs
-
-A sequence of non-blank lines that cannot be interpreted as other
-kinds of blocks forms a [paragraph](@).
-The contents of the paragraph are the result of parsing the
-paragraph's raw content as inlines. The paragraph's raw content
-is formed by concatenating the lines and removing initial and final
-[whitespace].
-
-A simple example with two paragraphs:
-
-```````````````````````````````` example
-aaa
-
-bbb
-.
-<p>aaa</p>
-<p>bbb</p>
-````````````````````````````````
-
-
-Paragraphs can contain multiple lines, but no blank lines:
-
-```````````````````````````````` example
-aaa
-bbb
-
-ccc
-ddd
-.
-<p>aaa
-bbb</p>
-<p>ccc
-ddd</p>
-````````````````````````````````
-
-
-Multiple blank lines between paragraph have no effect:
-
-```````````````````````````````` example
-aaa
-
-
-bbb
-.
-<p>aaa</p>
-<p>bbb</p>
-````````````````````````````````
-
-
-Leading spaces are skipped:
-
-```````````````````````````````` example
- aaa
- bbb
-.
-<p>aaa
-bbb</p>
-````````````````````````````````
-
-
-Lines after the first may be indented any amount, since indented
-code blocks cannot interrupt paragraphs.
-
-```````````````````````````````` example
-aaa
- bbb
- ccc
-.
-<p>aaa
-bbb
-ccc</p>
-````````````````````````````````
-
-
-However, the first line may be indented at most three spaces,
-or an indented code block will be triggered:
-
-```````````````````````````````` example
- aaa
-bbb
-.
-<p>aaa
-bbb</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
- aaa
-bbb
-.
-<pre><code>aaa
-</code></pre>
-<p>bbb</p>
-````````````````````````````````
-
-
-Final spaces are stripped before inline parsing, so a paragraph
-that ends with two or more spaces will not end with a [hard line
-break]:
-
-```````````````````````````````` example
-aaa
-bbb
-.
-<p>aaa<br />
-bbb</p>
-````````````````````````````````
-
-
-## Blank lines
-
-[Blank lines] between block-level elements are ignored,
-except for the role they play in determining whether a [list]
-is [tight] or [loose].
-
-Blank lines at the beginning and end of the document are also ignored.
-
-```````````````````````````````` example
-
-
-aaa
-
-
-# aaa
-
-
-.
-<p>aaa</p>
-<h1>aaa</h1>
-````````````````````````````````
-
-
-
-# Container blocks
-
-A [container block] is a block that has other
-blocks as its contents. There are two basic kinds of container blocks:
-[block quotes] and [list items].
-[Lists] are meta-containers for [list items].
-
-We define the syntax for container blocks recursively. The general
-form of the definition is:
-
-> If X is a sequence of blocks, then the result of
-> transforming X in such-and-such a way is a container of type Y
-> with these blocks as its content.
-
-So, we explain what counts as a block quote or list item by explaining
-how these can be *generated* from their contents. This should suffice
-to define the syntax, although it does not give a recipe for *parsing*
-these constructions. (A recipe is provided below in the section entitled
-[A parsing strategy](#appendix-a-parsing-strategy).)
-
-## Block quotes
-
-A [block quote marker](@)
-consists of 0-3 spaces of initial indent, plus (a) the character `>` together
-with a following space, or (b) a single character `>` not followed by a space.
-
-The following rules define [block quotes]:
-
-1. **Basic case.** If a string of lines *Ls* constitute a sequence
- of blocks *Bs*, then the result of prepending a [block quote
- marker] to the beginning of each line in *Ls*
- is a [block quote](#block-quotes) containing *Bs*.
-
-2. **Laziness.** If a string of lines *Ls* constitute a [block
- quote](#block-quotes) with contents *Bs*, then the result of deleting
- the initial [block quote marker] from one or
- more lines in which the next [non-whitespace character] after the [block
- quote marker] is [paragraph continuation
- text] is a block quote with *Bs* as its content.
- [Paragraph continuation text](@) is text
- that will be parsed as part of the content of a paragraph, but does
- not occur at the beginning of the paragraph.
-
-3. **Consecutiveness.** A document cannot contain two [block
- quotes] in a row unless there is a [blank line] between them.
-
-Nothing else counts as a [block quote](#block-quotes).
-
-Here is a simple example:
-
-```````````````````````````````` example
-> # Foo
-> bar
-> baz
-.
-<blockquote>
-<h1>Foo</h1>
-<p>bar
-baz</p>
-</blockquote>
-````````````````````````````````
-
-
-The spaces after the `>` characters can be omitted:
-
-```````````````````````````````` example
-># Foo
->bar
-> baz
-.
-<blockquote>
-<h1>Foo</h1>
-<p>bar
-baz</p>
-</blockquote>
-````````````````````````````````
-
-
-The `>` characters can be indented 1-3 spaces:
-
-```````````````````````````````` example
- > # Foo
- > bar
- > baz
-.
-<blockquote>
-<h1>Foo</h1>
-<p>bar
-baz</p>
-</blockquote>
-````````````````````````````````
-
-
-Four spaces gives us a code block:
-
-```````````````````````````````` example
- > # Foo
- > bar
- > baz
-.
-<pre><code>> # Foo
-> bar
-> baz
-</code></pre>
-````````````````````````````````
-
-
-The Laziness clause allows us to omit the `>` before a
-paragraph continuation line:
-
-```````````````````````````````` example
-> # Foo
-> bar
-baz
-.
-<blockquote>
-<h1>Foo</h1>
-<p>bar
-baz</p>
-</blockquote>
-````````````````````````````````
-
-
-A block quote can contain some lazy and some non-lazy
-continuation lines:
-
-```````````````````````````````` example
-> bar
-baz
-> foo
-.
-<blockquote>
-<p>bar
-baz
-foo</p>
-</blockquote>
-````````````````````````````````
-
-
-Laziness only applies to lines that would have been continuations of
-paragraphs had they been prepended with [block quote markers].
-For example, the `> ` cannot be omitted in the second line of
-
-``` markdown
-> foo
-> ---
-```
-
-without changing the meaning:
-
-```````````````````````````````` example
-> foo
----
-.
-<blockquote>
-<p>foo</p>
-</blockquote>
-<hr />
-````````````````````````````````
-
-
-Similarly, if we omit the `> ` in the second line of
-
-``` markdown
-> - foo
-> - bar
-```
-
-then the block quote ends after the first line:
-
-```````````````````````````````` example
-> - foo
-- bar
-.
-<blockquote>
-<ul>
-<li>foo</li>
-</ul>
-</blockquote>
-<ul>
-<li>bar</li>
-</ul>
-````````````````````````````````
-
-
-For the same reason, we can't omit the `> ` in front of
-subsequent lines of an indented or fenced code block:
-
-```````````````````````````````` example
-> foo
- bar
-.
-<blockquote>
-<pre><code>foo
-</code></pre>
-</blockquote>
-<pre><code>bar
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-> ```
-foo
-```
-.
-<blockquote>
-<pre><code></code></pre>
-</blockquote>
-<p>foo</p>
-<pre><code></code></pre>
-````````````````````````````````
-
-
-Note that in the following case, we have a paragraph
-continuation line:
-
-```````````````````````````````` example
-> foo
- - bar
-.
-<blockquote>
-<p>foo
-- bar</p>
-</blockquote>
-````````````````````````````````
-
-
-To see why, note that in
-
-```markdown
-> foo
-> - bar
-```
-
-the `- bar` is indented too far to start a list, and can't
-be an indented code block because indented code blocks cannot
-interrupt paragraphs, so it is a [paragraph continuation line].
-
-A block quote can be empty:
-
-```````````````````````````````` example
->
-.
-<blockquote>
-</blockquote>
-````````````````````````````````
-
-
-```````````````````````````````` example
->
->
->
-.
-<blockquote>
-</blockquote>
-````````````````````````````````
-
-
-A block quote can have initial or final blank lines:
-
-```````````````````````````````` example
->
-> foo
->
-.
-<blockquote>
-<p>foo</p>
-</blockquote>
-````````````````````````````````
-
-
-A blank line always separates block quotes:
-
-```````````````````````````````` example
-> foo
-
-> bar
-.
-<blockquote>
-<p>foo</p>
-</blockquote>
-<blockquote>
-<p>bar</p>
-</blockquote>
-````````````````````````````````
-
-
-(Most current Markdown implementations, including John Gruber's
-original `Markdown.pl`, will parse this example as a single block quote
-with two paragraphs. But it seems better to allow the author to decide
-whether two block quotes or one are wanted.)
-
-Consecutiveness means that if we put these block quotes together,
-we get a single block quote:
-
-```````````````````````````````` example
-> foo
-> bar
-.
-<blockquote>
-<p>foo
-bar</p>
-</blockquote>
-````````````````````````````````
-
-
-To get a block quote with two paragraphs, use:
-
-```````````````````````````````` example
-> foo
->
-> bar
-.
-<blockquote>
-<p>foo</p>
-<p>bar</p>
-</blockquote>
-````````````````````````````````
-
-
-Block quotes can interrupt paragraphs:
-
-```````````````````````````````` example
-foo
-> bar
-.
-<p>foo</p>
-<blockquote>
-<p>bar</p>
-</blockquote>
-````````````````````````````````
-
-
-In general, blank lines are not needed before or after block
-quotes:
-
-```````````````````````````````` example
-> aaa
-***
-> bbb
-.
-<blockquote>
-<p>aaa</p>
-</blockquote>
-<hr />
-<blockquote>
-<p>bbb</p>
-</blockquote>
-````````````````````````````````
-
-
-However, because of laziness, a blank line is needed between
-a block quote and a following paragraph:
-
-```````````````````````````````` example
-> bar
-baz
-.
-<blockquote>
-<p>bar
-baz</p>
-</blockquote>
-````````````````````````````````
-
-
-```````````````````````````````` example
-> bar
-
-baz
-.
-<blockquote>
-<p>bar</p>
-</blockquote>
-<p>baz</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-> bar
->
-baz
-.
-<blockquote>
-<p>bar</p>
-</blockquote>
-<p>baz</p>
-````````````````````````````````
-
-
-It is a consequence of the Laziness rule that any number
-of initial `>`s may be omitted on a continuation line of a
-nested block quote:
-
-```````````````````````````````` example
-> > > foo
-bar
-.
-<blockquote>
-<blockquote>
-<blockquote>
-<p>foo
-bar</p>
-</blockquote>
-</blockquote>
-</blockquote>
-````````````````````````````````
-
-
-```````````````````````````````` example
->>> foo
-> bar
->>baz
-.
-<blockquote>
-<blockquote>
-<blockquote>
-<p>foo
-bar
-baz</p>
-</blockquote>
-</blockquote>
-</blockquote>
-````````````````````````````````
-
-
-When including an indented code block in a block quote,
-remember that the [block quote marker] includes
-both the `>` and a following space. So *five spaces* are needed after
-the `>`:
-
-```````````````````````````````` example
-> code
-
-> not code
-.
-<blockquote>
-<pre><code>code
-</code></pre>
-</blockquote>
-<blockquote>
-<p>not code</p>
-</blockquote>
-````````````````````````````````
-
-
-
-## List items
-
-A [list marker](@) is a
-[bullet list marker] or an [ordered list marker].
-
-A [bullet list marker](@)
-is a `-`, `+`, or `*` character.
-
-An [ordered list marker](@)
-is a sequence of 1--9 arabic digits (`0-9`), followed by either a
-`.` character or a `)` character. (The reason for the length
-limit is that with 10 digits we start seeing integer overflows
-in some browsers.)
-
-The following rules define [list items]:
-
-1. **Basic case.** If a sequence of lines *Ls* constitute a sequence of
- blocks *Bs* starting with a [non-whitespace character] and not separated
- from each other by more than one blank line, and *M* is a list
- marker of width *W* followed by 0 < *N* < 5 spaces, then the result
- of prepending *M* and the following spaces to the first line of
- *Ls*, and indenting subsequent lines of *Ls* by *W + N* spaces, is a
- list item with *Bs* as its contents. The type of the list item
- (bullet or ordered) is determined by the type of its list marker.
- If the list item is ordered, then it is also assigned a start
- number, based on the ordered list marker.
-
-For example, let *Ls* be the lines
-
-```````````````````````````````` example
-A paragraph
-with two lines.
-
- indented code
-
-> A block quote.
-.
-<p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote>
-````````````````````````````````
-
-
-And let *M* be the marker `1.`, and *N* = 2. Then rule #1 says
-that the following is an ordered list item with start number 1,
-and the same contents as *Ls*:
-
-```````````````````````````````` example
-1. A paragraph
- with two lines.
-
- indented code
-
- > A block quote.
-.
-<ol>
-<li>
-<p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote>
-</li>
-</ol>
-````````````````````````````````
-
-
-The most important thing to notice is that the position of
-the text after the list marker determines how much indentation
-is needed in subsequent blocks in the list item. If the list
-marker takes up two spaces, and there are three spaces between
-the list marker and the next [non-whitespace character], then blocks
-must be indented five spaces in order to fall under the list
-item.
-
-Here are some examples showing how far content must be indented to be
-put under the list item:
-
-```````````````````````````````` example
-- one
-
- two
-.
-<ul>
-<li>one</li>
-</ul>
-<p>two</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- one
-
- two
-.
-<ul>
-<li>
-<p>one</p>
-<p>two</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
- - one
-
- two
-.
-<ul>
-<li>one</li>
-</ul>
-<pre><code> two
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
- - one
-
- two
-.
-<ul>
-<li>
-<p>one</p>
-<p>two</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-It is tempting to think of this in terms of columns: the continuation
-blocks must be indented at least to the column of the first
-[non-whitespace character] after the list marker. However, that is not quite right.
-The spaces after the list marker determine how much relative indentation
-is needed. Which column this indentation reaches will depend on
-how the list item is embedded in other constructions, as shown by
-this example:
-
-```````````````````````````````` example
- > > 1. one
->>
->> two
-.
-<blockquote>
-<blockquote>
-<ol>
-<li>
-<p>one</p>
-<p>two</p>
-</li>
-</ol>
-</blockquote>
-</blockquote>
-````````````````````````````````
-
-
-Here `two` occurs in the same column as the list marker `1.`,
-but is actually contained in the list item, because there is
-sufficient indentation after the last containing blockquote marker.
-
-The converse is also possible. In the following example, the word `two`
-occurs far to the right of the initial text of the list item, `one`, but
-it is not considered part of the list item, because it is not indented
-far enough past the blockquote marker:
-
-```````````````````````````````` example
->>- one
->>
- > > two
-.
-<blockquote>
-<blockquote>
-<ul>
-<li>one</li>
-</ul>
-<p>two</p>
-</blockquote>
-</blockquote>
-````````````````````````````````
-
-
-Note that at least one space is needed between the list marker and
-any following content, so these are not list items:
-
-```````````````````````````````` example
--one
-
-2.two
-.
-<p>-one</p>
-<p>2.two</p>
-````````````````````````````````
-
-
-A list item may not contain blocks that are separated by more than
-one blank line. Thus, two blank lines will end a list, unless the
-two blanks are contained in a [fenced code block].
-
-```````````````````````````````` example
-- foo
-
- bar
-
-- foo
-
-
- bar
-
-- ```
- foo
-
-
- bar
- ```
-
-- baz
-
- + ```
- foo
-
-
- bar
- ```
-.
-<ul>
-<li>
-<p>foo</p>
-<p>bar</p>
-</li>
-<li>
-<p>foo</p>
-</li>
-</ul>
-<p>bar</p>
-<ul>
-<li>
-<pre><code>foo
-
-
-bar
-</code></pre>
-</li>
-<li>
-<p>baz</p>
-<ul>
-<li>
-<pre><code>foo
-
-
-bar
-</code></pre>
-</li>
-</ul>
-</li>
-</ul>
-````````````````````````````````
-
-
-A list item may contain any kind of block:
-
-```````````````````````````````` example
-1. foo
-
- ```
- bar
- ```
-
- baz
-
- > bam
-.
-<ol>
-<li>
-<p>foo</p>
-<pre><code>bar
-</code></pre>
-<p>baz</p>
-<blockquote>
-<p>bam</p>
-</blockquote>
-</li>
-</ol>
-````````````````````````````````
-
-
-A list item that contains an indented code block will preserve
-empty lines within the code block verbatim, unless there are two
-or more empty lines in a row (since as described above, two
-blank lines end the list):
-
-```````````````````````````````` example
-- Foo
-
- bar
-
- baz
-.
