0.5 + x * (2e-3 + x * 2) |
0.5 + x * (2e-3 + x * 2) |
x >= 0 && x <= 1 |
x >= 0 && x <= 1 |
Math.sin(a1) - Math.cos(a2) |
sin a1 - cos a2 |
cond ? value : alternative |
if cond then value else alternative |
"I am " + age + " years old." |
"I am " + show age + " years old."
In future:
"I am ${age} years old."
|
final int sum = a + b;
|
sum = a + b
|
public static String decorate(String x) {
return "(" + x + ")";
}
|
decorate :: String -> String
decorate x = "(" + x + ")"
(the first line is optional)
|
{
statement1;
statement2;
statement3;
}
|
do
statement1
statement2
statement3
|
if(cond1)
statement1;
else if(cond2)
statement2;
else
statement3;
|
if cond1
then statement1
else if cond2
then statement2
else statement3
|
for(T x : l)
statement;
|
for l (\x ->
statement
)
|
while(cond) statement;
|
while (\() -> cond) (\() -> statement)
In future with improvements to macros:
while cond statement
|
int var;
switch(value) {
case Label1:
var = case1;
break;
case Label2:
var = case2;
break;
default:
var = case3;
}
|
var = match value with
Label1 -> case1
Label2 -> case2
_ -> case3
|
break;
continue;
return x; // In the middle of the code
| No exact correspondence. However, every control sequence can be written in the following form:
label1 initialState
where
label1 state =
...
then label2 modifiedState1
else label3 modifiedState2
label2 state =
...
label3 state =
...
label1 modifiedState
|
int a, b;
if(cond) {
a = aExp1;
b = bExp1;
}
else {
a = aExp2;
b = bExp2;
}
|
(a, b) = if cond
then (aExp1, bExp1)
else (aExp2, bExp2)
|
int a = 1;
a = 2;
a = 3;
return a;
|
a = ref 1
a := 2
a := 3
getRef a
The name of the function getRef will change in the future and is
probably replaced by some special syntax. For example in ML getRef a
would be written as !a.
|
public static String f(int x) {
if(x >= 0)
return Integer.toString(x);
else
return null;
}
|
f :: Integer -> Maybe String
f x | x >= 0 = Just (show x)
| otherwise = Nothing
|
public static int invF(String s) {
if(s == null)
return -1;
else
return Integer.parseInt(s);
}
|
invF :: Maybe String -> Integer
invF Nothing = -1
invF (Just s) = read s
|
Arrays.asList(new String[] {"x", "y", "z"})
|
[ "x", "y", "z" ]
|
l.get(3)
|
l!3
|
List decorated = new ArrayList();
for(String s : undecorated)
decorated.add("(" + s + ")");
|
decorated = [ "(" + s + ")" | s <- undecorated ]
or
decorated = map (\s -> "(" + s + ")") undecorated
|
List nonempty = new ArrayList();
for(String s : l)
if(!s.isEmpty())
nonempty.add(l);
|
decorated = [ s | s <- l, s != "" ]
or
decorated = filter (\s -> s != "") l
|
List> listOfLists;
List flattened
= new ArrayList();
for(List l : listOfLists)
for(String s : l)
flattened.add(s);
|
flattened = [ s | l <- listOfLists, s <- l ]
or
flattened = sum listOfLists
or
flattened = join listOfLists
|
throw new RuntimeException("Unhandled case.");
|
fail "Unhandled case."
|
try {
...
throw new ExceptionX(...);
...
} catch(ExceptionX e) {
...
} finally {
...
}
|
Currently no correspondence. Exceptions need to be thrown and catched in Java code.
|
synchronized(obj) {
...
}
|
Currently no correspondence. Synchronization must be done in Java code.
|
final static class Vec3 {
public final double x;
public final double y;
public final double z;
public Vec3(double x,
double y,
double x) {
this.x = x;
this.y = y;
this.z = z;
}
}
|
data Vec3 = Vec3 Double Double Double
In future also:
data Vec3 = Vec3 {
x :: Double,
y :: Double,
z :: Double
}
|
public static interface Num {}
public static class Int implements Num {
public static final int value;
public Int(int value) {
this.value = value;
}
}
public static class Real implements Num {
public static final double value;
public Real(double value) {
this.value = value;
}
}
|
data Num = Int Integer
| Real Double
|
public static Num add(Num a_, Num b_) {
if(a_ instanceof Int) {
Int a = (Int)a_;
if(b_ instanceof Int) {
Int b = (Int)b_;
return new Int(a.value + b.value);
}
else if(b_ instanceof Real) {
Real b = (Real)b_;
return new Real(a.value + b.value);
}
}
else if(a_ instanceof Real) {
Real a = (Real)a_;
if(b_ instanceof Int) {
Int b = (Int)b_;
return new Real(a.value + b.value);
}
else if(b_ instanceof Real) {
Real b = (Real)b_;
return new Real(a.value + b.value);
}
}
throw new IllegalArgumentException();
}
|
add :: Num -> Num -> Num
add (Int a) (Int b) = Int (a + b)
add (Int a) (Real b) = Real (fromInteger a + b)
add (Real a) (Int b) = Real (a + fromInteger b)
add (Real a) (Real b) = Real (a + b)
|
public static interface Bijection {
B forward(A v);
A backward(B v);
}
Bijection inc =
new Bijection {
public Integer forward(Integer v) {
return v + 1;
}
public Integer backward(Integer v) {
return v - 1;
}
}
|
data Bijection a b =
Bijection (a -> b) (b -> a)
forward (Bijection f _) v = f v
backward (Bijection _ f) v = f v
inc = Bijection (\v -> v + 1) (\v -> v - 1)
In future:
data Bijection a b = Bijection {
forward :: a -> b,
backward :: b -> a
}
inc = Bijection {
forward v = v + 1,
backward v = v - 1
}
|
=== Longer examples ===