1 import "JavaBuiltin" as Java
2 import "StringBuilder" as StringBuilder
4 /** The following types and names are builtin *************
5 data Boolean = True | False
24 data [a] = [] | [a] | [a,a] | [a,a,a] | ...
27 data (a,b,c) = (a,b,c)
28 data Maybe a = Nothing | Just a
32 data TypeRep = TCon String | TApply TypeRep TypeRep
34 typeOf :: Typeable a => a -> Type
38 binding :: Serializable a => Binding a
39 ***********************************************************/
41 importJava "java.util.Arrays" where
44 showDoubleArray :: DoubleArray -> String
46 "Converts an array to a list."
48 arrayToList :: Array a -> [a]
50 importJava "java.util.List" where
51 "Converts a list to an array."
53 listToArray :: [a] -> Array a
55 instance Show DoubleArray where
56 show = showDoubleArray
58 importJava "org.simantics.scl.runtime.Coercion" where
59 "Converts a list of doubles to a double array."
60 toDoubleArray :: [Double] -> DoubleArray
61 "Converts a double array to a list of doubles."
62 fromDoubleArray :: DoubleArray -> [Double]
65 * Precedences and associativity of all operators defined in Prelude
71 infixl 7 (*), (/), div, mod
73 infixl 5 (\\), (<<), (<+)
74 infix 4 (!=), (<), (<=), (>=), (>)
76 infixr 2 (||), orElse, morelse
77 infixr 1 (>>=), (>>), (:=), (>=>)
81 "Creates a constant function. `const x` defines a function that always returns `x`."
87 Function application. `f $ x` is equivalent with `f x`. The function has two uses.
88 First is to remove parentheses from deeply nested expressions:
90 f (g (h x)) == f $ g $ h x
92 The second use is with higher order functions:
94 map ($ parameter) functions
98 ($) :: (a -> <e> b) -> a -> <e> b
101 "Transforms a function taking a pair as a parameter to a function taking two values as a parameter."
103 curry :: ((a, b) -> <e> c) -> a -> b -> <e> c
104 curry f x y = f (x, y)
106 "Transforms a function two values as a parameter to a function taking a pair as a parameter."
108 uncurry :: (a -> b -> <e> c) -> ((a, b) -> <e> c)
109 uncurry f (x, y) = f x y
111 "Transforms a function taking a triple as a parameter to a function taking three values as a parameter."
113 curry3 :: ((a, b, c) -> <e> d) -> a -> b -> c -> <e> d
114 curry3 f x y z = f (x, y, z)
116 "Transforms a function three values as a parameter to a function taking a priple as a parameter."
118 uncurry3 :: (a -> b -> c -> <e> d) -> ((a, b, c) -> <e> d)
119 uncurry3 f (x, y, z) = f x y z
121 "Flips the parameters of a binary function."
123 flip :: (a -> b -> <e> c) -> b -> a -> <e> c
126 "Swaps the order of elements of a pair (2-tuple)."
127 swap :: (a,b) -> (b,a)
133 (!=) :: a -> a -> Boolean
134 a != b = not (a == b)
137 The class of linearly ordered types.
138 Method `compare` must be implemented in instances.
142 `compare x y` returns a negative number, if `x` is smaller than `y`,
143 a positive number, if `x` is bigger than `y` and zero if they are equal.
145 compare :: a -> a -> Integer
146 compare a b = if a < b then -1 else if a > b then 1 else 0
149 (<) :: a -> a -> Boolean
150 a < b = compare a b < 0
152 (<=) :: a -> a -> Boolean
153 a <= b = compare a b <= 0
155 (>) :: a -> a -> Boolean
156 a > b = compare a b > 0
158 (>=) :: a -> a -> Boolean
159 a >= b = compare a b >= 0
161 "Minimum of the parameters"
163 min a b = if a < b then a else b
164 "Maximum of the parameters"
166 max a b = if a > b then a else b
169 Combines two integers such that if the first one is non-zero, it is returned, otherwise
170 the second-one. The second parameter is not implemented, if it is not needed.
172 The function is useful for implementing efficient recursive comparison of structures,
175 compare (x1,y1,z1) (x2,y2,z2) = compare x1 x2 &<& compare y1 y2 &<& compare z1 z2
178 (&<&) :: Integer -> (<e> Integer) -> <e> Integer
179 a &<& b = if a == 0 then b else a
181 "Maximum over a list"
183 maximum :: Ord a => [a] -> a
186 "Minimum over a list"
188 minimum :: Ord a => [a] -> a
191 "As `maximum` but compares the elements by the given projection."
192 maximumBy :: Ord b => (a -> <e> b) -> [a] -> <e> a
193 maximumBy f l = snd $ foldl1 maxF $ map (\x -> (f x, x)) l
195 maxF a b = if fst a >= fst b then a else b
198 As `minimum` but compares the elements by the given projection.
203 returns a pair with the smallest second component.
205 minimumBy :: Ord b => (a -> <e> b) -> [a] -> <e> a
206 minimumBy f l = snd $ foldl1 minF $ map (\x -> (f x, x)) l
208 minF a b = if fst a <= fst b then a else b
212 instance Functor ((->) a) where
215 instance Monad ((->) a) where
217 (m >>= f) x = f (m x) x
220 instance Category (->) where
225 instance (Additive b) => Additive (a -> <e> b) where
227 (f + g) x = f x + g x
229 instance (Ring b) => Ring (a -> <e> b) where
231 (neg f) x = neg (f x)
232 (f - g) x = f x - g x
233 (f * g) x = f x * g x
234 (fromInteger c) x = fromInteger c
236 //instance Show (a -> <e> b) where
237 // show f = "<function>"
239 "Appends a string to the string builder."
240 (<<) :: StringBuilder.T -> String -> <Proc> StringBuilder.T
241 (<<) = StringBuilder.appendString
244 The class of types whose elements can be converted to a string representation.
245 Method `show` or `(<+)` must be implemented.
248 "Converts a value to string."
250 "Appends the string representation of the value to the string builder."
251 (<+) :: StringBuilder.T -> a -> <Proc> StringBuilder.T
253 Returns the precedence of the value. It is used to determine if parenteheses
254 are needed around the string representation of the value. The default value is 0
255 and means that parentheses are never added.