-<ul>
-<li>
-<p>Foo</p>
-<pre><code>bar
-
-baz
-</code></pre>
-</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- Foo
-
- bar
-
-
- baz
-.
-<ul>
-<li>
-<p>Foo</p>
-<pre><code>bar
-</code></pre>
-</li>
-</ul>
-<pre><code> baz
-</code></pre>
-````````````````````````````````
-
-
-Note that ordered list start numbers must be nine digits or less:
-
-```````````````````````````````` example
-123456789. ok
-.
-<ol start="123456789">
-<li>ok</li>
-</ol>
-````````````````````````````````
-
-
-```````````````````````````````` example
-1234567890. not ok
-.
-<p>1234567890. not ok</p>
-````````````````````````````````
-
-
-A start number may begin with 0s:
-
-```````````````````````````````` example
-0. ok
-.
-<ol start="0">
-<li>ok</li>
-</ol>
-````````````````````````````````
-
-
-```````````````````````````````` example
-003. ok
-.
-<ol start="3">
-<li>ok</li>
-</ol>
-````````````````````````````````
-
-
-A start number may not be negative:
-
-```````````````````````````````` example
--1. not ok
-.
-<p>-1. not ok</p>
-````````````````````````````````
-
-
-
-2. **Item starting with indented code.** If a sequence of lines *Ls*
- constitute a sequence of blocks *Bs* starting with an indented code
- block and not separated from each other by more than one blank line,
- and *M* is a list marker of width *W* followed by
- one space, then the result of prepending *M* and the following
- space to the first line of *Ls*, and indenting subsequent lines of
- *Ls* by *W + 1* spaces, is a list item with *Bs* as its contents.
- If a line is empty, then it need not be indented. The type of the
- list item (bullet or ordered) is determined by the type of its list
- marker. If the list item is ordered, then it is also assigned a
- start number, based on the ordered list marker.
-
-An indented code block will have to be indented four spaces beyond
-the edge of the region where text will be included in the list item.
-In the following case that is 6 spaces:
-
-```````````````````````````````` example
-- foo
-
- bar
-.
-<ul>
-<li>
-<p>foo</p>
-<pre><code>bar
-</code></pre>
-</li>
-</ul>
-````````````````````````````````
-
-
-And in this case it is 11 spaces:
-
-```````````````````````````````` example
- 10. foo
-
- bar
-.
-<ol start="10">
-<li>
-<p>foo</p>
-<pre><code>bar
-</code></pre>
-</li>
-</ol>
-````````````````````````````````
-
-
-If the *first* block in the list item is an indented code block,
-then by rule #2, the contents must be indented *one* space after the
-list marker:
-
-```````````````````````````````` example
- indented code
-
-paragraph
-
- more code
-.
-<pre><code>indented code
-</code></pre>
-<p>paragraph</p>
-<pre><code>more code
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-1. indented code
-
- paragraph
-
- more code
-.
-<ol>
-<li>
-<pre><code>indented code
-</code></pre>
-<p>paragraph</p>
-<pre><code>more code
-</code></pre>
-</li>
-</ol>
-````````````````````````````````
-
-
-Note that an additional space indent is interpreted as space
-inside the code block:
-
-```````````````````````````````` example
-1. indented code
-
- paragraph
-
- more code
-.
-<ol>
-<li>
-<pre><code> indented code
-</code></pre>
-<p>paragraph</p>
-<pre><code>more code
-</code></pre>
-</li>
-</ol>
-````````````````````````````````
-
-
-Note that rules #1 and #2 only apply to two cases: (a) cases
-in which the lines to be included in a list item begin with a
-[non-whitespace character], and (b) cases in which
-they begin with an indented code
-block. In a case like the following, where the first block begins with
-a three-space indent, the rules do not allow us to form a list item by
-indenting the whole thing and prepending a list marker:
-
-```````````````````````````````` example
- foo
-
-bar
-.
-<p>foo</p>
-<p>bar</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- foo
-
- bar
-.
-<ul>
-<li>foo</li>
-</ul>
-<p>bar</p>
-````````````````````````````````
-
-
-This is not a significant restriction, because when a block begins
-with 1-3 spaces indent, the indentation can always be removed without
-a change in interpretation, allowing rule #1 to be applied. So, in
-the above case:
-
-```````````````````````````````` example
-- foo
-
- bar
-.
-<ul>
-<li>
-<p>foo</p>
-<p>bar</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-3. **Item starting with a blank line.** If a sequence of lines *Ls*
- starting with a single [blank line] constitute a (possibly empty)
- sequence of blocks *Bs*, not separated from each other by more than
- one blank line, and *M* is a list marker of width *W*,
- then the result of prepending *M* to the first line of *Ls*, and
- indenting subsequent lines of *Ls* by *W + 1* spaces, is a list
- item with *Bs* as its contents.
- If a line is empty, then it need not be indented. The type of the
- list item (bullet or ordered) is determined by the type of its list
- marker. If the list item is ordered, then it is also assigned a
- start number, based on the ordered list marker.
-
-Here are some list items that start with a blank line but are not empty:
-
-```````````````````````````````` example
--
- foo
--
- ```
- bar
- ```
--
- baz
-.
-<ul>
-<li>foo</li>
-<li>
-<pre><code>bar
-</code></pre>
-</li>
-<li>
-<pre><code>baz
-</code></pre>
-</li>
-</ul>
-````````````````````````````````
-
-When the list item starts with a blank line, the number of spaces
-following the list marker doesn't change the required indentation:
-
-```````````````````````````````` example
--
- foo
-.
-<ul>
-<li>foo</li>
-</ul>
-````````````````````````````````
-
-
-A list item can begin with at most one blank line.
-In the following example, `foo` is not part of the list
-item:
-
-```````````````````````````````` example
--
-
- foo
-.
-<ul>
-<li></li>
-</ul>
-<p>foo</p>
-````````````````````````````````
-
-
-Here is an empty bullet list item:
-
-```````````````````````````````` example
-- foo
--
-- bar
-.
-<ul>
-<li>foo</li>
-<li></li>
-<li>bar</li>
-</ul>
-````````````````````````````````
-
-
-It does not matter whether there are spaces following the [list marker]:
-
-```````````````````````````````` example
-- foo
--
-- bar
-.
-<ul>
-<li>foo</li>
-<li></li>
-<li>bar</li>
-</ul>
-````````````````````````````````
-
-
-Here is an empty ordered list item:
-
-```````````````````````````````` example
-1. foo
-2.
-3. bar
-.
-<ol>
-<li>foo</li>
-<li></li>
-<li>bar</li>
-</ol>
-````````````````````````````````
-
-
-A list may start or end with an empty list item:
-
-```````````````````````````````` example
-*
-.
-<ul>
-<li></li>
-</ul>
-````````````````````````````````
-
-
-
-4. **Indentation.** If a sequence of lines *Ls* constitutes a list item
- according to rule #1, #2, or #3, then the result of indenting each line
- of *Ls* by 1-3 spaces (the same for each line) also constitutes a
- list item with the same contents and attributes. If a line is
- empty, then it need not be indented.
-
-Indented one space:
-
-```````````````````````````````` example
- 1. A paragraph
- with two lines.
-
- indented code
-
- > A block quote.
-.
-<ol>
-<li>
-<p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote>
-</li>
-</ol>
-````````````````````````````````
-
-
-Indented two spaces:
-
-```````````````````````````````` example
- 1. A paragraph
- with two lines.
-
- indented code
-
- > A block quote.
-.
-<ol>
-<li>
-<p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote>
-</li>
-</ol>
-````````````````````````````````
-
-
-Indented three spaces:
-
-```````````````````````````````` example
- 1. A paragraph
- with two lines.
-
- indented code
-
- > A block quote.
-.
-<ol>
-<li>
-<p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote>
-</li>
-</ol>
-````````````````````````````````
-
-
-Four spaces indent gives a code block:
-
-```````````````````````````````` example
- 1. A paragraph
- with two lines.
-
- indented code
-
- > A block quote.
-.
-<pre><code>1. A paragraph
- with two lines.
-
- indented code
-
- > A block quote.
-</code></pre>
-````````````````````````````````
-
-
-
-5. **Laziness.** If a string of lines *Ls* constitute a [list
- item](#list-items) with contents *Bs*, then the result of deleting
- some or all of the indentation from one or more lines in which the
- next [non-whitespace character] after the indentation is
- [paragraph continuation text] is a
- list item with the same contents and attributes. The unindented
- lines are called
- [lazy continuation line](@)s.
-
-Here is an example with [lazy continuation lines]:
-
-```````````````````````````````` example
- 1. A paragraph
-with two lines.
-
- indented code
-
- > A block quote.
-.
-<ol>
-<li>
-<p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote>
-</li>
-</ol>
-````````````````````````````````
-
-
-Indentation can be partially deleted:
-
-```````````````````````````````` example
- 1. A paragraph
- with two lines.
-.
-<ol>
-<li>A paragraph
-with two lines.</li>
-</ol>
-````````````````````````````````
-
-
-These examples show how laziness can work in nested structures:
-
-```````````````````````````````` example
-> 1. > Blockquote
-continued here.
-.
-<blockquote>
-<ol>
-<li>
-<blockquote>
-<p>Blockquote
-continued here.</p>
-</blockquote>
-</li>
-</ol>
-</blockquote>
-````````````````````````````````
-
-
-```````````````````````````````` example
-> 1. > Blockquote
-> continued here.
-.
-<blockquote>
-<ol>
-<li>
-<blockquote>
-<p>Blockquote
-continued here.</p>
-</blockquote>
-</li>
-</ol>
-</blockquote>
-````````````````````````````````
-
-
-
-6. **That's all.** Nothing that is not counted as a list item by rules
- #1--5 counts as a [list item](#list-items).
-
-The rules for sublists follow from the general rules above. A sublist
-must be indented the same number of spaces a paragraph would need to be
-in order to be included in the list item.
-
-So, in this case we need two spaces indent:
-
-```````````````````````````````` example
-- foo
- - bar
- - baz
-.
-<ul>
-<li>foo
-<ul>
-<li>bar
-<ul>
-<li>baz</li>
-</ul>
-</li>
-</ul>
-</li>
-</ul>
-````````````````````````````````
-
-
-One is not enough:
-
-```````````````````````````````` example
-- foo
- - bar
- - baz
-.
-<ul>
-<li>foo</li>
-<li>bar</li>
-<li>baz</li>
-</ul>
-````````````````````````````````
-
-
-Here we need four, because the list marker is wider:
-
-```````````````````````````````` example
-10) foo
- - bar
-.
-<ol start="10">
-<li>foo
-<ul>
-<li>bar</li>
-</ul>
-</li>
-</ol>
-````````````````````````````````
-
-
-Three is not enough:
-
-```````````````````````````````` example
-10) foo
- - bar
-.
-<ol start="10">
-<li>foo</li>
-</ol>
-<ul>
-<li>bar</li>
-</ul>
-````````````````````````````````
-
-
-A list may be the first block in a list item:
-
-```````````````````````````````` example
-- - foo
-.
-<ul>
-<li>
-<ul>
-<li>foo</li>
-</ul>
-</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-1. - 2. foo
-.
-<ol>
-<li>
-<ul>
-<li>
-<ol start="2">
-<li>foo</li>
-</ol>
-</li>
-</ul>
-</li>
-</ol>
-````````````````````````````````
-
-
-A list item can contain a heading:
-
-```````````````````````````````` example
-- # Foo
-- Bar
- ---
- baz
-.
-<ul>
-<li>
-<h1>Foo</h1>
-</li>
-<li>
-<h2>Bar</h2>
-baz</li>
-</ul>
-````````````````````````````````
-
-
-### Motivation
-
-John Gruber's Markdown spec says the following about list items:
-
-1. "List markers typically start at the left margin, but may be indented
- by up to three spaces. List markers must be followed by one or more
- spaces or a tab."
-
-2. "To make lists look nice, you can wrap items with hanging indents....
- But if you don't want to, you don't have to."
-
-3. "List items may consist of multiple paragraphs. Each subsequent
- paragraph in a list item must be indented by either 4 spaces or one
- tab."
-
-4. "It looks nice if you indent every line of the subsequent paragraphs,
- but here again, Markdown will allow you to be lazy."
-
-5. "To put a blockquote within a list item, the blockquote's `>`
- delimiters need to be indented."
-
-6. "To put a code block within a list item, the code block needs to be
- indented twice — 8 spaces or two tabs."
-
-These rules specify that a paragraph under a list item must be indented
-four spaces (presumably, from the left margin, rather than the start of
-the list marker, but this is not said), and that code under a list item
-must be indented eight spaces instead of the usual four. They also say
-that a block quote must be indented, but not by how much; however, the
-example given has four spaces indentation. Although nothing is said
-about other kinds of block-level content, it is certainly reasonable to
-infer that *all* block elements under a list item, including other
-lists, must be indented four spaces. This principle has been called the
-*four-space rule*.
-
-The four-space rule is clear and principled, and if the reference
-implementation `Markdown.pl` had followed it, it probably would have
-become the standard. However, `Markdown.pl` allowed paragraphs and
-sublists to start with only two spaces indentation, at least on the
-outer level. Worse, its behavior was inconsistent: a sublist of an
-outer-level list needed two spaces indentation, but a sublist of this
-sublist needed three spaces. It is not surprising, then, that different
-implementations of Markdown have developed very different rules for
-determining what comes under a list item. (Pandoc and python-Markdown,
-for example, stuck with Gruber's syntax description and the four-space
-rule, while discount, redcarpet, marked, PHP Markdown, and others
-followed `Markdown.pl`'s behavior more closely.)
-
-Unfortunately, given the divergences between implementations, there
-is no way to give a spec for list items that will be guaranteed not
-to break any existing documents. However, the spec given here should
-correctly handle lists formatted with either the four-space rule or
-the more forgiving `Markdown.pl` behavior, provided they are laid out
-in a way that is natural for a human to read.
-
-The strategy here is to let the width and indentation of the list marker
-determine the indentation necessary for blocks to fall under the list
-item, rather than having a fixed and arbitrary number. The writer can
-think of the body of the list item as a unit which gets indented to the
-right enough to fit the list marker (and any indentation on the list
-marker). (The laziness rule, #5, then allows continuation lines to be
-unindented if needed.)
-
-This rule is superior, we claim, to any rule requiring a fixed level of
-indentation from the margin. The four-space rule is clear but
-unnatural. It is quite unintuitive that
-
-``` markdown
-- foo
-
- bar
-
- - baz
-```
-
-should be parsed as two lists with an intervening paragraph,
-
-``` html
-<ul>
-<li>foo</li>
-</ul>
-<p>bar</p>
-<ul>
-<li>baz</li>
-</ul>
-```
-
-as the four-space rule demands, rather than a single list,
-
-``` html
-<ul>
-<li>
-<p>foo</p>
-<p>bar</p>
-<ul>
-<li>baz</li>
-</ul>
-</li>
-</ul>
-```
-
-The choice of four spaces is arbitrary. It can be learned, but it is
-not likely to be guessed, and it trips up beginners regularly.
-
-Would it help to adopt a two-space rule? The problem is that such
-a rule, together with the rule allowing 1--3 spaces indentation of the
-initial list marker, allows text that is indented *less than* the
-original list marker to be included in the list item. For example,
-`Markdown.pl` parses
-
-``` markdown
- - one
-
- two
-```
-
-as a single list item, with `two` a continuation paragraph:
-
-``` html
-<ul>
-<li>
-<p>one</p>
-<p>two</p>
-</li>
-</ul>
-```
-
-and similarly
-
-``` markdown
-> - one
->
-> two
-```
-
-as
-
-``` html
-<blockquote>
-<ul>
-<li>
-<p>one</p>
-<p>two</p>
-</li>
-</ul>
-</blockquote>
-```
-
-This is extremely unintuitive.