257 precedence :: a -> Integer
259 "Converts a value to a string like `show` but does not put string literals in double quotes."
260 showForPrinting :: a -> String
262 show v = runProc (StringBuilder.toString (StringBuilder.new <+ v))
263 showForPrinting v = show v
264 sb <+ v = StringBuilder.appendString sb (show v)
268 `Par` data type is used to control the placement of parentheses when converting values to string.
269 Value `Par prec val` is converted to string like `val` but parentheses are put around, if the
270 precedence of the value is greater than `prec`.
272 data Par a = Par Integer a
274 instance (Show a) => Show (Par a) where
275 sb <+ (Par outerPrec v) = if prec > outerPrec
276 then sb << "(" <+ v << ")"
278 where prec = precedence v
280 "Type class for parsing strings to values."
282 "Converts a string to a required type of value."
285 The `Additive` class is used for types that are additive monoids. The operations
286 must satisfy the following laws (at least approximately, when implemented for
287 floating point numbers):
288 (a + b) + c = a + (b + c)
291 class Additive a where
293 Neutral element of (+), i.e,
299 "Adds two objects (numbers, vectors, strings, etc.) together."
304 sum [e1,e2,...,eN] = e1 + e2 + ... + eN
306 Implemented usually more efficiently than with repetitive
307 application of `(+)`.
312 class (Additive a) => AdditiveGroup a where
318 The `Ring` class is used for types that are algebraic rings. The operations
319 must satisfy the following laws (at least approximately)
320 in addition to the laws of Additive:
325 (a * b) * c = a * (b * c)
327 a * (b + c) = a * b + a * c
328 (a + b) * c = a * c + b * c
330 class (Additive a) => Ring a where
332 Negation. Synonym for unary `-`.
337 "Neutral element of multiplication"
341 "Converts an integer to a desired numeric type."
342 fromInteger :: Integer -> a
347 The `OrderedRing` class combines the Ring and Ord classes. It additionally
348 supports absolute value function.
350 class (Ring a, Ord a) => OrderedRing a where
353 abs x = if x < zero then neg x else x
354 "Converts the given number to `Integer`"
355 toInteger :: a -> Integer
358 The `Integer` class is used for types that represent either all integers or some
361 class (OrderedRing a) => Integral a where
362 "Integer division truncated toward zero."
364 "Integer remainder, satisfying ``(x `div` y)*y + (x `mod` y) = x``"
368 The `Real` class is used for types that represent some approximation of real numbers.
370 class (OrderedRing a) => Real a where
375 "Pi (3.141592654...)"
401 "Inverse hyberbolic sine"
403 "Inverse hyberbolic cosine"
405 "Inverse hyberbolic tangent"
407 "The largest integer not greater than the given number"
409 "The smallest integer not smaller than the given number"
413 Two parameter version of `atan`. Its value is determined by the following
414 equations when (x,y) is a unit vector:
421 atan2 y x = atan (y/x)
424 "Converts a `Double` value to a desired numeric type."
425 fromDouble :: Double -> a
426 "Converts the given number to `Double`"
427 toDouble :: a -> Double
429 a ^ b = exp (b * log a)
431 sinh x = 0.5 * (exp x - exp (neg x))
432 cosh x = 0.5 * (exp x + exp (neg x))
433 tanh x = (e2x - 1) / (e2x + 1)
437 asinh x = log (x + sqrt (x*x + one))
438 acosh x = log (x + sqrt (x*x - one))
439 atanh x = 0.5 * log ((one+x)/(one-x))
441 /// Import mathematical functions ///
444 importJava "java.lang.Math" where
449 sinDouble :: Double -> Double
452 cosDouble :: Double -> Double
455 tanDouble :: Double -> Double
458 asinDouble :: Double -> Double
461 acosDouble :: Double -> Double
464 atanDouble :: Double -> Double
467 atan2Double :: Double -> Double -> Double
470 sinhDouble :: Double -> Double
473 coshDouble :: Double -> Double
476 tanhDouble :: Double -> Double
479 expDouble :: Double -> Double
482 logDouble :: Double -> Double
485 powDouble :: Double -> Double -> Double
488 sqrtDouble :: Double -> Double
491 ceilDouble :: Double -> Double
494 floorDouble :: Double -> Double
497 roundDouble :: Double -> Long
500 absInteger :: Integer -> Integer
503 absLong :: Long -> Long
506 absFloat :: Float -> Float
509 absDouble :: Double -> Double
512 minInteger :: Integer -> Integer -> Integer
515 minLong :: Long -> Long -> Long
518 minFloat :: Float -> Float -> Float
521 minDouble :: Double -> Double -> Double
524 maxInteger :: Integer -> Integer -> Integer
527 maxLong :: Long -> Long -> Long
530 maxFloat :: Float -> Float -> Float
533 maxDouble :: Double -> Double -> Double
538 importJava "java.lang.Byte" where
540 showByte :: Byte -> String
543 readByte :: String -> Byte
545 instance Ord Byte where
551 instance Additive Byte where
552 zero = Java.i2b Java.iconst_0
555 instance Ring Byte where
558 one = Java.i2b Java.iconst_1
560 fromInteger = Java.i2b
562 instance Show Byte where
564 precedence v = if v >= 0 then 0 else 100
566 instance Read Byte where
571 importJava "java.lang.Short" where
573 showShort :: Short -> String
576 readShort :: String -> Short
578 instance Ord Short where
584 instance Additive Short where
588 instance Ring Short where
593 fromInteger = Java.i2s
595 instance Show Short where
597 precedence v = if v >= 0 then 0 else 100
599 instance Read Short where
605 importJava "java.lang.Integer" where
607 showInteger :: Integer -> String
610 readInteger :: String -> Integer
612 instance Ord Integer where
618 instance Additive Integer where
622 instance Ring Integer where
629 instance OrderedRing Integer where
633 instance Integral Integer where
637 instance Show Integer where
639 precedence v = if v >= 0 then 0 else 100
641 instance Read Integer where
647 importJava "java.lang.Long" where
649 showLong :: Long -> String
652 readLong :: String -> Long
654 instance Ord Long where
660 instance Additive Long where
664 instance Ring Long where
669 fromInteger = Java.i2l
671 instance OrderedRing Long where
675 instance Integral Long where
679 instance Show Long where
681 precedence v = if v >= 0 then 0 else 100
683 instance Read Long where
688 importJava "java.lang.Float" where
691 compareFloat :: Float -> Float -> Integer
695 showFloat :: Float -> String
699 readFloat :: String -> Float
701 "Converts 32-bit floating point number to a 32-bit integer with the same byte level representation."