-
-Rather than requiring a fixed indent from the margin, we could require
-a fixed indent (say, two spaces, or even one space) from the list marker (which
-may itself be indented). This proposal would remove the last anomaly
-discussed. Unlike the spec presented above, it would count the following
-as a list item with a subparagraph, even though the paragraph `bar`
-is not indented as far as the first paragraph `foo`:
-
-``` markdown
- 10. foo
-
- bar
-```
-
-Arguably this text does read like a list item with `bar` as a subparagraph,
-which may count in favor of the proposal. However, on this proposal indented
-code would have to be indented six spaces after the list marker. And this
-would break a lot of existing Markdown, which has the pattern:
-
-``` markdown
-1. foo
-
- indented code
-```
-
-where the code is indented eight spaces. The spec above, by contrast, will
-parse this text as expected, since the code block's indentation is measured
-from the beginning of `foo`.
-
-The one case that needs special treatment is a list item that *starts*
-with indented code. How much indentation is required in that case, since
-we don't have a "first paragraph" to measure from? Rule #2 simply stipulates
-that in such cases, we require one space indentation from the list marker
-(and then the normal four spaces for the indented code). This will match the
-four-space rule in cases where the list marker plus its initial indentation
-takes four spaces (a common case), but diverge in other cases.
-
-## Lists
-
-A [list](@) is a sequence of one or more
-list items [of the same type]. The list items
-may be separated by single [blank lines], but two
-blank lines end all containing lists.
-
-Two list items are [of the same type](@)
-if they begin with a [list marker] of the same type.
-Two list markers are of the
-same type if (a) they are bullet list markers using the same character
-(`-`, `+`, or `*`) or (b) they are ordered list numbers with the same
-delimiter (either `.` or `)`).
-
-A list is an [ordered list](@)
-if its constituent list items begin with
-[ordered list markers], and a
-[bullet list](@) if its constituent list
-items begin with [bullet list markers].
-
-The [start number](@)
-of an [ordered list] is determined by the list number of
-its initial list item. The numbers of subsequent list items are
-disregarded.
-
-A list is [loose](@) if any of its constituent
-list items are separated by blank lines, or if any of its constituent
-list items directly contain two block-level elements with a blank line
-between them. Otherwise a list is [tight](@).
-(The difference in HTML output is that paragraphs in a loose list are
-wrapped in `<p>` tags, while paragraphs in a tight list are not.)
-
-Changing the bullet or ordered list delimiter starts a new list:
-
-```````````````````````````````` example
-- foo
-- bar
-+ baz
-.
-<ul>
-<li>foo</li>
-<li>bar</li>
-</ul>
-<ul>
-<li>baz</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-1. foo
-2. bar
-3) baz
-.
-<ol>
-<li>foo</li>
-<li>bar</li>
-</ol>
-<ol start="3">
-<li>baz</li>
-</ol>
-````````````````````````````````
-
-
-In CommonMark, a list can interrupt a paragraph. That is,
-no blank line is needed to separate a paragraph from a following
-list:
-
-```````````````````````````````` example
-Foo
-- bar
-- baz
-.
-<p>Foo</p>
-<ul>
-<li>bar</li>
-<li>baz</li>
-</ul>
-````````````````````````````````
-
-
-`Markdown.pl` does not allow this, through fear of triggering a list
-via a numeral in a hard-wrapped line:
-
-```````````````````````````````` example
-The number of windows in my house is
-14. The number of doors is 6.
-.
-<p>The number of windows in my house is</p>
-<ol start="14">
-<li>The number of doors is 6.</li>
-</ol>
-````````````````````````````````
-
-
-Oddly, `Markdown.pl` *does* allow a blockquote to interrupt a paragraph,
-even though the same considerations might apply. We think that the two
-cases should be treated the same. Here are two reasons for allowing
-lists to interrupt paragraphs:
-
-First, it is natural and not uncommon for people to start lists without
-blank lines:
-
- I need to buy
- - new shoes
- - a coat
- - a plane ticket
-
-Second, we are attracted to a
-
-> [principle of uniformity](@):
-> if a chunk of text has a certain
-> meaning, it will continue to have the same meaning when put into a
-> container block (such as a list item or blockquote).
-
-(Indeed, the spec for [list items] and [block quotes] presupposes
-this principle.) This principle implies that if
-
- * I need to buy
- - new shoes
- - a coat
- - a plane ticket
-
-is a list item containing a paragraph followed by a nested sublist,
-as all Markdown implementations agree it is (though the paragraph
-may be rendered without `<p>` tags, since the list is "tight"),
-then
-
- I need to buy
- - new shoes
- - a coat
- - a plane ticket
-
-by itself should be a paragraph followed by a nested sublist.
-
-Our adherence to the [principle of uniformity]
-thus inclines us to think that there are two coherent packages:
-
-1. Require blank lines before *all* lists and blockquotes,
- including lists that occur as sublists inside other list items.
-
-2. Require blank lines in none of these places.
-
-[reStructuredText](http://docutils.sourceforge.net/rst.html) takes
-the first approach, for which there is much to be said. But the second
-seems more consistent with established practice with Markdown.
-
-There can be blank lines between items, but two blank lines end
-a list:
-
-```````````````````````````````` example
-- foo
-
-- bar
-
-
-- baz
-.
-<ul>
-<li>
-<p>foo</p>
-</li>
-<li>
-<p>bar</p>
-</li>
-</ul>
-<ul>
-<li>baz</li>
-</ul>
-````````````````````````````````
-
-
-As illustrated above in the section on [list items],
-two blank lines between blocks *within* a list item will also end a
-list:
-
-```````````````````````````````` example
-- foo
-
-
- bar
-- baz
-.
-<ul>
-<li>foo</li>
-</ul>
-<p>bar</p>
-<ul>
-<li>baz</li>
-</ul>
-````````````````````````````````
-
-
-Indeed, two blank lines will end *all* containing lists:
-
-```````````````````````````````` example
-- foo
- - bar
- - baz
-
-
- bim
-.
-<ul>
-<li>foo
-<ul>
-<li>bar
-<ul>
-<li>baz</li>
-</ul>
-</li>
-</ul>
-</li>
-</ul>
-<pre><code> bim
-</code></pre>
-````````````````````````````````
-
-
-Thus, two blank lines can be used to separate consecutive lists of
-the same type, or to separate a list from an indented code block
-that would otherwise be parsed as a subparagraph of the final list
-item:
-
-```````````````````````````````` example
-- foo
-- bar
-
-
-- baz
-- bim
-.
-<ul>
-<li>foo</li>
-<li>bar</li>
-</ul>
-<ul>
-<li>baz</li>
-<li>bim</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- foo
-
- notcode
-
-- foo
-
-
- code
-.
-<ul>
-<li>
-<p>foo</p>
-<p>notcode</p>
-</li>
-<li>
-<p>foo</p>
-</li>
-</ul>
-<pre><code>code
-</code></pre>
-````````````````````````````````
-
-
-List items need not be indented to the same level. The following
-list items will be treated as items at the same list level,
-since none is indented enough to belong to the previous list
-item:
-
-```````````````````````````````` example
-- a
- - b
- - c
- - d
- - e
- - f
- - g
- - h
-- i
-.
-<ul>
-<li>a</li>
-<li>b</li>
-<li>c</li>
-<li>d</li>
-<li>e</li>
-<li>f</li>
-<li>g</li>
-<li>h</li>
-<li>i</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-1. a
-
- 2. b
-
- 3. c
-.
-<ol>
-<li>
-<p>a</p>
-</li>
-<li>
-<p>b</p>
-</li>
-<li>
-<p>c</p>
-</li>
-</ol>
-````````````````````````````````
-
-
-This is a loose list, because there is a blank line between
-two of the list items:
-
-```````````````````````````````` example
-- a
-- b
-
-- c
-.
-<ul>
-<li>
-<p>a</p>
-</li>
-<li>
-<p>b</p>
-</li>
-<li>
-<p>c</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-So is this, with a empty second item:
-
-```````````````````````````````` example
-* a
-*
-
-* c
-.
-<ul>
-<li>
-<p>a</p>
-</li>
-<li></li>
-<li>
-<p>c</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-These are loose lists, even though there is no space between the items,
-because one of the items directly contains two block-level elements
-with a blank line between them:
-
-```````````````````````````````` example
-- a
-- b
-
- c
-- d
-.
-<ul>
-<li>
-<p>a</p>
-</li>
-<li>
-<p>b</p>
-<p>c</p>
-</li>
-<li>
-<p>d</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- a
-- b
-
- [ref]: /url
-- d
-.
-<ul>
-<li>
-<p>a</p>
-</li>
-<li>
-<p>b</p>
-</li>
-<li>
-<p>d</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-This is a tight list, because the blank lines are in a code block:
-
-```````````````````````````````` example
-- a
-- ```
- b
-
-
- ```
-- c
-.
-<ul>
-<li>a</li>
-<li>
-<pre><code>b
-
-
-</code></pre>
-</li>
-<li>c</li>
-</ul>
-````````````````````````````````
-
-
-This is a tight list, because the blank line is between two
-paragraphs of a sublist. So the sublist is loose while
-the outer list is tight:
-
-```````````````````````````````` example
-- a
- - b
-
- c
-- d
-.
-<ul>
-<li>a
-<ul>
-<li>
-<p>b</p>
-<p>c</p>
-</li>
-</ul>
-</li>
-<li>d</li>
-</ul>
-````````````````````````````````
-
-
-This is a tight list, because the blank line is inside the
-block quote:
-
-```````````````````````````````` example
-* a
- > b
- >
-* c
-.
-<ul>
-<li>a
-<blockquote>
-<p>b</p>
-</blockquote>
-</li>
-<li>c</li>
-</ul>
-````````````````````````````````
-
-
-This list is tight, because the consecutive block elements
-are not separated by blank lines:
-
-```````````````````````````````` example
-- a
- > b
- ```
- c
- ```
-- d
-.
-<ul>
-<li>a
-<blockquote>
-<p>b</p>
-</blockquote>
-<pre><code>c
-</code></pre>
-</li>
-<li>d</li>
-</ul>
-````````````````````````````````
-
-
-A single-paragraph list is tight:
-
-```````````````````````````````` example
-- a
-.
-<ul>
-<li>a</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- a
- - b
-.
-<ul>
-<li>a
-<ul>
-<li>b</li>
-</ul>
-</li>
-</ul>
-````````````````````````````````
-
-
-This list is loose, because of the blank line between the
-two block elements in the list item:
-
-```````````````````````````````` example
-1. ```
- foo
- ```
-
- bar
-.
-<ol>
-<li>
-<pre><code>foo
-</code></pre>
-<p>bar</p>
-</li>
-</ol>
-````````````````````````````````
-
-
-Here the outer list is loose, the inner list tight:
-
-```````````````````````````````` example
-* foo
- * bar
-
- baz
-.
-<ul>
-<li>
-<p>foo</p>
-<ul>
-<li>bar</li>
-</ul>
-<p>baz</p>
-</li>
-</ul>
-````````````````````````````````
-
-
-```````````````````````````````` example
-- a
- - b
- - c
-
-- d
- - e
- - f
-.
-<ul>
-<li>
-<p>a</p>
-<ul>
-<li>b</li>
-<li>c</li>
-</ul>
-</li>
-<li>
-<p>d</p>
-<ul>
-<li>e</li>
-<li>f</li>
-</ul>
-</li>
-</ul>
-````````````````````````````````
-
-
-# Inlines
-
-Inlines are parsed sequentially from the beginning of the character
-stream to the end (left to right, in left-to-right languages).
-Thus, for example, in
-
-```````````````````````````````` example
-`hi`lo`
-.
-<p><code>hi</code>lo`</p>
-````````````````````````````````
-
-
-`hi` is parsed as code, leaving the backtick at the end as a literal
-backtick.
-
-## Backslash escapes
-
-Any ASCII punctuation character may be backslash-escaped:
-
-```````````````````````````````` example
-\!\"\#\$\%\&\'\(\)\*\+\,\-\.\/\:\;\<\=\>\?\@\[\\\]\^\_\`\{\|\}\~
-.
-<p>!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~</p>
-````````````````````````````````
-
-
-Backslashes before other characters are treated as literal
-backslashes:
-
-```````````````````````````````` example
-\→\A\a\ \3\φ\«
-.
-<p>\→\A\a\ \3\φ\«</p>
-````````````````````````````````
-
-
-Escaped characters are treated as regular characters and do
-not have their usual Markdown meanings:
-
-```````````````````````````````` example
-\*not emphasized*
-\<br/> not a tag
-\[not a link](/foo)
-\`not code`
-1\. not a list
-\* not a list
-\# not a heading
-\[foo]: /url "not a reference"
-.
-<p>*not emphasized*
-<br/> not a tag
-[not a link](/foo)
-`not code`
-1. not a list
-* not a list
-# not a heading
-[foo]: /url "not a reference"</p>
-````````````````````````````````
-
-
-If a backslash is itself escaped, the following character is not:
-
-```````````````````````````````` example
-\\*emphasis*
-.
-<p>\<em>emphasis</em></p>
-````````````````````````````````
-
-
-A backslash at the end of the line is a [hard line break]:
-
-```````````````````````````````` example
-foo\
-bar
-.
-<p>foo<br />
-bar</p>
-````````````````````````````````
-
-
-Backslash escapes do not work in code blocks, code spans, autolinks, or
-raw HTML:
-
-```````````````````````````````` example
-`` \[\` ``
-.
-<p><code>\[\`</code></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
- \[\]
-.
-<pre><code>\[\]
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-~~~
-\[\]
-~~~
-.
-<pre><code>\[\]
-</code></pre>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<http://example.com?find=\*>
-.
-<p><a href="http://example.com?find=%5C*">http://example.com?find=\*</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<a href="/bar\/)">
-.
-<a href="/bar\/)">
-````````````````````````````````
-
-
-But they work in all other contexts, including URLs and link titles,
-link references, and [info strings] in [fenced code blocks]:
-
-```````````````````````````````` example
-[foo](/bar\* "ti\*tle")
-.
-<p><a href="/bar*" title="ti*tle">foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo]
-
-[foo]: /bar\* "ti\*tle"
-.
-<p><a href="/bar*" title="ti*tle">foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-``` foo\+bar
-foo
-```
-.
-<pre><code class="language-foo+bar">foo
-</code></pre>
-````````````````````````````````
-
-
-
-## Entity and numeric character references
-
-All valid HTML entity references and numeric character
-references, except those occuring in code blocks and code spans,
-are recognized as such and treated as equivalent to the
-corresponding Unicode characters. Conforming CommonMark parsers
-need not store information about whether a particular character
-was represented in the source using a Unicode character or
-an entity reference.
-
-[Entity references](@) consist of `&` + any of the valid
-HTML5 entity names + `;`. The
-document <https://html.spec.whatwg.org/multipage/entities.json>
-is used as an authoritative source for the valid entity
-references and their corresponding code points.
-
-```````````````````````````````` example
- & © Æ Ď
-¾ ℋ ⅆ
-∲ ≧̸
-.
-<p> & © Æ Ď
-¾ ℋ ⅆ
-∲ ≧̸</p>
-````````````````````````````````
-
-
-[Decimal numeric character
-references](@)
-consist of `&#` + a string of 1--8 arabic digits + `;`. A
-numeric character reference is parsed as the corresponding
-Unicode character. Invalid Unicode code points will be replaced by
-the REPLACEMENT CHARACTER (`U+FFFD`). For security reasons,
-the code point `U+0000` will also be replaced by `U+FFFD`.
-
-```````````````````````````````` example
-# Ӓ Ϡ � �
-.
-<p># Ӓ Ϡ � �</p>
-````````````````````````````````
-
-
-[Hexadecimal numeric character
-references](@) consist of `&#` +
-either `X` or `x` + a string of 1-8 hexadecimal digits + `;`.
-They too are parsed as the corresponding Unicode character (this
-time specified with a hexadecimal numeral instead of decimal).
-
-```````````````````````````````` example
-" ആ ಫ
-.
-<p>" ആ ಫ</p>
-````````````````````````````````
-
-
-Here are some nonentities:
-
-```````````````````````````````` example
-  &x; &#; &#x;
-&ThisIsNotDefined; &hi?;
-.
-<p>&nbsp &x; &#; &#x;
-&ThisIsNotDefined; &hi?;</p>
-````````````````````````````````
-
-
-Although HTML5 does accept some entity references
-without a trailing semicolon (such as `©`), these are not
-recognized here, because it makes the grammar too ambiguous:
-
-```````````````````````````````` example
-©
-.