702 floatToIntBits :: Float -> Integer
704 instance Ord Float where
705 compare = compareFloat
711 instance Additive Float where
715 instance Ring Float where
720 fromInteger = Java.i2f
722 instance OrderedRing Float where
726 instance Real Float where
728 x ^ y = Java.d2f (powDouble (Java.f2d x) (Java.f2d y))
729 pi = fromDouble piDouble
730 sqrt = Java.d2f . sqrtDouble . Java.f2d
731 exp = Java.d2f . expDouble . Java.f2d
732 log = Java.d2f . logDouble . Java.f2d
733 sin = Java.d2f . sinDouble . Java.f2d
734 cos = Java.d2f . cosDouble . Java.f2d
735 tan = Java.d2f . tanDouble . Java.f2d
736 asin = Java.d2f . asinDouble . Java.f2d
737 acos = Java.d2f . acosDouble . Java.f2d
738 atan = Java.d2f . atanDouble . Java.f2d
739 sinh = Java.d2f . sinhDouble . Java.f2d
740 cosh = Java.d2f . coshDouble . Java.f2d
741 tanh = Java.d2f . tanhDouble . Java.f2d
742 floor = Java.d2f . floorDouble . Java.f2d
743 ceil = Java.d2f . ceilDouble . Java.f2d
744 atan2 y x = Java.d2f (atan2Double (Java.f2d y) (Java.f2d x))
745 round = roundDouble . Java.f2d
746 fromDouble = Java.d2f
749 instance Show Float where
751 precedence v = if v >= 0 then 0 else 100
753 instance Read Float where
758 importJava "java.lang.Double" where
761 compareDouble :: Double -> Double -> Integer
765 showDouble :: Double -> String
768 @JavaName parseDouble
769 readDouble :: String -> Double
771 "Converts 64-bit floating point number to a 64-bit integer with the same byte level representation."
772 doubleToLongBits :: Double -> Long
774 isFinite :: Double -> Boolean
775 isNaN :: Double -> Boolean
776 isInfinite :: Double -> Boolean
778 instance Ord Double where
779 compare = compareDouble
785 instance Additive Double where
789 instance Ring Double where
794 fromInteger = Java.i2d
796 instance OrderedRing Double where
800 instance Real Double where
823 instance Show Double where
825 precedence v = if v >= 0 then 0 else 100
827 instance Read Double where
832 importJava "java.lang.Character" where
834 showCharacter :: Character -> String
836 "Returns true, if the given character is a letter."
837 isLetter :: Character -> Boolean
839 "Returns true, if the given character is a digit."
840 isDigit :: Character -> Boolean
842 instance Ord Character where
848 instance Show Character where
849 sb <+ c = sb << "'" << showCharacter c << "'"
851 "Adds a given integer to the character code."
852 addChar :: Character -> Integer -> Character
855 "Subtracts a given integer from the character code."
856 subChar :: Character -> Character -> Integer
862 The `Functor` class is used for types that can be mapped over. Instances of `Functor` should satisfy the following laws:
865 fmap (f . g) == fmap f . fmap g
867 class Functor f where
868 "Lifts a pure function to the given functor."
869 fmap :: (a -> b) -> f a -> f b
871 class CoFunctor f where
872 comap :: (a -> b) -> f b -> f a
876 class (Functor f) => Applicative f where
878 (<*>) :: f (a -> b) -> f a -> f b
879 (*>) :: f a -> f b -> f b
880 (<*) :: f a -> f b -> f a
882 u *> v = pure (const id) <*> u <*> v
883 u <* v = pure const <*> u <*> v
884 fmap f x = pure f <*> x
889 The `Monad` class defines the basic operations over a monad, a concept from a branch of mathematics known as category theory.
890 From the perspective of a SCL programmer, however, it is best to think of a monad as an abstract datatype of actions.
891 SCL's `mdo expressions provide a convenient syntax for writing monadic expressions.
893 Instances of `Monad` should satisfy the following laws:
895 return a >>= k == k a
897 m >>= (\x -> k x >>= h) == (m >>= k) >>= h
898 fmap f xs == xs >>= return . f
900 class (Functor m) => Monad m where
901 "Inject a value into the monadic type."
903 "Sequentially compose two actions, passing any value produced by the first as an argument to the second."
904 (>>=) :: m a -> (a -> m b) -> m b
906 The join function is the conventional monad join operator. It removes one level of monadic
909 For lists, `join` concatenates a list of lists:
911 join [[1,2], [3,4]] = [1, 2, 3, 4]
913 join :: m (m a) -> m a
917 Sequentially compose two actions, discarding any value produced by the first, like sequencing operators
918 (such as the semicolon) in imperative languages."
921 (>>) :: Monad m => m a -> m b -> m b
922 a >> b = a >>= (\_ -> b)
924 "Left-to-right Kleisli composition of monads."
925 (>=>) :: Monad m => (a -> m b) -> (b -> m c) -> (a -> m c)
926 (f >=> g) x = (f x) >>= g
928 "While loop. `while cond body` executes the `body` while the `cond` is true."
930 while :: (<e> Boolean) -> (<e> a) -> <e> ()
931 while cond body = loop ()
932 where loop _ = if cond
933 then do body ; loop ()
937 Sequences the given monadic value infinitely:
939 repeatForever m = m >> m >> m >> ...
941 repeatForever m = m >> repeatForever m
943 replicateM :: Monad m => Integer -> m a -> m [a]
944 replicateM count m = loop count emptyList
946 loop count l | count <= 0 = return l
949 loop (count-1) (addList l v)
951 replicateM_ :: Monad m => Integer -> m a -> m ()
952 replicateM_ count m | count <= 0 = return ()
953 | otherwise = m >> replicateM_ (count-1) m
958 A class of monads with zero element satisfying
962 class (Monad m) => MonadZero m where
965 "Injects a boolean test to a type beloning to `MonadZero`."