-<p>&copy</p>
-````````````````````````````````
-
-
-Strings that are not on the list of HTML5 named entities are not
-recognized as entity references either:
-
-```````````````````````````````` example
-&MadeUpEntity;
-.
-<p>&MadeUpEntity;</p>
-````````````````````````````````
-
-
-Entity and numeric character references are recognized in any
-context besides code spans or code blocks, including
-URLs, [link titles], and [fenced code block][] [info strings]:
-
-```````````````````````````````` example
-<a href="öö.html">
-.
-<a href="öö.html">
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo](/föö "föö")
-.
-<p><a href="/f%C3%B6%C3%B6" title="föö">foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo]
-
-[foo]: /föö "föö"
-.
-<p><a href="/f%C3%B6%C3%B6" title="föö">foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-``` föö
-foo
-```
-.
-<pre><code class="language-föö">foo
-</code></pre>
-````````````````````````````````
-
-
-Entity and numeric character references are treated as literal
-text in code spans and code blocks:
-
-```````````````````````````````` example
-`föö`
-.
-<p><code>f&ouml;&ouml;</code></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
- föfö
-.
-<pre><code>f&ouml;f&ouml;
-</code></pre>
-````````````````````````````````
-
-
-## Code spans
-
-A [backtick string](@)
-is a string of one or more backtick characters (`` ` ``) that is neither
-preceded nor followed by a backtick.
-
-A [code span](@) begins with a backtick string and ends with
-a backtick string of equal length. The contents of the code span are
-the characters between the two backtick strings, with leading and
-trailing spaces and [line endings] removed, and
-[whitespace] collapsed to single spaces.
-
-This is a simple code span:
-
-```````````````````````````````` example
-`foo`
-.
-<p><code>foo</code></p>
-````````````````````````````````
-
-
-Here two backticks are used, because the code contains a backtick.
-This example also illustrates stripping of leading and trailing spaces:
-
-```````````````````````````````` example
-`` foo ` bar ``
-.
-<p><code>foo ` bar</code></p>
-````````````````````````````````
-
-
-This example shows the motivation for stripping leading and trailing
-spaces:
-
-```````````````````````````````` example
-` `` `
-.
-<p><code>``</code></p>
-````````````````````````````````
-
-
-[Line endings] are treated like spaces:
-
-```````````````````````````````` example
-``
-foo
-``
-.
-<p><code>foo</code></p>
-````````````````````````````````
-
-
-Interior spaces and [line endings] are collapsed into
-single spaces, just as they would be by a browser:
-
-```````````````````````````````` example
-`foo bar
- baz`
-.
-<p><code>foo bar baz</code></p>
-````````````````````````````````
-
-
-Q: Why not just leave the spaces, since browsers will collapse them
-anyway? A: Because we might be targeting a non-HTML format, and we
-shouldn't rely on HTML-specific rendering assumptions.
-
-(Existing implementations differ in their treatment of internal
-spaces and [line endings]. Some, including `Markdown.pl` and
-`showdown`, convert an internal [line ending] into a
-`<br />` tag. But this makes things difficult for those who like to
-hard-wrap their paragraphs, since a line break in the midst of a code
-span will cause an unintended line break in the output. Others just
-leave internal spaces as they are, which is fine if only HTML is being
-targeted.)
-
-```````````````````````````````` example
-`foo `` bar`
-.
-<p><code>foo `` bar</code></p>
-````````````````````````````````
-
-
-Note that backslash escapes do not work in code spans. All backslashes
-are treated literally:
-
-```````````````````````````````` example
-`foo\`bar`
-.
-<p><code>foo\</code>bar`</p>
-````````````````````````````````
-
-
-Backslash escapes are never needed, because one can always choose a
-string of *n* backtick characters as delimiters, where the code does
-not contain any strings of exactly *n* backtick characters.
-
-Code span backticks have higher precedence than any other inline
-constructs except HTML tags and autolinks. Thus, for example, this is
-not parsed as emphasized text, since the second `*` is part of a code
-span:
-
-```````````````````````````````` example
-*foo`*`
-.
-<p>*foo<code>*</code></p>
-````````````````````````````````
-
-
-And this is not parsed as a link:
-
-```````````````````````````````` example
-[not a `link](/foo`)
-.
-<p>[not a <code>link](/foo</code>)</p>
-````````````````````````````````
-
-
-Code spans, HTML tags, and autolinks have the same precedence.
-Thus, this is code:
-
-```````````````````````````````` example
-`<a href="`">`
-.
-<p><code><a href="</code>">`</p>
-````````````````````````````````
-
-
-But this is an HTML tag:
-
-```````````````````````````````` example
-<a href="`">`
-.
-<p><a href="`">`</p>
-````````````````````````````````
-
-
-And this is code:
-
-```````````````````````````````` example
-`<http://foo.bar.`baz>`
-.
-<p><code><http://foo.bar.</code>baz>`</p>
-````````````````````````````````
-
-
-But this is an autolink:
-
-```````````````````````````````` example
-<http://foo.bar.`baz>`
-.
-<p><a href="http://foo.bar.%60baz">http://foo.bar.`baz</a>`</p>
-````````````````````````````````
-
-
-When a backtick string is not closed by a matching backtick string,
-we just have literal backticks:
-
-```````````````````````````````` example
-```foo``
-.
-<p>```foo``</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-`foo
-.
-<p>`foo</p>
-````````````````````````````````
-
-
-## Emphasis and strong emphasis
-
-John Gruber's original [Markdown syntax
-description](http://daringfireball.net/projects/markdown/syntax#em) says:
-
-> Markdown treats asterisks (`*`) and underscores (`_`) as indicators of
-> emphasis. Text wrapped with one `*` or `_` will be wrapped with an HTML
-> `<em>` tag; double `*`'s or `_`'s will be wrapped with an HTML `<strong>`
-> tag.
-
-This is enough for most users, but these rules leave much undecided,
-especially when it comes to nested emphasis. The original
-`Markdown.pl` test suite makes it clear that triple `***` and
-`___` delimiters can be used for strong emphasis, and most
-implementations have also allowed the following patterns:
-
-``` markdown
-***strong emph***
-***strong** in emph*
-***emph* in strong**
-**in strong *emph***
-*in emph **strong***
-```
-
-The following patterns are less widely supported, but the intent
-is clear and they are useful (especially in contexts like bibliography
-entries):
-
-``` markdown
-*emph *with emph* in it*
-**strong **with strong** in it**
-```
-
-Many implementations have also restricted intraword emphasis to
-the `*` forms, to avoid unwanted emphasis in words containing
-internal underscores. (It is best practice to put these in code
-spans, but users often do not.)
-
-``` markdown
-internal emphasis: foo*bar*baz
-no emphasis: foo_bar_baz
-```
-
-The rules given below capture all of these patterns, while allowing
-for efficient parsing strategies that do not backtrack.
-
-First, some definitions. A [delimiter run](@) is either
-a sequence of one or more `*` characters that is not preceded or
-followed by a `*` character, or a sequence of one or more `_`
-characters that is not preceded or followed by a `_` character.
-
-A [left-flanking delimiter run](@) is
-a [delimiter run] that is (a) not followed by [Unicode whitespace],
-and (b) either not followed by a [punctuation character], or
-preceded by [Unicode whitespace] or a [punctuation character].
-For purposes of this definition, the beginning and the end of
-the line count as Unicode whitespace.
-
-A [right-flanking delimiter run](@) is
-a [delimiter run] that is (a) not preceded by [Unicode whitespace],
-and (b) either not preceded by a [punctuation character], or
-followed by [Unicode whitespace] or a [punctuation character].
-For purposes of this definition, the beginning and the end of
-the line count as Unicode whitespace.
-
-Here are some examples of delimiter runs.
-
- - left-flanking but not right-flanking:
-
- ```
- ***abc
- _abc
- **"abc"
- _"abc"
- ```
-
- - right-flanking but not left-flanking:
-
- ```
- abc***
- abc_
- "abc"**
- "abc"_
- ```
-
- - Both left and right-flanking:
-
- ```
- abc***def
- "abc"_"def"
- ```
-
- - Neither left nor right-flanking:
-
- ```
- abc *** def
- a _ b
- ```
-
-(The idea of distinguishing left-flanking and right-flanking
-delimiter runs based on the character before and the character
-after comes from Roopesh Chander's
-[vfmd](http://www.vfmd.org/vfmd-spec/specification/#procedure-for-identifying-emphasis-tags).
-vfmd uses the terminology "emphasis indicator string" instead of "delimiter
-run," and its rules for distinguishing left- and right-flanking runs
-are a bit more complex than the ones given here.)
-
-The following rules define emphasis and strong emphasis:
-
-1. A single `*` character [can open emphasis](@)
- iff (if and only if) it is part of a [left-flanking delimiter run].
-
-2. A single `_` character [can open emphasis] iff
- it is part of a [left-flanking delimiter run]
- and either (a) not part of a [right-flanking delimiter run]
- or (b) part of a [right-flanking delimiter run]
- preceded by punctuation.
-
-3. A single `*` character [can close emphasis](@)
- iff it is part of a [right-flanking delimiter run].
-
-4. A single `_` character [can close emphasis] iff
- it is part of a [right-flanking delimiter run]
- and either (a) not part of a [left-flanking delimiter run]
- or (b) part of a [left-flanking delimiter run]
- followed by punctuation.
-
-5. A double `**` [can open strong emphasis](@)
- iff it is part of a [left-flanking delimiter run].
-
-6. A double `__` [can open strong emphasis] iff
- it is part of a [left-flanking delimiter run]
- and either (a) not part of a [right-flanking delimiter run]
- or (b) part of a [right-flanking delimiter run]
- preceded by punctuation.
-
-7. A double `**` [can close strong emphasis](@)
- iff it is part of a [right-flanking delimiter run].
-
-8. A double `__` [can close strong emphasis]
- it is part of a [right-flanking delimiter run]
- and either (a) not part of a [left-flanking delimiter run]
- or (b) part of a [left-flanking delimiter run]
- followed by punctuation.
-
-9. Emphasis begins with a delimiter that [can open emphasis] and ends
- with a delimiter that [can close emphasis], and that uses the same
- character (`_` or `*`) as the opening delimiter. There must
- be a nonempty sequence of inlines between the open delimiter
- and the closing delimiter; these form the contents of the emphasis
- inline.
-
-10. Strong emphasis begins with a delimiter that
- [can open strong emphasis] and ends with a delimiter that
- [can close strong emphasis], and that uses the same character
- (`_` or `*`) as the opening delimiter.
- There must be a nonempty sequence of inlines between the open
- delimiter and the closing delimiter; these form the contents of
- the strong emphasis inline.
-
-11. A literal `*` character cannot occur at the beginning or end of
- `*`-delimited emphasis or `**`-delimited strong emphasis, unless it
- is backslash-escaped.
-
-12. A literal `_` character cannot occur at the beginning or end of
- `_`-delimited emphasis or `__`-delimited strong emphasis, unless it
- is backslash-escaped.
-
-Where rules 1--12 above are compatible with multiple parsings,
-the following principles resolve ambiguity:
-
-13. The number of nestings should be minimized. Thus, for example,
- an interpretation `<strong>...</strong>` is always preferred to
- `<em><em>...</em></em>`.
-
-14. An interpretation `<strong><em>...</em></strong>` is always
- preferred to `<em><strong>..</strong></em>`.
-
-15. When two potential emphasis or strong emphasis spans overlap,
- so that the second begins before the first ends and ends after
- the first ends, the first takes precedence. Thus, for example,
- `*foo _bar* baz_` is parsed as `<em>foo _bar</em> baz_` rather
- than `*foo <em>bar* baz</em>`. For the same reason,
- `**foo*bar**` is parsed as `<em><em>foo</em>bar</em>*`
- rather than `<strong>foo*bar</strong>`.
-
-16. When there are two potential emphasis or strong emphasis spans
- with the same closing delimiter, the shorter one (the one that
- opens later) takes precedence. Thus, for example,
- `**foo **bar baz**` is parsed as `**foo <strong>bar baz</strong>`
- rather than `<strong>foo **bar baz</strong>`.
-
-17. Inline code spans, links, images, and HTML tags group more tightly
- than emphasis. So, when there is a choice between an interpretation
- that contains one of these elements and one that does not, the
- former always wins. Thus, for example, `*[foo*](bar)` is
- parsed as `*<a href="bar">foo*</a>` rather than as
- `<em>[foo</em>](bar)`.
-
-These rules can be illustrated through a series of examples.
-
-Rule 1:
-
-```````````````````````````````` example
-*foo bar*
-.
-<p><em>foo bar</em></p>
-````````````````````````````````
-
-
-This is not emphasis, because the opening `*` is followed by
-whitespace, and hence not part of a [left-flanking delimiter run]:
-
-```````````````````````````````` example
-a * foo bar*
-.
-<p>a * foo bar*</p>
-````````````````````````````````
-
-
-This is not emphasis, because the opening `*` is preceded
-by an alphanumeric and followed by punctuation, and hence
-not part of a [left-flanking delimiter run]:
-
-```````````````````````````````` example
-a*"foo"*
-.
-<p>a*"foo"*</p>
-````````````````````````````````
-
-
-Unicode nonbreaking spaces count as whitespace, too:
-
-```````````````````````````````` example
-* a *
-.
-<p>* a *</p>
-````````````````````````````````
-
-
-Intraword emphasis with `*` is permitted:
-
-```````````````````````````````` example
-foo*bar*
-.
-<p>foo<em>bar</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-5*6*78
-.
-<p>5<em>6</em>78</p>
-````````````````````````````````
-
-
-Rule 2:
-
-```````````````````````````````` example
-_foo bar_
-.
-<p><em>foo bar</em></p>
-````````````````````````````````
-
-
-This is not emphasis, because the opening `_` is followed by
-whitespace:
-
-```````````````````````````````` example
-_ foo bar_
-.
-<p>_ foo bar_</p>
-````````````````````````````````
-
-
-This is not emphasis, because the opening `_` is preceded
-by an alphanumeric and followed by punctuation:
-
-```````````````````````````````` example
-a_"foo"_
-.
-<p>a_"foo"_</p>
-````````````````````````````````
-
-
-Emphasis with `_` is not allowed inside words:
-
-```````````````````````````````` example
-foo_bar_
-.
-<p>foo_bar_</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-5_6_78
-.
-<p>5_6_78</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-пристаням_стремятся_
-.
-<p>пристаням_стремятся_</p>
-````````````````````````````````
-
-
-Here `_` does not generate emphasis, because the first delimiter run
-is right-flanking and the second left-flanking:
-
-```````````````````````````````` example
-aa_"bb"_cc
-.
-<p>aa_"bb"_cc</p>
-````````````````````````````````
-
-
-This is emphasis, even though the opening delimiter is
-both left- and right-flanking, because it is preceded by
-punctuation:
-
-```````````````````````````````` example
-foo-_(bar)_
-.
-<p>foo-<em>(bar)</em></p>
-````````````````````````````````
-
-
-Rule 3:
-
-This is not emphasis, because the closing delimiter does
-not match the opening delimiter:
-
-```````````````````````````````` example
-_foo*
-.
-<p>_foo*</p>
-````````````````````````````````
-
-
-This is not emphasis, because the closing `*` is preceded by
-whitespace:
-
-```````````````````````````````` example
-*foo bar *
-.
-<p>*foo bar *</p>
-````````````````````````````````
-
-
-A newline also counts as whitespace:
-
-```````````````````````````````` example
-*foo bar
-*
-.
-<p>*foo bar</p>
-<ul>
-<li></li>
-</ul>
-````````````````````````````````
-
-
-This is not emphasis, because the second `*` is
-preceded by punctuation and followed by an alphanumeric
-(hence it is not part of a [right-flanking delimiter run]:
-
-```````````````````````````````` example
-*(*foo)
-.
-<p>*(*foo)</p>
-````````````````````````````````
-
-
-The point of this restriction is more easily appreciated
-with this example:
-
-```````````````````````````````` example
-*(*foo*)*
-.
-<p><em>(<em>foo</em>)</em></p>
-````````````````````````````````
-
-
-Intraword emphasis with `*` is allowed:
-
-```````````````````````````````` example
-*foo*bar
-.