966 guard :: MonadZero m => Boolean -> m ()
967 guard True = return ()
973 A class of monads with associative binary operator `mplus` satisfying the following laws:
977 mplus (mplus a b) c = mplus a (mplus b c)
978 mplus a b >>= k = mplus (a >>= k) (b >>= k)
980 class (MonadZero m) => MonadPlus m where
981 mplus :: m a -> m a -> m a
986 A class of monads with associative binary operator `morelse` satisfying the following laws:
990 morelse (morelse a b) c = morelse a (morelse b c)
991 morelse (return a) b = return a
993 class (MonadZero m) => MonadOr m where
994 morelse :: m a -> m a -> m a
999 A class of types that can be mapped over with effectful mapping functions.
1001 class (Functor f) => FunctorE f where
1003 Applies the function to all elements of the container and
1004 returns the similarly shaped container with the results:
1008 map f [e1, e2, ..., eN] = [f e1, f e2, ..., f eN]
1012 map (*2) [1..5] = [2, 4, 6, 8, 10]
1014 map :: (a -> <e> b) -> f a -> <e> (f b)
1015 "Calls the given function with all elements of the given container."
1016 iter :: (a -> <e> b) -> f a -> <e> ()
1017 "Calls the given function with all elements of the given container giving also the index of the element as a parameter."
1018 iterI :: (Integer -> a -> <e> b) -> f a -> <e> ()
1020 "Iterates the elements of the given collection. Same as `iter` but parameters flipped."
1021 for :: FunctorE f => f a -> (a -> <e> b) -> <e> ()
1025 "Iterates the elements of the given collection providing also the indices of the elements. Same as `iterI` but parameters flipped."
1026 forI :: FunctorE f => f a -> (Integer -> a -> <e> b) -> <e> ()
1028 forI l f = iterI f l
1030 "`forN n f` calls `f` for all integers `0`, ..., `n-1`"
1032 forN :: Integer -> (Integer -> <e> b) -> <e> ()
1036 then do f i ; loop (i+1)
1040 mapI :: (Integer -> a -> <e> b) -> [a] -> <e> [b]
1041 mapI f l = build (\empty cons -> let
1043 loop i accum = if i < len
1044 then loop (i+1) (cons accum (f i (l!i)))
1049 `mapMaybe` combines `map` and `filter` functions.
1050 It applies the given function to every element of the input list. If the result
1051 is `Just x`, then `x` is added to the resulting list.
1053 mapMaybe f lst = [y | x <- lst, Just y = f x]
1056 mapMaybe :: (a -> <e> Maybe b) -> [a] -> <e> [b]
1057 mapMaybe f l = build (\empty cons -> foldl (\cur x -> match f x with Just v -> cons cur v ; _ -> cur) empty l)
1060 Applies the given function to all elements of the list. Produces two lists: the first contains all elements `x`
1061 for which the function returned `Left x` and the second list contains all elements `y` for which the function
1064 mapEither :: (a -> <e> Either b c) -> [a] -> <e> ([b], [c])
1065 mapEither f list = runProc do
1068 for list (\x -> match f x with
1069 Left v -> addArrayList l v
1070 Right v -> addArrayList r v)
1071 (Java.unsafeCoerce l, Java.unsafeCoerce r)
1073 "`replicate n v` returns a list of length `n` such that each element is a copy of `v`."
1075 replicate :: Integer -> a -> [a]
1076 replicate n v = build (\empty cons ->
1078 aux i l = aux (i-1) (cons l v)
1084 class (Functor f) => FunctorM f where
1085 "`mapM f` is equivalent to `sequence . map f`."
1086 mapM :: Monad m => (a -> m b) -> f a -> m (f b)
1087 "Evaluate each action in the sequence from left to right, and collect the results."
1088 sequence :: Monad m => f (m a) -> m (f a)
1089 mapM f l = sequence (fmap f l)
1093 "Identity function."
1098 Ignores the given value. This function is used in a situation where a function returns
1099 a value in a context where the value is not expected.
1106 ignoreM :: a -> Maybe b
1110 Composes two functions
1113 (.) :: (b -> <e> c) -> (a -> <e> b) -> (a -> <e> c)
1118 "A type class for sequences. All sequences must support indexing by integers."
1119 class /*(Additive a) =>*/ Sequence a where
1120 "Length of the sequence"
1121 length :: a -> Integer
1122 "`take n s` returns the first `n` elements of the sequence `s`."
1123 take :: Integer -> a -> a
1124 "`drop n s` removes the first `n` elements of the sequence `s`."
1125 drop :: Integer -> a -> a
1127 `sub s begin end` returns a subsequence of `s` starting from
1128 index `begin` and ending just before index `end`.
1130 sub :: a -> Integer -> Integer -> a
1132 take n v = sub v 0 (min n (length v))
1133 drop n v = sub v (min n len) len
1137 instance Sequence [a] where
1141 instance Sequence String where
1142 length = lengthString
1145 class IndexedSequence f where
1146 "`seq ! i` returns the `i`th element of the sequence `seq`. Indexing starts from zero."
1147 (!) :: f a -> Integer -> a
1149 instance IndexedSequence [] where
1155 Equivalent to the boolean value `True`. The value is meant to be used in
1162 otherwise :: Boolean
1165 instance Ord Boolean where
1166 compare False False = 0
1167 compare False True = neg 1
1168 compare True False = 1
1169 compare True True = 0
1171 instance Show Boolean where
1173 show False = "False"
1176 Boolean conjunction (and). The function is a macro that evaluates the second parameter
1177 only if the first parameter is `True`.
1180 <tr><th>a</th><th>b</th><th>a && b</th></tr>
1181 <tr><td>True</td><td>True</td><td>True</td></tr>
1182 <tr><td>True</td><td>False</td><td>False</td></tr>
1183 <tr><td>False</td><td>not evaluated</td><td>False</td></tr>
1187 (&&) :: Boolean -> Boolean -> Boolean
1188 a && b = if a then b else False
1191 Boolean disjunction (or). The function is a macro that evaluates the second parameter
1192 only if the first parameter is `False`.
1195 <tr><th>a</th><th>b</th><th>a || b</th></tr>
1196 <tr><td>True</td><td>not evaluated</td><td>True</td></tr>
1197 <tr><td>False</td><td>True</td><td>True</td></tr>
1198 <tr><td>False</td><td>False</td><td>False</td></tr>
1202 (||) :: Boolean -> Boolean -> Boolean
1203 a || b = if a then True else b
1207 not a = if a then False else True
1211 //data Maybe a = Nothing | Just a
1213 "Given `Just x` this function returns `x`. If the parameter is `Nothing`, the function raises an exception."
1214 fromJust :: Maybe a -> a
1215 fromJust (Just a) = a
1217 deriving instance (Ord a) => Ord (Maybe a)
1218 deriving instance (Show a) => Show (Maybe a)
1220 instance Functor Maybe where
1221 fmap _ Nothing = Nothing
1222 fmap f (Just x) = Just (f x)
1224 instance FunctorE Maybe where
1225 map _ Nothing = Nothing
1226 map f (Just x) = Just (f x)
1229 iter f (Just x) = ignore (f x)
1231 iterI _ Nothing = ()
1232 iterI f (Just x) = ignore (f 0 x)
1234 instance Monad Maybe where
1238 Nothing >>= _ = Nothing
1242 join Nothing = Nothing
1245 instance MonadZero Maybe where
1248 instance MonadOr Maybe where
1249 morelse a@(Just _) _ = a
1252 "`execJust v f` executes the function `f` with parameter value `x`, if `v=Just x`. If `v=Nothing`, the function does nothing."
1254 execJust :: Maybe a -> (a -> <e> b) -> <e> ()
1255 execJust maybeValue procedure = match maybeValue with
1256 Just v -> ignore $ procedure v
1259 "`fromMaybe def v` returns `def` if `v=Nothing` and `x` if `v=Just x`."
1261 fromMaybe :: a -> Maybe a -> a
1262 fromMaybe default maybeValue = match maybeValue with
1268 Provides a default value if the first parameter is Nothing.
1269 The default value is evaluated only if needed. The function
1270 can be used as an operator and is right associative so that
1271 the following is possible:
1273 tryWithTheFirstMethod
1274 `orElse` tryWithTheSecondMethod
1275 `orElse` fail "Didn't succeed."
1278 orElse :: Maybe a -> (<e> a) -> <e> a
1279 orElse (Just x) _ = x
1280 orElse Nothing def = def
1285 The Either type represents values with two possibilities: a value of type `Either a b` is either `Left a` or `Right b`.
1287 The `Either` type is sometimes used to represent a value which is either correct or an error; by convention, the `Left` constructor
1288 is used to hold an error value and the `Right` constructor is used to hold a correct value (mnemonic: "right" also means "correct").
1290 @JavaType "org.simantics.scl.runtime.either.Either"
1292 @JavaType "org.simantics.scl.runtime.either.Left"
1295 | @JavaType "org.simantics.scl.runtime.either.Right"
1299 deriving instance (Ord a, Ord b) => Ord (Either a b)
1300 deriving instance (Show a, Show b) => Show (Either a b)
1302 instance Functor (Either a) where
1303 fmap _ (Left x) = Left x
1304 fmap f (Right y) = Right (f y)
1306 instance FunctorE (Either a) where
1307 map _ (Left x) = Left x
1308 map f (Right y) = Right (f y)
1310 iter _ (Left x) = ()
1311 iter f (Right y) = ignore (f y)
1313 iterI _ (Left x) = ()
1314 iterI f (Right y) = ignore (f 0 y)
1316 instance Monad (Either b) where
1319 Left x >>= _ = Left x
1322 join (Left x) = Left x
1327 importJava "java.lang.String" where
1330 concatString :: String -> String -> String
1332 @JavaName "compareTo"
1333 compareString :: String -> String -> Integer
1336 lengthString :: String -> Integer
1339 `replaceString original pattern replacement` replaces all occurrences of `pattern` in the string by `replacement`.
1342 replaceString :: String -> String -> String -> String
1346 splitString_ :: String -> String -> Array String
1349 `indexOf string s` finds the first occurrence of `s` from `string` and returns its index.
1350 If the `s` does not occur in the string, return `-1`."
1353 indexOf :: String -> String -> Integer
1355 "Works like `indexOf` but starts searching from the given index instead of the beginning of the string."
1357 indexOfStartingFrom :: String -> String -> Integer -> Integer
1359 "Works like `indexOf` but returns the index of the last occurrence."
1360 @JavaName lastIndexOf
1361 lastIndexOf :: String -> String -> Integer
1363 "Works like `lastIndexOf` but starts searching from the given index instead of the end of the string."
1364 @JavaName lastIndexOf
1365 lastIndexOfStartingFrom :: String -> String -> Integer -> Integer
1369 subString :: String -> Integer -> Integer -> String
1372 `regionMatches str1 offset1 str2 offset2 len` tests whether
1373 `sub str1 offset1 (offset1+len) == sub str2 offset2 (offset2+len)`.
1375 regionMatches :: String -> Integer -> String -> Integer -> Integer -> Boolean
1377 "`startsWith string prefix` returns true if the string begins with the given prefix."
1378 startsWith :: String -> String -> Boolean
1380 "`endsWith string suffix` returns true if the string ends with the given prefix."
1381 endsWith :: String -> String -> Boolean
1383 "Removes leading and trailing whitespace from the string."
1384 trim :: String -> String
1386 "`contains string s` returns true if `string` contains `s` as a substring."
1387 contains :: String -> String -> Boolean
1389 "`charAt string i` returns the `i`th character of the string."
1390 charAt :: String -> Integer -> Character
1392 "Converts all letters of the string to lower case."
1393 toLowerCase :: String -> String
1394 "Converts all letters of the string to upper case."
1395 toUpperCase :: String -> String
1397 "Creates a string from a vector of characters."