-<p><em>foo</em>bar</p>
-````````````````````````````````
-
-
-
-Rule 4:
-
-This is not emphasis, because the closing `_` is preceded by
-whitespace:
-
-```````````````````````````````` example
-_foo bar _
-.
-<p>_foo bar _</p>
-````````````````````````````````
-
-
-This is not emphasis, because the second `_` is
-preceded by punctuation and followed by an alphanumeric:
-
-```````````````````````````````` example
-_(_foo)
-.
-<p>_(_foo)</p>
-````````````````````````````````
-
-
-This is emphasis within emphasis:
-
-```````````````````````````````` example
-_(_foo_)_
-.
-<p><em>(<em>foo</em>)</em></p>
-````````````````````````````````
-
-
-Intraword emphasis is disallowed for `_`:
-
-```````````````````````````````` example
-_foo_bar
-.
-<p>_foo_bar</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-_пристаням_стремятся
-.
-<p>_пристаням_стремятся</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-_foo_bar_baz_
-.
-<p><em>foo_bar_baz</em></p>
-````````````````````````````````
-
-
-This is emphasis, even though the closing delimiter is
-both left- and right-flanking, because it is followed by
-punctuation:
-
-```````````````````````````````` example
-_(bar)_.
-.
-<p><em>(bar)</em>.</p>
-````````````````````````````````
-
-
-Rule 5:
-
-```````````````````````````````` example
-**foo bar**
-.
-<p><strong>foo bar</strong></p>
-````````````````````````````````
-
-
-This is not strong emphasis, because the opening delimiter is
-followed by whitespace:
-
-```````````````````````````````` example
-** foo bar**
-.
-<p>** foo bar**</p>
-````````````````````````````````
-
-
-This is not strong emphasis, because the opening `**` is preceded
-by an alphanumeric and followed by punctuation, and hence
-not part of a [left-flanking delimiter run]:
-
-```````````````````````````````` example
-a**"foo"**
-.
-<p>a**"foo"**</p>
-````````````````````````````````
-
-
-Intraword strong emphasis with `**` is permitted:
-
-```````````````````````````````` example
-foo**bar**
-.
-<p>foo<strong>bar</strong></p>
-````````````````````````````````
-
-
-Rule 6:
-
-```````````````````````````````` example
-__foo bar__
-.
-<p><strong>foo bar</strong></p>
-````````````````````````````````
-
-
-This is not strong emphasis, because the opening delimiter is
-followed by whitespace:
-
-```````````````````````````````` example
-__ foo bar__
-.
-<p>__ foo bar__</p>
-````````````````````````````````
-
-
-A newline counts as whitespace:
-```````````````````````````````` example
-__
-foo bar__
-.
-<p>__
-foo bar__</p>
-````````````````````````````````
-
-
-This is not strong emphasis, because the opening `__` is preceded
-by an alphanumeric and followed by punctuation:
-
-```````````````````````````````` example
-a__"foo"__
-.
-<p>a__"foo"__</p>
-````````````````````````````````
-
-
-Intraword strong emphasis is forbidden with `__`:
-
-```````````````````````````````` example
-foo__bar__
-.
-<p>foo__bar__</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-5__6__78
-.
-<p>5__6__78</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-пристаням__стремятся__
-.
-<p>пристаням__стремятся__</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__foo, __bar__, baz__
-.
-<p><strong>foo, <strong>bar</strong>, baz</strong></p>
-````````````````````````````````
-
-
-This is strong emphasis, even though the opening delimiter is
-both left- and right-flanking, because it is preceded by
-punctuation:
-
-```````````````````````````````` example
-foo-__(bar)__
-.
-<p>foo-<strong>(bar)</strong></p>
-````````````````````````````````
-
-
-
-Rule 7:
-
-This is not strong emphasis, because the closing delimiter is preceded
-by whitespace:
-
-```````````````````````````````` example
-**foo bar **
-.
-<p>**foo bar **</p>
-````````````````````````````````
-
-
-(Nor can it be interpreted as an emphasized `*foo bar *`, because of
-Rule 11.)
-
-This is not strong emphasis, because the second `**` is
-preceded by punctuation and followed by an alphanumeric:
-
-```````````````````````````````` example
-**(**foo)
-.
-<p>**(**foo)</p>
-````````````````````````````````
-
-
-The point of this restriction is more easily appreciated
-with these examples:
-
-```````````````````````````````` example
-*(**foo**)*
-.
-<p><em>(<strong>foo</strong>)</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**Gomphocarpus (*Gomphocarpus physocarpus*, syn.
-*Asclepias physocarpa*)**
-.
-<p><strong>Gomphocarpus (<em>Gomphocarpus physocarpus</em>, syn.
-<em>Asclepias physocarpa</em>)</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**foo "*bar*" foo**
-.
-<p><strong>foo "<em>bar</em>" foo</strong></p>
-````````````````````````````````
-
-
-Intraword emphasis:
-
-```````````````````````````````` example
-**foo**bar
-.
-<p><strong>foo</strong>bar</p>
-````````````````````````````````
-
-
-Rule 8:
-
-This is not strong emphasis, because the closing delimiter is
-preceded by whitespace:
-
-```````````````````````````````` example
-__foo bar __
-.
-<p>__foo bar __</p>
-````````````````````````````````
-
-
-This is not strong emphasis, because the second `__` is
-preceded by punctuation and followed by an alphanumeric:
-
-```````````````````````````````` example
-__(__foo)
-.
-<p>__(__foo)</p>
-````````````````````````````````
-
-
-The point of this restriction is more easily appreciated
-with this example:
-
-```````````````````````````````` example
-_(__foo__)_
-.
-<p><em>(<strong>foo</strong>)</em></p>
-````````````````````````````````
-
-
-Intraword strong emphasis is forbidden with `__`:
-
-```````````````````````````````` example
-__foo__bar
-.
-<p>__foo__bar</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__пристаням__стремятся
-.
-<p>__пристаням__стремятся</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__foo__bar__baz__
-.
-<p><strong>foo__bar__baz</strong></p>
-````````````````````````````````
-
-
-This is strong emphasis, even though the closing delimiter is
-both left- and right-flanking, because it is followed by
-punctuation:
-
-```````````````````````````````` example
-__(bar)__.
-.
-<p><strong>(bar)</strong>.</p>
-````````````````````````````````
-
-
-Rule 9:
-
-Any nonempty sequence of inline elements can be the contents of an
-emphasized span.
-
-```````````````````````````````` example
-*foo [bar](/url)*
-.
-<p><em>foo <a href="/url">bar</a></em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo
-bar*
-.
-<p><em>foo
-bar</em></p>
-````````````````````````````````
-
-
-In particular, emphasis and strong emphasis can be nested
-inside emphasis:
-
-```````````````````````````````` example
-_foo __bar__ baz_
-.
-<p><em>foo <strong>bar</strong> baz</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-_foo _bar_ baz_
-.
-<p><em>foo <em>bar</em> baz</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__foo_ bar_
-.
-<p><em><em>foo</em> bar</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo *bar**
-.
-<p><em>foo <em>bar</em></em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo **bar** baz*
-.
-<p><em>foo <strong>bar</strong> baz</em></p>
-````````````````````````````````
-
-
-But note:
-
-```````````````````````````````` example
-*foo**bar**baz*
-.
-<p><em>foo</em><em>bar</em><em>baz</em></p>
-````````````````````````````````
-
-
-The difference is that in the preceding case, the internal delimiters
-[can close emphasis], while in the cases with spaces, they cannot.
-
-```````````````````````````````` example
-***foo** bar*
-.
-<p><em><strong>foo</strong> bar</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo **bar***
-.
-<p><em>foo <strong>bar</strong></em></p>
-````````````````````````````````
-
-
-Note, however, that in the following case we get no strong
-emphasis, because the opening delimiter is closed by the first
-`*` before `bar`:
-
-```````````````````````````````` example
-*foo**bar***
-.
-<p><em>foo</em><em>bar</em>**</p>
-````````````````````````````````
-
-
-
-Indefinite levels of nesting are possible:
-
-```````````````````````````````` example
-*foo **bar *baz* bim** bop*
-.
-<p><em>foo <strong>bar <em>baz</em> bim</strong> bop</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo [*bar*](/url)*
-.
-<p><em>foo <a href="/url"><em>bar</em></a></em></p>
-````````````````````````````````
-
-
-There can be no empty emphasis or strong emphasis:
-
-```````````````````````````````` example
-** is not an empty emphasis
-.
-<p>** is not an empty emphasis</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**** is not an empty strong emphasis
-.
-<p>**** is not an empty strong emphasis</p>
-````````````````````````````````
-
-
-
-Rule 10:
-
-Any nonempty sequence of inline elements can be the contents of an
-strongly emphasized span.
-
-```````````````````````````````` example
-**foo [bar](/url)**
-.
-<p><strong>foo <a href="/url">bar</a></strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**foo
-bar**
-.
-<p><strong>foo
-bar</strong></p>
-````````````````````````````````
-
-
-In particular, emphasis and strong emphasis can be nested
-inside strong emphasis:
-
-```````````````````````````````` example
-__foo _bar_ baz__
-.
-<p><strong>foo <em>bar</em> baz</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__foo __bar__ baz__
-.
-<p><strong>foo <strong>bar</strong> baz</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-____foo__ bar__
-.
-<p><strong><strong>foo</strong> bar</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**foo **bar****
-.
-<p><strong>foo <strong>bar</strong></strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**foo *bar* baz**
-.
-<p><strong>foo <em>bar</em> baz</strong></p>
-````````````````````````````````
-
-
-But note:
-
-```````````````````````````````` example
-**foo*bar*baz**
-.
-<p><em><em>foo</em>bar</em>baz**</p>
-````````````````````````````````
-
-
-The difference is that in the preceding case, the internal delimiters
-[can close emphasis], while in the cases with spaces, they cannot.
-
-```````````````````````````````` example
-***foo* bar**
-.
-<p><strong><em>foo</em> bar</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**foo *bar***
-.
-<p><strong>foo <em>bar</em></strong></p>
-````````````````````````````````
-
-
-Indefinite levels of nesting are possible:
-
-```````````````````````````````` example
-**foo *bar **baz**
-bim* bop**
-.
-<p><strong>foo <em>bar <strong>baz</strong>
-bim</em> bop</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**foo [*bar*](/url)**
-.
-<p><strong>foo <a href="/url"><em>bar</em></a></strong></p>
-````````````````````````````````
-
-
-There can be no empty emphasis or strong emphasis:
-
-```````````````````````````````` example
-__ is not an empty emphasis
-.
-<p>__ is not an empty emphasis</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-____ is not an empty strong emphasis
-.
-<p>____ is not an empty strong emphasis</p>
-````````````````````````````````
-
-
-
-Rule 11:
-
-```````````````````````````````` example
-foo ***
-.
-<p>foo ***</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo *\**
-.
-<p>foo <em>*</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo *_*
-.
-<p>foo <em>_</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo *****
-.
-<p>foo *****</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo **\***
-.
-<p>foo <strong>*</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo **_**
-.
-<p>foo <strong>_</strong></p>
-````````````````````````````````
-
-
-Note that when delimiters do not match evenly, Rule 11 determines
-that the excess literal `*` characters will appear outside of the
-emphasis, rather than inside it:
-
-```````````````````````````````` example
-**foo*
-.
-<p>*<em>foo</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo**
-.
-<p><em>foo</em>*</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-***foo**
-.
-<p>*<strong>foo</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-****foo*
-.
-<p>***<em>foo</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**foo***
-.
-<p><strong>foo</strong>*</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo****
-.
-<p><em>foo</em>***</p>
-````````````````````````````````
-
-
-
-Rule 12:
-
-```````````````````````````````` example
-foo ___
-.
-<p>foo ___</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo _\__
-.
-<p>foo <em>_</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo _*_
-.
-<p>foo <em>*</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo _____
-.
-<p>foo _____</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo __\___
-.
-<p>foo <strong>_</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo __*__
-.
-<p>foo <strong>*</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__foo_
-.
-<p>_<em>foo</em></p>
-````````````````````````````````
-
-
-Note that when delimiters do not match evenly, Rule 12 determines
-that the excess literal `_` characters will appear outside of the
-emphasis, rather than inside it:
-
-```````````````````````````````` example
-_foo__
-.
-<p><em>foo</em>_</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-___foo__
-.
-<p>_<strong>foo</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-____foo_
-.
-<p>___<em>foo</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__foo___
-.
-<p><strong>foo</strong>_</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-_foo____
-.
-<p><em>foo</em>___</p>
-````````````````````````````````
-
-
-Rule 13 implies that if you want emphasis nested directly inside
-emphasis, you must use different delimiters:
-
-```````````````````````````````` example
-**foo**
-.
-<p><strong>foo</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*_foo_*
-.
-<p><em><em>foo</em></em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__foo__
-.
-<p><strong>foo</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-_*foo*_
-.
-<p><em><em>foo</em></em></p>
-````````````````````````````````
-
-
-However, strong emphasis within strong emphasis is possible without
-switching delimiters:
-
-```````````````````````````````` example
-****foo****
-.
-<p><strong><strong>foo</strong></strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-____foo____
-.
-<p><strong><strong>foo</strong></strong></p>
-````````````````````````````````
-
-
-
-Rule 13 can be applied to arbitrarily long sequences of
-delimiters:
-
-```````````````````````````````` example
-******foo******
-.
-<p><strong><strong><strong>foo</strong></strong></strong></p>
-````````````````````````````````
-
-
-Rule 14:
-
-```````````````````````````````` example
-***foo***
-.
-<p><strong><em>foo</em></strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-_____foo_____
-.
-<p><strong><strong><em>foo</em></strong></strong></p>
-````````````````````````````````
-
-
-Rule 15:
-
-```````````````````````````````` example
-*foo _bar* baz_
-.
-<p><em>foo _bar</em> baz_</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**foo*bar**
-.
-<p><em><em>foo</em>bar</em>*</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo __bar *baz bim__ bam*
-.
-<p><em>foo <strong>bar *baz bim</strong> bam</em></p>
-````````````````````````````````
-
-
-Rule 16:
-
-```````````````````````````````` example
-**foo **bar baz**
-.
-<p>**foo <strong>bar baz</strong></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo *bar baz*
-.
-<p>*foo <em>bar baz</em></p>
-````````````````````````````````
-
-
-Rule 17:
-
-```````````````````````````````` example
-*[bar*](/url)
-.
-<p>*<a href="/url">bar*</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-_foo [bar_](/url)
-.
-<p>_foo <a href="/url">bar_</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*<img src="foo" title="*"/>
-.
-<p>*<img src="foo" title="*"/></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**<a href="**">
-.
-<p>**<a href="**"></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__<a href="__">
-.
-<p>__<a href="__"></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*a `*`*
-.
-<p><em>a <code>*</code></em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-_a `_`_
-.
-<p><em>a <code>_</code></em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-**a<http://foo.bar/?q=**>
-.
-<p>**a<a href="http://foo.bar/?q=**">http://foo.bar/?q=**</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-__a<http://foo.bar/?q=__>
-.
-<p>__a<a href="http://foo.bar/?q=__">http://foo.bar/?q=__</a></p>
-````````````````````````````````
-
-
-
-## Links
-
-A link contains [link text] (the visible text), a [link destination]
-(the URI that is the link destination), and optionally a [link title].
-There are two basic kinds of links in Markdown. In [inline links] the
-destination and title are given immediately after the link text. In
-[reference links] the destination and title are defined elsewhere in
-the document.
-
-A [link text](@) consists of a sequence of zero or more
-inline elements enclosed by square brackets (`[` and `]`). The
-following rules apply:
-
-- Links may not contain other links, at any level of nesting. If
- multiple otherwise valid link definitions appear nested inside each
- other, the inner-most definition is used.
-
-- Brackets are allowed in the [link text] only if (a) they
- are backslash-escaped or (b) they appear as a matched pair of brackets,
- with an open bracket `[`, a sequence of zero or more inlines, and
- a close bracket `]`.
-
-- Backtick [code spans], [autolinks], and raw [HTML tags] bind more tightly
- than the brackets in link text. Thus, for example,
- `` [foo`]` `` could not be a link text, since the second `]`
- is part of a code span.