1399 string :: Vector Character -> String
1401 instance Ord String where
1402 compare = compareString
1404 instance Additive String where
1407 sum ss = runProc (StringBuilder.toString $ foldl StringBuilder.appendString StringBuilder.new ss)
1410 importJava "org.simantics.scl.runtime.string.StringEscape" where
1411 appendEscapedString :: StringBuilder.T -> String -> <Proc> StringBuilder.T
1413 instance Show String where
1414 showForPrinting = id
1415 sb <+ v = (appendEscapedString (sb << "\"") v) << "\""
1417 instance Read String where
1420 @deprecated "Instead of 'splitString text pattern', write 'split pattern text' (note change in the parameter order)."
1421 "`splitString text pattern` splits the string into a list of string where the parts are sepratated in the original list by the given pattern."
1422 splitString :: String -> String -> [String]
1423 splitString source pattern = arrayToList $ splitString_ source pattern
1426 `split pattern text` splits `text` around matches of the given regular expression `pattern`.
1428 This function works as if by invoking the two-argument split method with the given expression and a limit argument of zero. Trailing empty strings are therefore not included in the resulting array.
1430 The string "boo:and:foo", for example, yields the following results with these expressions:
1433 : { "boo", "and", "foo" }
1434 o { "b", "", ":and:f" }
1436 split :: String -> String -> [String]
1437 split pattern text = arrayToList $ splitString_ text pattern
1441 instance Ord () where
1444 instance Additive () where
1448 instance Show () where
1453 "Gives the first element of a pair."
1458 "Gives the second element of a pair."
1463 instance (Ord a, Ord b) => Ord (a, b) where
1464 compare (a0, b0) (a1, b1) = compare a0 a1 &<& compare b0 b1
1466 instance (Additive a, Additive b) => Additive (a, b) where
1468 (a0, b0) + (a1, b1) = (a0+a1, b0+b1)
1470 instance Functor ((,) a) where
1471 fmap f (a,b) = (a, f b)
1473 instance (Show a, Show b) => Show (a, b) where
1474 sb <+ (x, y) = sb << "(" <+ x << ", " <+ y << ")"
1478 instance (Ord a, Ord b, Ord c) => Ord (a, b, c) where
1479 compare (a0, b0, c0) (a1, b1, c1) = compare a0 a1 &<& compare b0 b1 &<& compare c0 c1
1481 instance (Additive a, Additive b, Additive c) => Additive (a, b, c) where
1482 zero = (zero, zero, zero)
1483 (a0, b0, c0) + (a1, b1, c1) = (a0+a1, b0+b1, c0+c1)
1485 instance Functor ((,,) a b) where
1486 fmap f (a,b,c) = (a, b, f c)
1488 instance (Show a, Show b, Show c) => Show (a, b, c) where
1489 sb <+ (x, y, z) = sb << "(" <+ x << ", " <+ y << ", " <+ z << ")"
1493 instance (Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d) where
1494 compare (a0, b0, c0, d0) (a1, b1, c1, d1) =
1495 compare a0 a1 &<& compare b0 b1 &<& compare c0 c1 &<& compare d0 d1
1497 instance (Additive a, Additive b, Additive c, Additive d) => Additive (a, b, c, d) where
1498 zero = (zero, zero, zero, zero)
1499 (a0, b0, c0, d0) + (a1, b1, c1, d1) = (a0+a1, b0+b1, c0+c1, d0+d1)
1501 instance Functor ((,,,) a b c) where
1502 fmap f (a,b,c,d) = (a, b, c, f d)
1504 instance (Show a, Show b, Show c, Show d) => Show (a, b, c, d) where
1505 sb <+ (x, y, z, w) = sb << "(" <+ x << ", " <+ y << ", " <+ z << ", " <+ w << ")"
1509 instance (Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e) where
1510 compare (a0, b0, c0, d0, e0) (a1, b1, c1, d1, e1) =
1511 compare a0 a1 &<& compare b0 b1 &<& compare c0 c1 &<& compare d0 d1 &<& compare e0 e1
1513 instance (Additive a, Additive b, Additive c, Additive d, Additive e) => Additive (a, b, c, d, e) where
1514 zero = (zero, zero, zero, zero, zero)
1515 (a0, b0, c0, d0, e0) + (a1, b1, c1, d1, e1) = (a0+a1, b0+b1, c0+c1, d0+d1, e0+e1)
1517 instance Functor ((,,,,) a b c d) where
1518 fmap f (a,b,c,d,e) = (a, b, c, d, f e)
1522 instance (Ord a) => Ord [a] where
1523 compare a b = loop 0
1528 then (if i >= lB then 0 else -1)
1531 else compare (a!i) (b!i) &<& loop (i+1)
1533 instance Functor [] where
1536 instance FunctorE [] where
1541 instance Monad [] where
1542 return x = singletonList x
1543 l >>= f = concatMap f l
1546 instance MonadZero [] where
1549 instance MonadPlus [] where
1552 instance Additive [a] where
1556 instance FunctorM [] where
1557 sequence = foldl (\m mel -> m >>= \l -> mel >>= \el -> return (addList l el)) (return emptyList)
1558 mapM f l = sequence (map f l)
1560 "Appends the string representations of all elements of the list to the string builder and separates the values with the given separator."
1561 printWithSeparator :: Show a => StringBuilder.T -> String -> [a] -> <Proc> StringBuilder.T
1562 printWithSeparator sb sep l = loop 0
1565 loop i = if i >= len then sb
1567 (if i==0 then sb else sb << sep) <+ l!i
1571 Joins the string representations of the list of values with the given separator.
1573 See [intercalate](#intercalate) for an alternative that works with Strings
1574 and doesn't escape its arguments.
1576 joinWithSeparator :: Show a => String -> [a] -> String
1577 joinWithSeparator separator values = runProc (
1578 StringBuilder.toString $ printWithSeparator StringBuilder.new separator values)
1582 The intercalate function takes a String and a list of Strings
1583 and concatenates the list after interspersing the first argument
1584 between each element of the list.
1586 See also more generic [joinWithSeparator](#joinWithSeparator)
1587 which escapes its arguments using `show`.