-
-- The brackets in link text bind more tightly than markers for
- [emphasis and strong emphasis]. Thus, for example, `*[foo*](url)` is a link.
-
-A [link destination](@) consists of either
-
-- a sequence of zero or more characters between an opening `<` and a
- closing `>` that contains no spaces, line breaks, or unescaped
- `<` or `>` characters, or
-
-- a nonempty sequence of characters that does not include
- ASCII space or control characters, and includes parentheses
- only if (a) they are backslash-escaped or (b) they are part of
- a balanced pair of unescaped parentheses that is not itself
- inside a balanced pair of unescaped parentheses.
-
-A [link title](@) consists of either
-
-- a sequence of zero or more characters between straight double-quote
- characters (`"`), including a `"` character only if it is
- backslash-escaped, or
-
-- a sequence of zero or more characters between straight single-quote
- characters (`'`), including a `'` character only if it is
- backslash-escaped, or
-
-- a sequence of zero or more characters between matching parentheses
- (`(...)`), including a `)` character only if it is backslash-escaped.
-
-Although [link titles] may span multiple lines, they may not contain
-a [blank line].
-
-An [inline link](@) consists of a [link text] followed immediately
-by a left parenthesis `(`, optional [whitespace], an optional
-[link destination], an optional [link title] separated from the link
-destination by [whitespace], optional [whitespace], and a right
-parenthesis `)`. The link's text consists of the inlines contained
-in the [link text] (excluding the enclosing square brackets).
-The link's URI consists of the link destination, excluding enclosing
-`<...>` if present, with backslash-escapes in effect as described
-above. The link's title consists of the link title, excluding its
-enclosing delimiters, with backslash-escapes in effect as described
-above.
-
-Here is a simple inline link:
-
-```````````````````````````````` example
-[link](/uri "title")
-.
-<p><a href="/uri" title="title">link</a></p>
-````````````````````````````````
-
-
-The title may be omitted:
-
-```````````````````````````````` example
-[link](/uri)
-.
-<p><a href="/uri">link</a></p>
-````````````````````````````````
-
-
-Both the title and the destination may be omitted:
-
-```````````````````````````````` example
-[link]()
-.
-<p><a href="">link</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link](<>)
-.
-<p><a href="">link</a></p>
-````````````````````````````````
-
-
-The destination cannot contain spaces or line breaks,
-even if enclosed in pointy brackets:
-
-```````````````````````````````` example
-[link](/my uri)
-.
-<p>[link](/my uri)</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link](</my uri>)
-.
-<p>[link](</my uri>)</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link](foo
-bar)
-.
-<p>[link](foo
-bar)</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link](<foo
-bar>)
-.
-<p>[link](<foo
-bar>)</p>
-````````````````````````````````
-
-Parentheses inside the link destination may be escaped:
-
-```````````````````````````````` example
-[link](\(foo\))
-.
-<p><a href="(foo)">link</a></p>
-````````````````````````````````
-
-One level of balanced parentheses is allowed without escaping:
-
-```````````````````````````````` example
-[link]((foo)and(bar))
-.
-<p><a href="(foo)and(bar)">link</a></p>
-````````````````````````````````
-
-However, if you have parentheses within parentheses, you need to escape
-or use the `<...>` form:
-
-```````````````````````````````` example
-[link](foo(and(bar)))
-.
-<p>[link](foo(and(bar)))</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link](foo(and\(bar\)))
-.
-<p><a href="foo(and(bar))">link</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link](<foo(and(bar))>)
-.
-<p><a href="foo(and(bar))">link</a></p>
-````````````````````````````````
-
-
-Parentheses and other symbols can also be escaped, as usual
-in Markdown:
-
-```````````````````````````````` example
-[link](foo\)\:)
-.
-<p><a href="foo):">link</a></p>
-````````````````````````````````
-
-
-A link can contain fragment identifiers and queries:
-
-```````````````````````````````` example
-[link](#fragment)
-
-[link](http://example.com#fragment)
-
-[link](http://example.com?foo=3#frag)
-.
-<p><a href="#fragment">link</a></p>
-<p><a href="http://example.com#fragment">link</a></p>
-<p><a href="http://example.com?foo=3#frag">link</a></p>
-````````````````````````````````
-
-
-Note that a backslash before a non-escapable character is
-just a backslash:
-
-```````````````````````````````` example
-[link](foo\bar)
-.
-<p><a href="foo%5Cbar">link</a></p>
-````````````````````````````````
-
-
-URL-escaping should be left alone inside the destination, as all
-URL-escaped characters are also valid URL characters. Entity and
-numerical character references in the destination will be parsed
-into the corresponding Unicode code points, as usual. These may
-be optionally URL-escaped when written as HTML, but this spec
-does not enforce any particular policy for rendering URLs in
-HTML or other formats. Renderers may make different decisions
-about how to escape or normalize URLs in the output.
-
-```````````````````````````````` example
-[link](foo%20bä)
-.
-<p><a href="foo%20b%C3%A4">link</a></p>
-````````````````````````````````
-
-
-Note that, because titles can often be parsed as destinations,
-if you try to omit the destination and keep the title, you'll
-get unexpected results:
-
-```````````````````````````````` example
-[link]("title")
-.
-<p><a href="%22title%22">link</a></p>
-````````````````````````````````
-
-
-Titles may be in single quotes, double quotes, or parentheses:
-
-```````````````````````````````` example
-[link](/url "title")
-[link](/url 'title')
-[link](/url (title))
-.
-<p><a href="/url" title="title">link</a>
-<a href="/url" title="title">link</a>
-<a href="/url" title="title">link</a></p>
-````````````````````````````````
-
-
-Backslash escapes and entity and numeric character references
-may be used in titles:
-
-```````````````````````````````` example
-[link](/url "title \""")
-.
-<p><a href="/url" title="title """>link</a></p>
-````````````````````````````````
-
-
-Nested balanced quotes are not allowed without escaping:
-
-```````````````````````````````` example
-[link](/url "title "and" title")
-.
-<p>[link](/url "title "and" title")</p>
-````````````````````````````````
-
-
-But it is easy to work around this by using a different quote type:
-
-```````````````````````````````` example
-[link](/url 'title "and" title')
-.
-<p><a href="/url" title="title "and" title">link</a></p>
-````````````````````````````````
-
-
-(Note: `Markdown.pl` did allow double quotes inside a double-quoted
-title, and its test suite included a test demonstrating this.
-But it is hard to see a good rationale for the extra complexity this
-brings, since there are already many ways---backslash escaping,
-entity and numeric character references, or using a different
-quote type for the enclosing title---to write titles containing
-double quotes. `Markdown.pl`'s handling of titles has a number
-of other strange features. For example, it allows single-quoted
-titles in inline links, but not reference links. And, in
-reference links but not inline links, it allows a title to begin
-with `"` and end with `)`. `Markdown.pl` 1.0.1 even allows
-titles with no closing quotation mark, though 1.0.2b8 does not.
-It seems preferable to adopt a simple, rational rule that works
-the same way in inline links and link reference definitions.)
-
-[Whitespace] is allowed around the destination and title:
-
-```````````````````````````````` example
-[link]( /uri
- "title" )
-.
-<p><a href="/uri" title="title">link</a></p>
-````````````````````````````````
-
-
-But it is not allowed between the link text and the
-following parenthesis:
-
-```````````````````````````````` example
-[link] (/uri)
-.
-<p>[link] (/uri)</p>
-````````````````````````````````
-
-
-The link text may contain balanced brackets, but not unbalanced ones,
-unless they are escaped:
-
-```````````````````````````````` example
-[link [foo [bar]]](/uri)
-.
-<p><a href="/uri">link [foo [bar]]</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link] bar](/uri)
-.
-<p>[link] bar](/uri)</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link [bar](/uri)
-.
-<p>[link <a href="/uri">bar</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link \[bar](/uri)
-.
-<p><a href="/uri">link [bar</a></p>
-````````````````````````````````
-
-
-The link text may contain inline content:
-
-```````````````````````````````` example
-[link *foo **bar** `#`*](/uri)
-.
-<p><a href="/uri">link <em>foo <strong>bar</strong> <code>#</code></em></a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[](/uri)
-.
-<p><a href="/uri"><img src="moon.jpg" alt="moon" /></a></p>
-````````````````````````````````
-
-
-However, links may not contain other links, at any level of nesting.
-
-```````````````````````````````` example
-[foo [bar](/uri)](/uri)
-.
-<p>[foo <a href="/uri">bar</a>](/uri)</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo *[bar [baz](/uri)](/uri)*](/uri)
-.
-<p>[foo <em>[bar <a href="/uri">baz</a>](/uri)</em>](/uri)</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-](uri2)](uri3)
-.
-<p><img src="uri3" alt="[foo](uri2)" /></p>
-````````````````````````````````
-
-
-These cases illustrate the precedence of link text grouping over
-emphasis grouping:
-
-```````````````````````````````` example
-*[foo*](/uri)
-.
-<p>*<a href="/uri">foo*</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo *bar](baz*)
-.
-<p><a href="baz*">foo *bar</a></p>
-````````````````````````````````
-
-
-Note that brackets that *aren't* part of links do not take
-precedence:
-
-```````````````````````````````` example
-*foo [bar* baz]
-.
-<p><em>foo [bar</em> baz]</p>
-````````````````````````````````
-
-
-These cases illustrate the precedence of HTML tags, code spans,
-and autolinks over link grouping:
-
-```````````````````````````````` example
-[foo <bar attr="](baz)">
-.
-<p>[foo <bar attr="](baz)"></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo`](/uri)`
-.
-<p>[foo<code>](/uri)</code></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo<http://example.com/?search=](uri)>
-.
-<p>[foo<a href="http://example.com/?search=%5D(uri)">http://example.com/?search=](uri)</a></p>
-````````````````````````````````
-
-
-There are three kinds of [reference link](@)s:
-[full](#full-reference-link), [collapsed](#collapsed-reference-link),
-and [shortcut](#shortcut-reference-link).
-
-A [full reference link](@)
-consists of a [link text] immediately followed by a [link label]
-that [matches] a [link reference definition] elsewhere in the document.
-
-A [link label](@) begins with a left bracket (`[`) and ends
-with the first right bracket (`]`) that is not backslash-escaped.
-Between these brackets there must be at least one [non-whitespace character].
-Unescaped square bracket characters are not allowed in
-[link labels]. A link label can have at most 999
-characters inside the square brackets.
-
-One label [matches](@)
-another just in case their normalized forms are equal. To normalize a
-label, perform the *Unicode case fold* and collapse consecutive internal
-[whitespace] to a single space. If there are multiple
-matching reference link definitions, the one that comes first in the
-document is used. (It is desirable in such cases to emit a warning.)
-
-The contents of the first link label are parsed as inlines, which are
-used as the link's text. The link's URI and title are provided by the
-matching [link reference definition].
-
-Here is a simple example:
-
-```````````````````````````````` example
-[foo][bar]
-
-[bar]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-````````````````````````````````
-
-
-The rules for the [link text] are the same as with
-[inline links]. Thus:
-
-The link text may contain balanced brackets, but not unbalanced ones,
-unless they are escaped:
-
-```````````````````````````````` example
-[link [foo [bar]]][ref]
-
-[ref]: /uri
-.
-<p><a href="/uri">link [foo [bar]]</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[link \[bar][ref]
-
-[ref]: /uri
-.
-<p><a href="/uri">link [bar</a></p>
-````````````````````````````````
-
-
-The link text may contain inline content:
-
-```````````````````````````````` example
-[link *foo **bar** `#`*][ref]
-
-[ref]: /uri
-.
-<p><a href="/uri">link <em>foo <strong>bar</strong> <code>#</code></em></a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[][ref]
-
-[ref]: /uri
-.
-<p><a href="/uri"><img src="moon.jpg" alt="moon" /></a></p>
-````````````````````````````````
-
-
-However, links may not contain other links, at any level of nesting.
-
-```````````````````````````````` example
-[foo [bar](/uri)][ref]
-
-[ref]: /uri
-.
-<p>[foo <a href="/uri">bar</a>]<a href="/uri">ref</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo *bar [baz][ref]*][ref]
-
-[ref]: /uri
-.
-<p>[foo <em>bar <a href="/uri">baz</a></em>]<a href="/uri">ref</a></p>
-````````````````````````````````
-
-
-(In the examples above, we have two [shortcut reference links]
-instead of one [full reference link].)
-
-The following cases illustrate the precedence of link text grouping over
-emphasis grouping:
-
-```````````````````````````````` example
-*[foo*][ref]
-
-[ref]: /uri
-.
-<p>*<a href="/uri">foo*</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo *bar][ref]
-
-[ref]: /uri
-.
-<p><a href="/uri">foo *bar</a></p>
-````````````````````````````````
-
-
-These cases illustrate the precedence of HTML tags, code spans,
-and autolinks over link grouping:
-
-```````````````````````````````` example
-[foo <bar attr="][ref]">
-
-[ref]: /uri
-.
-<p>[foo <bar attr="][ref]"></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo`][ref]`
-
-[ref]: /uri
-.
-<p>[foo<code>][ref]</code></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo<http://example.com/?search=][ref]>
-
-[ref]: /uri
-.
-<p>[foo<a href="http://example.com/?search=%5D%5Bref%5D">http://example.com/?search=][ref]</a></p>
-````````````````````````````````
-
-
-Matching is case-insensitive:
-
-```````````````````````````````` example
-[foo][BaR]
-
-[bar]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-````````````````````````````````
-
-
-Unicode case fold is used:
-
-```````````````````````````````` example
-[Толпой][Толпой] is a Russian word.
-
-[ТОЛПОЙ]: /url
-.
-<p><a href="/url">Толпой</a> is a Russian word.</p>
-````````````````````````````````
-
-
-Consecutive internal [whitespace] is treated as one space for
-purposes of determining matching:
-
-```````````````````````````````` example
-[Foo
- bar]: /url
-
-[Baz][Foo bar]
-.
-<p><a href="/url">Baz</a></p>
-````````````````````````````````
-
-
-No [whitespace] is allowed between the [link text] and the
-[link label]:
-
-```````````````````````````````` example
-[foo] [bar]
-
-[bar]: /url "title"
-.
-<p>[foo] <a href="/url" title="title">bar</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo]
-[bar]
-
-[bar]: /url "title"
-.
-<p>[foo]
-<a href="/url" title="title">bar</a></p>
-````````````````````````````````
-
-
-This is a departure from John Gruber's original Markdown syntax
-description, which explicitly allows whitespace between the link
-text and the link label. It brings reference links in line with
-[inline links], which (according to both original Markdown and
-this spec) cannot have whitespace after the link text. More
-importantly, it prevents inadvertent capture of consecutive
-[shortcut reference links]. If whitespace is allowed between the
-link text and the link label, then in the following we will have
-a single reference link, not two shortcut reference links, as
-intended:
-
-``` markdown
-[foo]
-[bar]
-
-[foo]: /url1
-[bar]: /url2
-```
-
-(Note that [shortcut reference links] were introduced by Gruber
-himself in a beta version of `Markdown.pl`, but never included
-in the official syntax description. Without shortcut reference
-links, it is harmless to allow space between the link text and
-link label; but once shortcut references are introduced, it is
-too dangerous to allow this, as it frequently leads to
-unintended results.)
-
-When there are multiple matching [link reference definitions],
-the first is used:
-
-```````````````````````````````` example
-[foo]: /url1
-
-[foo]: /url2
-
-[bar][foo]
-.
-<p><a href="/url1">bar</a></p>
-````````````````````````````````
-
-
-Note that matching is performed on normalized strings, not parsed
-inline content. So the following does not match, even though the
-labels define equivalent inline content:
-
-```````````````````````````````` example
-[bar][foo\!]
-
-[foo!]: /url
-.
-<p>[bar][foo!]</p>
-````````````````````````````````
-
-
-[Link labels] cannot contain brackets, unless they are
-backslash-escaped:
-
-```````````````````````````````` example
-[foo][ref[]
-
-[ref[]: /uri
-.
-<p>[foo][ref[]</p>
-<p>[ref[]: /uri</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo][ref[bar]]
-
-[ref[bar]]: /uri
-.
-<p>[foo][ref[bar]]</p>
-<p>[ref[bar]]: /uri</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[[[foo]]]
-
-[[[foo]]]: /url
-.
-<p>[[[foo]]]</p>
-<p>[[[foo]]]: /url</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[foo][ref\[]
-
-[ref\[]: /uri
-.
-<p><a href="/uri">foo</a></p>
-````````````````````````````````
-
-
-Note that in this example `]` is not backslash-escaped:
-
-```````````````````````````````` example
-[bar\\]: /uri
-
-[bar\\]
-.
-<p><a href="/uri">bar\</a></p>
-````````````````````````````````
-
-
-A [link label] must contain at least one [non-whitespace character]:
-
-```````````````````````````````` example
-[]
-
-[]: /uri
-.
-<p>[]</p>
-<p>[]: /uri</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[
- ]
-
-[
- ]: /uri
-.
-<p>[
-]</p>
-<p>[
-]: /uri</p>
-````````````````````````````````
-
-
-A [collapsed reference link](@)
-consists of a [link label] that [matches] a
-[link reference definition] elsewhere in the
-document, followed by the string `[]`.
-The contents of the first link label are parsed as inlines,
-which are used as the link's text. The link's URI and title are
-provided by the matching reference link definition. Thus,
-`[foo][]` is equivalent to `[foo][foo]`.
-
-```````````````````````````````` example
-[foo][]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[*foo* bar][]
-
-[*foo* bar]: /url "title"
-.
-<p><a href="/url" title="title"><em>foo</em> bar</a></p>
-````````````````````````````````
-
-
-The link labels are case-insensitive:
-
-```````````````````````````````` example
-[Foo][]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">Foo</a></p>
-````````````````````````````````
-
-
-
-As with full reference links, [whitespace] is not
-allowed between the two sets of brackets:
-
-```````````````````````````````` example
-[foo]
-[]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">foo</a>
-[]</p>
-````````````````````````````````
-
-
-A [shortcut reference link](@)
-consists of a [link label] that [matches] a
-[link reference definition] elsewhere in the
-document and is not followed by `[]` or a link label.
-The contents of the first link label are parsed as inlines,
-which are used as the link's text. the link's URI and title
-are provided by the matching link reference definition.
-Thus, `[foo]` is equivalent to `[foo][]`.
-
-```````````````````````````````` example
-[foo]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[*foo* bar]
-
-[*foo* bar]: /url "title"
-.
-<p><a href="/url" title="title"><em>foo</em> bar</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[[*foo* bar]]
-
-[*foo* bar]: /url "title"
-.
-<p>[<a href="/url" title="title"><em>foo</em> bar</a>]</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-[[bar [foo]
-
-[foo]: /url
-.
-<p>[[bar <a href="/url">foo</a></p>
-````````````````````````````````
-
-
-The link labels are case-insensitive:
-
-```````````````````````````````` example
-[Foo]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">Foo</a></p>
-````````````````````````````````
-
-
-A space after the link text should be preserved:
-
-```````````````````````````````` example
-[foo] bar
-
-[foo]: /url
-.
-<p><a href="/url">foo</a> bar</p>
-````````````````````````````````
-
-
-If you just want bracketed text, you can backslash-escape the
-opening bracket to avoid links:
-
-```````````````````````````````` example
-\[foo]
-
-[foo]: /url "title"
-.
-<p>[foo]</p>
-````````````````````````````````
-
-
-Note that this is a link, because a link label ends with the first
-following closing bracket:
-
-```````````````````````````````` example
-[foo*]: /url
-
-*[foo*]
-.
-<p>*<a href="/url">foo*</a></p>
-````````````````````````````````
-
-
-Full references take precedence over shortcut references:
-
-```````````````````````````````` example
-[foo][bar]
-
-[foo]: /url1
-[bar]: /url2
-.
-<p><a href="/url2">foo</a></p>
-````````````````````````````````
-
-
-In the following case `[bar][baz]` is parsed as a reference,
-`[foo]` as normal text:
-
-```````````````````````````````` example
-[foo][bar][baz]
-
-[baz]: /url
-.
-<p>[foo]<a href="/url">bar</a></p>
-````````````````````````````````
-
-
-Here, though, `[foo][bar]` is parsed as a reference, since
-`[bar]` is defined:
-
-```````````````````````````````` example
-[foo][bar][baz]
-
-[baz]: /url1
-[bar]: /url2
-.
-<p><a href="/url2">foo</a><a href="/url1">baz</a></p>
-````````````````````````````````
-
-
-Here `[foo]` is not parsed as a shortcut reference, because it
-is followed by a link label (even though `[bar]` is not defined):
-
-```````````````````````````````` example
-[foo][bar][baz]
-
-[baz]: /url1
-[foo]: /url2
-.
-<p>[foo]<a href="/url1">bar</a></p>
-````````````````````````````````
-
-
-
-## Images
-
-Syntax for images is like the syntax for links, with one
-difference. Instead of [link text], we have an
-[image description](@). The rules for this are the
-same as for [link text], except that (a) an
-image description starts with `
-.
-<p><img src="/url" alt="foo" title="title" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-![foo *bar*]
-
-[foo *bar*]: train.jpg "train & tracks"
-.
-<p><img src="train.jpg" alt="foo bar" title="train & tracks" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-](/url2)
-.
-<p><img src="/url2" alt="foo bar" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-](/url2)
-.
-<p><img src="/url2" alt="foo bar" /></p>
-````````````````````````````````
-
-
-Though this spec is concerned with parsing, not rendering, it is
-recommended that in rendering to HTML, only the plain string content
-of the [image description] be used. Note that in
-the above example, the alt attribute's value is `foo bar`, not `foo
-[bar](/url)` or `foo <a href="/url">bar</a>`. Only the plain string
-content is rendered, without formatting.
-
-```````````````````````````````` example
-![foo *bar*][]
-
-[foo *bar*]: train.jpg "train & tracks"
-.
-<p><img src="train.jpg" alt="foo bar" title="train & tracks" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-![foo *bar*][foobar]
-
-[FOOBAR]: train.jpg "train & tracks"
-.
-<p><img src="train.jpg" alt="foo bar" title="train & tracks" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-
-.
-<p><img src="train.jpg" alt="foo" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-My 
-.
-<p>My <img src="/path/to/train.jpg" alt="foo bar" title="title" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-
-.
-<p><img src="url" alt="foo" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-
-.
-<p><img src="/url" alt="" /></p>
-````````````````````````````````
-
-
-Reference-style:
-
-```````````````````````````````` example
-![foo][bar]
-
-[bar]: /url
-.
-<p><img src="/url" alt="foo" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-![foo][bar]
-
-[BAR]: /url
-.
-<p><img src="/url" alt="foo" /></p>
-````````````````````````````````
-
-
-Collapsed:
-
-```````````````````````````````` example
-![foo][]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="foo" title="title" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-![*foo* bar][]
-
-[*foo* bar]: /url "title"
-.
-<p><img src="/url" alt="foo bar" title="title" /></p>
-````````````````````````````````
-
-
-The labels are case-insensitive:
-
-```````````````````````````````` example
-![Foo][]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="Foo" title="title" /></p>
-````````````````````````````````
-
-
-As with reference links, [whitespace] is not allowed
-between the two sets of brackets:
-
-```````````````````````````````` example
-![foo]
-[]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="foo" title="title" />
-[]</p>
-````````````````````````````````
-
-
-Shortcut:
-
-```````````````````````````````` example
-![foo]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="foo" title="title" /></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-![*foo* bar]
-
-[*foo* bar]: /url "title"
-.
-<p><img src="/url" alt="foo bar" title="title" /></p>
-````````````````````````````````
-
-
-Note that link labels cannot contain unescaped brackets:
-
-```````````````````````````````` example
-![[foo]]
-
-[[foo]]: /url "title"
-.
-<p>![[foo]]</p>
-<p>[[foo]]: /url "title"</p>
-````````````````````````````````
-
-
-The link labels are case-insensitive:
-
-```````````````````````````````` example
-![Foo]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="Foo" title="title" /></p>
-````````````````````````````````
-
-
-If you just want bracketed text, you can backslash-escape the
-opening `!` and `[`:
-
-```````````````````````````````` example
-\!\[foo]
-
-[foo]: /url "title"
-.
-<p>![foo]</p>
-````````````````````````````````
-
-
-If you want a link after a literal `!`, backslash-escape the
-`!`:
-
-```````````````````````````````` example
-\![foo]
-
-[foo]: /url "title"
-.
-<p>!<a href="/url" title="title">foo</a></p>
-````````````````````````````````
-
-
-## Autolinks
-
-[Autolink](@)s are absolute URIs and email addresses inside
-`<` and `>`. They are parsed as links, with the URL or email address
-as the link label.
-
-A [URI autolink](@) consists of `<`, followed by an
-[absolute URI] not containing `<`, followed by `>`. It is parsed as
-a link to the URI, with the URI as the link's label.
-
-An [absolute URI](@),
-for these purposes, consists of a [scheme] followed by a colon (`:`)
-followed by zero or more characters other than ASCII
-[whitespace] and control characters, `<`, and `>`. If
-the URI includes these characters, they must be percent-encoded
-(e.g. `%20` for a space).
-
-For purposes of this spec, a [scheme](@) is any sequence
-of 2--32 characters beginning with an ASCII letter and followed
-by any combination of ASCII letters, digits, or the symbols plus
-("+"), period ("."), or hyphen ("-").
-
-Here are some valid autolinks:
-
-```````````````````````````````` example
-<http://foo.bar.baz>
-.
-<p><a href="http://foo.bar.baz">http://foo.bar.baz</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<http://foo.bar.baz/test?q=hello&id=22&boolean>
-.
-<p><a href="http://foo.bar.baz/test?q=hello&id=22&boolean">http://foo.bar.baz/test?q=hello&id=22&boolean</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<irc://foo.bar:2233/baz>
-.
-<p><a href="irc://foo.bar:2233/baz">irc://foo.bar:2233/baz</a></p>
-````````````````````````````````
-
-
-Uppercase is also fine:
-
-```````````````````````````````` example
-<MAILTO:FOO@BAR.BAZ>
-.
-<p><a href="MAILTO:FOO@BAR.BAZ">MAILTO:FOO@BAR.BAZ</a></p>
-````````````````````````````````
-
-
-Note that many strings that count as [absolute URIs] for
-purposes of this spec are not valid URIs, because their
-schemes are not registered or because of other problems
-with their syntax:
-
-```````````````````````````````` example
-<a+b+c:d>
-.
-<p><a href="a+b+c:d">a+b+c:d</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<made-up-scheme://foo,bar>
-.
-<p><a href="made-up-scheme://foo,bar">made-up-scheme://foo,bar</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<http://../>
-.
-<p><a href="http://../">http://../</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<localhost:5001/foo>
-.
-<p><a href="localhost:5001/foo">localhost:5001/foo</a></p>
-````````````````````````````````
-
-
-Spaces are not allowed in autolinks:
-
-```````````````````````````````` example
-<http://foo.bar/baz bim>
-.
-<p><http://foo.bar/baz bim></p>
-````````````````````````````````
-
-
-Backslash-escapes do not work inside autolinks:
-
-```````````````````````````````` example
-<http://example.com/\[\>
-.
-<p><a href="http://example.com/%5C%5B%5C">http://example.com/\[\</a></p>
-````````````````````````````````
-
-
-An [email autolink](@)
-consists of `<`, followed by an [email address],
-followed by `>`. The link's label is the email address,
-and the URL is `mailto:` followed by the email address.
-
-An [email address](@),
-for these purposes, is anything that matches
-the [non-normative regex from the HTML5
-spec](https://html.spec.whatwg.org/multipage/forms.html#e-mail-state-(type=email)):
-
- /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?
- (?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/
-
-Examples of email autolinks:
-
-```````````````````````````````` example
-<foo@bar.example.com>
-.
-<p><a href="mailto:foo@bar.example.com">foo@bar.example.com</a></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<foo+special@Bar.baz-bar0.com>
-.
-<p><a href="mailto:foo+special@Bar.baz-bar0.com">foo+special@Bar.baz-bar0.com</a></p>
-````````````````````````````````
-
-
-Backslash-escapes do not work inside email autolinks:
-
-```````````````````````````````` example
-<foo\+@bar.example.com>
-.
-<p><foo+@bar.example.com></p>
-````````````````````````````````
-
-
-These are not autolinks:
-
-```````````````````````````````` example
-<>
-.
-<p><></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-< http://foo.bar >
-.
-<p>< http://foo.bar ></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<m:abc>
-.
-<p><m:abc></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<foo.bar.baz>
-.
-<p><foo.bar.baz></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-http://example.com
-.
-<p>http://example.com</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo@bar.example.com
-.
-<p>foo@bar.example.com</p>
-````````````````````````````````
-
-
-## Raw HTML
-
-Text between `<` and `>` that looks like an HTML tag is parsed as a
-raw HTML tag and will be rendered in HTML without escaping.
-Tag and attribute names are not limited to current HTML tags,
-so custom tags (and even, say, DocBook tags) may be used.
-
-Here is the grammar for tags:
-
-A [tag name](@) consists of an ASCII letter
-followed by zero or more ASCII letters, digits, or
-hyphens (`-`).
-
-An [attribute](@) consists of [whitespace],
-an [attribute name], and an optional
-[attribute value specification].
-
-An [attribute name](@)
-consists of an ASCII letter, `_`, or `:`, followed by zero or more ASCII
-letters, digits, `_`, `.`, `:`, or `-`. (Note: This is the XML
-specification restricted to ASCII. HTML5 is laxer.)
-
-An [attribute value specification](@)
-consists of optional [whitespace],
-a `=` character, optional [whitespace], and an [attribute
-value].
-
-An [attribute value](@)
-consists of an [unquoted attribute value],
-a [single-quoted attribute value], or a [double-quoted attribute value].
-
-An [unquoted attribute value](@)
-is a nonempty string of characters not
-including spaces, `"`, `'`, `=`, `<`, `>`, or `` ` ``.
-
-A [single-quoted attribute value](@)
-consists of `'`, zero or more
-characters not including `'`, and a final `'`.
-
-A [double-quoted attribute value](@)
-consists of `"`, zero or more
-characters not including `"`, and a final `"`.
-
-An [open tag](@) consists of a `<` character, a [tag name],
-zero or more [attributes], optional [whitespace], an optional `/`
-character, and a `>` character.
-
-A [closing tag](@) consists of the string `</`, a
-[tag name], optional [whitespace], and the character `>`.
-
-An [HTML comment](@) consists of `<!--` + *text* + `-->`,
-where *text* does not start with `>` or `->`, does not end with `-`,
-and does not contain `--`. (See the
-[HTML5 spec](http://www.w3.org/TR/html5/syntax.html#comments).)
-
-A [processing instruction](@)
-consists of the string `<?`, a string
-of characters not including the string `?>`, and the string
-`?>`.
-
-A [declaration](@) consists of the
-string `<!`, a name consisting of one or more uppercase ASCII letters,
-[whitespace], a string of characters not including the
-character `>`, and the character `>`.
-
-A [CDATA section](@) consists of
-the string `<![CDATA[`, a string of characters not including the string
-`]]>`, and the string `]]>`.
-
-An [HTML tag](@) consists of an [open tag], a [closing tag],
-an [HTML comment], a [processing instruction], a [declaration],
-or a [CDATA section].
-
-Here are some simple open tags:
-
-```````````````````````````````` example
-<a><bab><c2c>
-.
-<p><a><bab><c2c></p>
-````````````````````````````````
-
-
-Empty elements:
-
-```````````````````````````````` example
-<a/><b2/>
-.
-<p><a/><b2/></p>
-````````````````````````````````
-
-
-[Whitespace] is allowed:
-
-```````````````````````````````` example
-<a /><b2
-data="foo" >
-.
-<p><a /><b2
-data="foo" ></p>
-````````````````````````````````
-
-
-With attributes:
-
-```````````````````````````````` example
-<a foo="bar" bam = 'baz <em>"</em>'
-_boolean zoop:33=zoop:33 />
-.
-<p><a foo="bar" bam = 'baz <em>"</em>'
-_boolean zoop:33=zoop:33 /></p>
-````````````````````````````````
-
-
-Custom tag names can be used:
-
-```````````````````````````````` example
-Foo <responsive-image src="foo.jpg" />
-.