1589 intercalate :: String -> [String] -> String
1590 intercalate separator strings = do
1597 sb = StringBuilder.new
1599 loop i | i == l = ()
1601 sb << separator << strings!i
1604 StringBuilder.toString sb
1606 instance (Show a) => Show [a] where
1611 if (i>0) then sb << ", " else sb
1618 importJava "java.util.List" where
1619 "`getList l i` returns the `i`th element of the list `l`. Indexing starts from zero. You can also use the `!` infix function for this purpose."
1621 getList :: [a] -> Integer -> a
1625 lengthList :: [a] -> Integer
1628 subList :: [a] -> Integer -> Integer -> [a]
1631 isEmpty :: [a] -> Boolean
1634 importJava "java.util.Collections" where
1636 //singletonList :: a -> [a]
1641 emptyList = build (\empty cons -> empty)
1644 "Creates a list with exectly one element."
1646 singletonList :: a -> [a]
1647 singletonList v = build (\empty cons -> cons empty v)
1650 // foldl f i (a + b) = foldl f (foldl f i a) b
1652 appendList :: [a] -> [a] -> [a]
1653 appendList a b = build (\empty cons -> foldl cons (foldl cons empty a) b)
1656 importJava "org.simantics.scl.runtime.list.ShareableList" where
1657 "Concatenates two lists."
1660 appendList :: [a] -> [a] -> [a]
1662 "Adds the given value to the end of the list."
1664 addList :: [a] -> a -> [a]
1667 importJava "java.util.ArrayList" where
1671 newArrayList :: <Proc> ArrayList a
1674 addArrayList :: ArrayList a -> a -> <Proc> ()
1677 A primitive for constructing a list by `empty` and `cons` operations given to the function given as a parameter to this function.
1680 build (\empty cons -> cons (cons (cons empty 1) 2) 3)
1686 The SCL compiler makes the following optimization when encountering `build` and `foldl` functions after inlining:
1688 foldl f i (build g) = g i f
1691 build :: forall b e2. (forall a e1. a -> (a -> b -> <e1> a) -> <e1,e2> a) -> <e2> [b]
1692 build f = runProc do
1694 f () (\_ v -> addArrayList l v)
1697 "A specific implementation of `map` for lists."
1700 mapEList :: (a -> <e> b) -> [a] -> <e> [b]
1701 mapEList f l = build (\empty cons -> foldl (\cur x -> cons cur (f x)) empty l)
1703 "A specific implementation of `fmap` for lists."
1705 mapList :: (a -> b) -> [a] -> [b]
1706 mapList f l = build (\empty cons -> foldl (\cur x -> cons cur (f x)) empty l)
1708 "`guardList v` returns a singleton `[()]` if `v=True` and the empty list if `v=False`."
1710 guardList :: Boolean -> [()]
1711 guardList cond = build (\empty cons -> if cond then cons empty () else empty)
1714 `concatMap` combines `map` and `join` functions.
1715 It maps the elements of a given list to lists with the given function and concatenates the results.
1717 concatMap f lst = join (map f lst) = [y | x <- lst, y <- f x]
1720 concatMap :: (a -> <e> [b]) -> [a] -> <e> [b]
1721 concatMap f l = build (\empty cons -> foldl (\cur le -> foldl cons cur (f le)) empty l)
1724 Applies the given function to the elements of the lists until the function returns something
1725 else than `Nothing`. This return value is also returned as a result of this function.
1728 mapFirst :: (a -> <e> Maybe b) -> [a] -> <e> Maybe b
1729 mapFirst f l = loop 0
1732 loop i = if i == len
1734 else match f (l!i) with
1736 Nothing -> loop (i+1)
1739 foldl op initialValue list
1741 applies a binary operator `op` to all elements of `list` from left to right
1742 starting with `initialValue`. For example,
1744 foldl op init [x1, x2, x3, x4] = (((init `op` x1) `op` x2) `op` x3) `op` x4
1747 foldl :: forall a b e. (a -> b -> <e> a) -> a -> [b] -> <e> a
1748 foldl f initial l = loop initial 0
1751 loop cur i = if i==len
1753 else loop (f cur (l!i)) (i+1)
1755 foldlI :: forall a b e. (Integer -> a -> b -> <e> a) -> a -> [b] -> <e> a
1756 foldlI f initial l = loop initial 0
1759 loop cur i = if i==len
1761 else loop (f i cur (l!i)) (i+1)
1763 scanl :: (b -> a -> <e> b) -> b -> [a] -> <e> [b]
1764 scanl f initial l = build (\empty cons -> let
1766 loop cur i accum = let nl = cons accum cur
1769 else loop (f cur (l!i)) (i+1) nl
1770 in loop initial 0 empty)
1772 "`foldr` is defined like `foldl` but it process the list from right to left."
1774 foldr :: (b -> a -> <e> a) -> a -> [b] -> <e> a
1775 foldr f initial l = loop initial (length l - 1)
1777 loop cur i = if i < 0
1779 else loop (f (l!i) cur) (i-1)
1781 foldr1 :: (a -> a -> <e> a) -> [a] -> <e> a
1782 foldr1 f l = loop (l!(len-1)) (len-2)
1785 loop cur i = if i < 0
1787 else loop (f (l!i) cur) (i-1)
1790 `filter pred lst` returns those elements of `lst` that the predicate `pred` accepts. For example
1792 filter (> 3) [1, 2, 3, 4, 5, 6] = [4, 5, 6]
1795 filter :: (a -> <e> Boolean) -> [a] -> <e> [a]
1796 filter p l = build (\empty cons -> foldl (\cur x -> if p x then cons cur x else cur) empty l)
1799 Takes those elements of the input list that match `(Just x)` and adds the contents to the resulting list. For example,
1801 filterJust [Just 1, Nothing, Just 5] = [1, 5]
1804 filterJust :: [Maybe a] -> [a]
1805 filterJust l = build (\empty cons -> foldl (\cur x -> match x with Just v -> cons cur v ; _ -> cur) empty l)
1807 listToMaybe :: [a] -> Maybe a
1808 listToMaybe l = if isEmpty l then Nothing else Just (l!0)
1810 maybeToList :: Maybe a -> [a]
1811 maybeToList (Just a) = [a]
1815 `takeWhile p l`, returns the longest prefix (possibly empty) of list `l` of elements that satisfy `p`
1817 takeWhile :: (a -> <e> Boolean) -> [a] -> <e> [a]
1818 takeWhile f l = loop 0
1821 loop i | i == len = l
1822 | f (l!i) = loop (i+1)
1823 | otherwise = take i l
1825 partition :: (a -> <e> Boolean) -> [a] -> <e> ([a], [a])
1826 partition p l = runProc do
1831 then addArrayList res1 el
1832 else addArrayList res2 el
1834 (Java.unsafeCoerce res1, Java.unsafeCoerce res2)
1837 `range begin end` produces a list of consecutive integers starting from `begin` and ending to `end` (including `end`).