-<p>Foo <responsive-image src="foo.jpg" /></p>
-````````````````````````````````
-
-
-Illegal tag names, not parsed as HTML:
-
-```````````````````````````````` example
-<33> <__>
-.
-<p><33> <__></p>
-````````````````````````````````
-
-
-Illegal attribute names:
-
-```````````````````````````````` example
-<a h*#ref="hi">
-.
-<p><a h*#ref="hi"></p>
-````````````````````````````````
-
-
-Illegal attribute values:
-
-```````````````````````````````` example
-<a href="hi'> <a href=hi'>
-.
-<p><a href="hi'> <a href=hi'></p>
-````````````````````````````````
-
-
-Illegal [whitespace]:
-
-```````````````````````````````` example
-< a><
-foo><bar/ >
-.
-<p>< a><
-foo><bar/ ></p>
-````````````````````````````````
-
-
-Missing [whitespace]:
-
-```````````````````````````````` example
-<a href='bar'title=title>
-.
-<p><a href='bar'title=title></p>
-````````````````````````````````
-
-
-Closing tags:
-
-```````````````````````````````` example
-</a></foo >
-.
-<p></a></foo ></p>
-````````````````````````````````
-
-
-Illegal attributes in closing tag:
-
-```````````````````````````````` example
-</a href="foo">
-.
-<p></a href="foo"></p>
-````````````````````````````````
-
-
-Comments:
-
-```````````````````````````````` example
-foo <!-- this is a
-comment - with hyphen -->
-.
-<p>foo <!-- this is a
-comment - with hyphen --></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo <!-- not a comment -- two hyphens -->
-.
-<p>foo <!-- not a comment -- two hyphens --></p>
-````````````````````````````````
-
-
-Not comments:
-
-```````````````````````````````` example
-foo <!--> foo -->
-
-foo <!-- foo--->
-.
-<p>foo <!--> foo --></p>
-<p>foo <!-- foo---></p>
-````````````````````````````````
-
-
-Processing instructions:
-
-```````````````````````````````` example
-foo <?php echo $a; ?>
-.
-<p>foo <?php echo $a; ?></p>
-````````````````````````````````
-
-
-Declarations:
-
-```````````````````````````````` example
-foo <!ELEMENT br EMPTY>
-.
-<p>foo <!ELEMENT br EMPTY></p>
-````````````````````````````````
-
-
-CDATA sections:
-
-```````````````````````````````` example
-foo <![CDATA[>&<]]>
-.
-<p>foo <![CDATA[>&<]]></p>
-````````````````````````````````
-
-
-Entity and numeric character references are preserved in HTML
-attributes:
-
-```````````````````````````````` example
-foo <a href="ö">
-.
-<p>foo <a href="ö"></p>
-````````````````````````````````
-
-
-Backslash escapes do not work in HTML attributes:
-
-```````````````````````````````` example
-foo <a href="\*">
-.
-<p>foo <a href="\*"></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<a href="\"">
-.
-<p><a href="""></p>
-````````````````````````````````
-
-
-## Hard line breaks
-
-A line break (not in a code span or HTML tag) that is preceded
-by two or more spaces and does not occur at the end of a block
-is parsed as a [hard line break](@) (rendered
-in HTML as a `<br />` tag):
-
-```````````````````````````````` example
-foo
-baz
-.
-<p>foo<br />
-baz</p>
-````````````````````````````````
-
-
-For a more visible alternative, a backslash before the
-[line ending] may be used instead of two spaces:
-
-```````````````````````````````` example
-foo\
-baz
-.
-<p>foo<br />
-baz</p>
-````````````````````````````````
-
-
-More than two spaces can be used:
-
-```````````````````````````````` example
-foo
-baz
-.
-<p>foo<br />
-baz</p>
-````````````````````````````````
-
-
-Leading spaces at the beginning of the next line are ignored:
-
-```````````````````````````````` example
-foo
- bar
-.
-<p>foo<br />
-bar</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo\
- bar
-.
-<p>foo<br />
-bar</p>
-````````````````````````````````
-
-
-Line breaks can occur inside emphasis, links, and other constructs
-that allow inline content:
-
-```````````````````````````````` example
-*foo
-bar*
-.
-<p><em>foo<br />
-bar</em></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-*foo\
-bar*
-.
-<p><em>foo<br />
-bar</em></p>
-````````````````````````````````
-
-
-Line breaks do not occur inside code spans
-
-```````````````````````````````` example
-`code
-span`
-.
-<p><code>code span</code></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-`code\
-span`
-.
-<p><code>code\ span</code></p>
-````````````````````````````````
-
-
-or HTML tags:
-
-```````````````````````````````` example
-<a href="foo
-bar">
-.
-<p><a href="foo
-bar"></p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-<a href="foo\
-bar">
-.
-<p><a href="foo\
-bar"></p>
-````````````````````````````````
-
-
-Hard line breaks are for separating inline content within a block.
-Neither syntax for hard line breaks works at the end of a paragraph or
-other block element:
-
-```````````````````````````````` example
-foo\
-.
-<p>foo\</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-foo
-.
-<p>foo</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-### foo\
-.
-<h3>foo\</h3>
-````````````````````````````````
-
-
-```````````````````````````````` example
-### foo
-.
-<h3>foo</h3>
-````````````````````````````````
-
-
-## Soft line breaks
-
-A regular line break (not in a code span or HTML tag) that is not
-preceded by two or more spaces or a backslash is parsed as a
-softbreak. (A softbreak may be rendered in HTML either as a
-[line ending] or as a space. The result will be the same in
-browsers. In the examples here, a [line ending] will be used.)
-
-```````````````````````````````` example
-foo
-baz
-.
-<p>foo
-baz</p>
-````````````````````````````````
-
-
-Spaces at the end of the line and beginning of the next line are
-removed:
-
-```````````````````````````````` example
-foo
- baz
-.
-<p>foo
-baz</p>
-````````````````````````````````
-
-
-A conforming parser may render a soft line break in HTML either as a
-line break or as a space.
-
-A renderer may also provide an option to render soft line breaks
-as hard line breaks.
-
-## Textual content
-
-Any characters not given an interpretation by the above rules will
-be parsed as plain textual content.
-
-```````````````````````````````` example
-hello $.;'there
-.
-<p>hello $.;'there</p>
-````````````````````````````````
-
-
-```````````````````````````````` example
-Foo χρῆν
-.
-<p>Foo χρῆν</p>
-````````````````````````````````
-
-
-Internal spaces are preserved verbatim:
-
-```````````````````````````````` example
-Multiple spaces
-.
-<p>Multiple spaces</p>
-````````````````````````````````
-
-
-<!-- END TESTS -->
-
-# Appendix: A parsing strategy
-
-In this appendix we describe some features of the parsing strategy
-used in the CommonMark reference implementations.
-
-## Overview
-
-Parsing has two phases:
-
-1. In the first phase, lines of input are consumed and the block
-structure of the document---its division into paragraphs, block quotes,
-list items, and so on---is constructed. Text is assigned to these
-blocks but not parsed. Link reference definitions are parsed and a
-map of links is constructed.
-
-2. In the second phase, the raw text contents of paragraphs and headings
-are parsed into sequences of Markdown inline elements (strings,
-code spans, links, emphasis, and so on), using the map of link
-references constructed in phase 1.
-
-At each point in processing, the document is represented as a tree of
-**blocks**. The root of the tree is a `document` block. The `document`
-may have any number of other blocks as **children**. These children
-may, in turn, have other blocks as children. The last child of a block
-is normally considered **open**, meaning that subsequent lines of input
-can alter its contents. (Blocks that are not open are **closed**.)
-Here, for example, is a possible document tree, with the open blocks
-marked by arrows:
-
-``` tree
--> document
- -> block_quote
- paragraph
- "Lorem ipsum dolor\nsit amet."
- -> list (type=bullet tight=true bullet_char=-)
- list_item
- paragraph
- "Qui *quodsi iracundia*"
- -> list_item
- -> paragraph
- "aliquando id"
-```
-
-## Phase 1: block structure
-
-Each line that is processed has an effect on this tree. The line is
-analyzed and, depending on its contents, the document may be altered
-in one or more of the following ways:
-
-1. One or more open blocks may be closed.
-2. One or more new blocks may be created as children of the
- last open block.
-3. Text may be added to the last (deepest) open block remaining
- on the tree.
-
-Once a line has been incorporated into the tree in this way,
-it can be discarded, so input can be read in a stream.
-
-For each line, we follow this procedure:
-
-1. First we iterate through the open blocks, starting with the
-root document, and descending through last children down to the last
-open block. Each block imposes a condition that the line must satisfy
-if the block is to remain open. For example, a block quote requires a
-`>` character. A paragraph requires a non-blank line.
-In this phase we may match all or just some of the open
-blocks. But we cannot close unmatched blocks yet, because we may have a
-[lazy continuation line].
-
-2. Next, after consuming the continuation markers for existing
-blocks, we look for new block starts (e.g. `>` for a block quote.
-If we encounter a new block start, we close any blocks unmatched
-in step 1 before creating the new block as a child of the last
-matched block.
-
-3. Finally, we look at the remainder of the line (after block
-markers like `>`, list markers, and indentation have been consumed).
-This is text that can be incorporated into the last open
-block (a paragraph, code block, heading, or raw HTML).
-
-Setext headings are formed when we see a line of a paragraph
-that is a [setext heading underline].
-
-Reference link definitions are detected when a paragraph is closed;
-the accumulated text lines are parsed to see if they begin with
-one or more reference link definitions. Any remainder becomes a
-normal paragraph.
-
-We can see how this works by considering how the tree above is
-generated by four lines of Markdown:
-
-``` markdown
-> Lorem ipsum dolor
-sit amet.
-> - Qui *quodsi iracundia*
-> - aliquando id
-```
-
-At the outset, our document model is just
-
-``` tree
--> document
-```
-
-The first line of our text,
-
-``` markdown
-> Lorem ipsum dolor
-```
-
-causes a `block_quote` block to be created as a child of our
-open `document` block, and a `paragraph` block as a child of
-the `block_quote`. Then the text is added to the last open
-block, the `paragraph`:
-
-``` tree
--> document
- -> block_quote
- -> paragraph
- "Lorem ipsum dolor"
-```
-
-The next line,
-
-``` markdown
-sit amet.
-```
-
-is a "lazy continuation" of the open `paragraph`, so it gets added
-to the paragraph's text:
-
-``` tree
--> document
- -> block_quote
- -> paragraph
- "Lorem ipsum dolor\nsit amet."
-```
-
-The third line,
-
-``` markdown
-> - Qui *quodsi iracundia*
-```
-
-causes the `paragraph` block to be closed, and a new `list` block
-opened as a child of the `block_quote`. A `list_item` is also
-added as a child of the `list`, and a `paragraph` as a child of
-the `list_item`. The text is then added to the new `paragraph`:
-
-``` tree
--> document
- -> block_quote
- paragraph
- "Lorem ipsum dolor\nsit amet."
- -> list (type=bullet tight=true bullet_char=-)
- -> list_item
- -> paragraph
- "Qui *quodsi iracundia*"
-```
-
-The fourth line,
-
-``` markdown
-> - aliquando id
-```
-
-causes the `list_item` (and its child the `paragraph`) to be closed,
-and a new `list_item` opened up as child of the `list`. A `paragraph`
-is added as a child of the new `list_item`, to contain the text.
-We thus obtain the final tree:
-
-``` tree
--> document
- -> block_quote
- paragraph
- "Lorem ipsum dolor\nsit amet."
- -> list (type=bullet tight=true bullet_char=-)
- list_item
- paragraph
- "Qui *quodsi iracundia*"
- -> list_item
- -> paragraph
- "aliquando id"
-```
-
-## Phase 2: inline structure
-
-Once all of the input has been parsed, all open blocks are closed.
-
-We then "walk the tree," visiting every node, and parse raw
-string contents of paragraphs and headings as inlines. At this
-point we have seen all the link reference definitions, so we can
-resolve reference links as we go.
-
-``` tree
-document
- block_quote
- paragraph
- str "Lorem ipsum dolor"
- softbreak
- str "sit amet."
- list (type=bullet tight=true bullet_char=-)
- list_item
- paragraph
- str "Qui "
- emph
- str "quodsi iracundia"
- list_item
- paragraph
- str "aliquando id"
-```
-
-Notice how the [line ending] in the first paragraph has
-been parsed as a `softbreak`, and the asterisks in the first list item
-have become an `emph`.
-
-### An algorithm for parsing nested emphasis and links
-
-By far the trickiest part of inline parsing is handling emphasis,
-strong emphasis, links, and images. This is done using the following
-algorithm.
-
-When we're parsing inlines and we hit either
-
-- a run of `*` or `_` characters, or
-- a `[` or `.
-
-The [delimiter stack] is a doubly linked list. Each
-element contains a pointer to a text node, plus information about
-
-- the type of delimiter (`[`, `![`, `*`, `_`)
-- the number of delimiters,
-- whether the delimiter is "active" (all are active to start), and
-- whether the delimiter is a potential opener, a potential closer,
- or both (which depends on what sort of characters precede
- and follow the delimiters).
-
-When we hit a `]` character, we call the *look for link or image*
-procedure (see below).
-
-When we hit the end of the input, we call the *process emphasis*
-procedure (see below), with `stack_bottom` = NULL.
-
-#### *look for link or image*
-
-Starting at the top of the delimiter stack, we look backwards
-through the stack for an opening `[` or `![` delimiter.
-
-- If we don't find one, we return a literal text node `]`.
-
-- If we do find one, but it's not *active*, we remove the inactive
- delimiter from the stack, and return a literal text node `]`.
-
-- If we find one and it's active, then we parse ahead to see if
- we have an inline link/image, reference link/image, compact reference
- link/image, or shortcut reference link/image.
-
- + If we don't, then we remove the opening delimiter from the
- delimiter stack and return a literal text node `]`.
-
- + If we do, then
-
- * We return a link or image node whose children are the inlines
- after the text node pointed to by the opening delimiter.
-
- * We run *process emphasis* on these inlines, with the `[` opener
- as `stack_bottom`.
-
- * We remove the opening delimiter.
-
- * If we have a link (and not an image), we also set all
- `[` delimiters before the opening delimiter to *inactive*. (This
- will prevent us from getting links within links.)
-
-#### *process emphasis*
-
-Parameter `stack_bottom` sets a lower bound to how far we
-descend in the [delimiter stack]. If it is NULL, we can
-go all the way to the bottom. Otherwise, we stop before
-visiting `stack_bottom`.
-
-Let `current_position` point to the element on the [delimiter stack]
-just above `stack_bottom` (or the first element if `stack_bottom`
-is NULL).
-
-We keep track of the `openers_bottom` for each delimiter
-type (`*`, `_`). Initialize this to `stack_bottom`.
-
-Then we repeat the following until we run out of potential
-closers:
-
-- Move `current_position` forward in the delimiter stack (if needed)
- until we find the first potential closer with delimiter `*` or `_`.
- (This will be the potential closer closest
- to the beginning of the input -- the first one in parse order.)
-
-- Now, look back in the stack (staying above `stack_bottom` and
- the `openers_bottom` for this delimiter type) for the
- first matching potential opener ("matching" means same delimiter).
-
-- If one is found:
-
- + Figure out whether we have emphasis or strong emphasis:
- if both closer and opener spans have length >= 2, we have
- strong, otherwise regular.
-
- + Insert an emph or strong emph node accordingly, after
- the text node corresponding to the opener.
-
- + Remove any delimiters between the opener and closer from
- the delimiter stack.
-
- + Remove 1 (for regular emph) or 2 (for strong emph) delimiters
- from the opening and closing text nodes. If they become empty
- as a result, remove them and remove the corresponding element
- of the delimiter stack. If the closing node is removed, reset
- `current_position` to the next element in the stack.
-
-- If none in found:
-
- + Set `openers_bottom` to the element before `current_position`.
- (We know that there are no openers for this kind of closer up to and
- including this point, so this puts a lower bound on future searches.)
-
- + If the closer at `current_position` is not a potential opener,
- remove it from the delimiter stack (since we know it can't
- be a closer either).
-
- + Advance `current_position` to the next element in the stack.
-
-After we're done, we remove all delimiters above `stack_bottom` from the
-delimiter stack.
-
Code Review / simantics / platform.git / blobdiff