1838 The compiler supports syntactic sugar `[begin..end]` for this function.
1841 range :: Integer -> Integer -> [Integer]
1842 range first last = build (\empty cons -> do
1843 loop i cur = if i > last then cur else loop (i+1) (cons cur i)
1846 "A specific implementation of `iter` for lists."
1848 iterList :: (a -> <e> b) -> [a] -> <e> ()
1849 iterList f l = foldl (\_ x -> ignore (f x)) () l
1851 "A specific implementation of `iterI` for lists."
1853 iterIList :: (Integer -> a -> <e> b) -> [a] -> <e> ()
1854 iterIList f l = do foldl (\i x -> do f i x ; i+1) 0 l ; ()
1857 Generates a list from a given starting state and iteration function.
1860 let nextState 0 = Nothing
1861 nextState i = Just (i, i `div` 2)
1862 in unfoldr nextState 30
1869 unfoldr :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1870 unfoldr f s = build (\empty cons -> do
1873 Just (el,newS) -> loop newS (cons cur el)
1877 importJava "org.simantics.scl.runtime.Lists" where
1881 mapList :: (a -> b) -> [a] -> [b]
1884 mapEList :: (a -> <e> b) -> [a] -> <e> [b]
1887 iterList :: (a -> <e> ()) -> [a] -> <e> ()
1888 concatMap :: (a -> <e> [b]) -> [a] -> <e> [b]
1891 Combines two lists into one list of pairs. The length of the resulting list is the length of the smallest input list.
1893 zip [1, 2, 3, 4, 5] ['a', 'b', 'c'] = [(1, 'a'), (2, 'b'), (3, 'c')]
1895 zip :: [a] -> [b] -> [(a,b)]
1896 "Combines two lists by using the given function for combining the elements. The length of the resulting list is the length of the smallest input list."
1897 zipWith :: (a -> b -> <e> c) -> [a] -> [b] -> <e> [c]
1899 Produces two lists from one list of pairs.
1901 unzip [(1, 'a'), (2, 'b'), (3, 'c')] = ([1, 2, 3], ['a', 'b', 'c'])
1903 unzip :: [(a,b)] -> ([a],[b])
1905 //"@filter p l@ returns those elements of @l@ that the predicate @p@ accepts."
1906 //filter :: (a -> <e> Boolean) -> [a] -> <e> [a]
1907 //filterJust :: [Maybe a] -> [a]
1909 foldl :: (a -> b -> <e> a) -> a -> [b] -> <e> a
1911 "Like `foldl` but assumes that the list is non-empty so the initial is not needed."
1912 foldl1 :: (a -> a -> <e> a) -> [a] -> <e> a
1913 //unfoldr :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1915 "Sorts the list using the given comparator."
1916 sortWith :: (a -> a -> <e> Integer) -> [a] -> <e> [a]
1917 "Works like `index` but uses the given functions as hash codes and equality."
1918 indexWith :: (a -> Integer) -> (a -> a -> Boolean) -> [(a,b)] -> a -> Maybe b
1919 groupWith :: (b -> Integer) -> (b -> b -> Boolean) -> (a -> <e> b) -> (a -> <e> c) -> [a] -> <e> [(b, [c])]
1920 "Works like `unique` but uses the given function for equality tests."
1921 uniqueWith :: (a -> a -> Boolean) -> [a] -> [a]
1922 "Works like `\\\\` but uses the given function for equality tests."
1923 deleteAllBy :: (a -> a -> Boolean) -> [a] -> [a] -> [a]
1925 //range :: Integer -> Integer -> [Integer]
1927 //build :: (forall a. a -> (a -> b -> <e> a) -> <e> a) -> <e> [b]
1929 "`elem el lst` return true, if `el` occurs in the list `lst`."
1930 elem :: a -> [a] -> Boolean
1934 loop i | i < len = if el == l!i
1939 "`elemMaybe v1 (Just v2)` returns true if `v1 == v2`. `elemMaybe v1 Nothing` is always false."
1940 elemMaybe :: a -> Maybe a -> Boolean
1941 elemMaybe el m = match m with
1942 Just el2 -> el == el2
1946 Computes a list that contains only elements that belongs to both input lists.
1948 intersect :: [a] -> [a] -> [a]
1949 intersect a b = filter f a
1953 "Reverses a given list. For example, `reverse [1,2,3] = [3,2,1]`"
1954 reverse :: [a] -> [a]
1955 reverse l = [l!(len-i) | i <- [1..len]]
1960 Transposes the rows and columns of its argument. For example,
1962 transpose [[1,2,3],[4,5,6]] == [[1,4],[2,5],[3,6]]
1963 transpose [[1,2],[3,4,5]] == [[1,3],[2,4],[5]]
1965 transpose xss = [[xs!i | xs <- xss, i < length xs]
1966 | i <- [0..maximum [length xs | xs <- xss]-1]]
1968 "Works like `unfoldr` but generates the list from right to left."
1969 unfoldl :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1970 unfoldl f seed = reverse $ unfoldr f seed
1972 "Removes the first element of the list, if the list is non-empty."
1974 tail l = if len < 2 then emptyList else subList l 1 len
1978 "Tries to find the given key from the list of key-value pairs and returns the corresponding value."
1979 lookup :: a -> [(a, b)] -> Maybe b
1984 (a,b) | a == el -> Just b
1985 | otherwise -> loop (i+1)
1989 "Conjunction over a list."
1991 and :: [Boolean] -> Boolean
1992 and = foldl (&&) True
1994 "Disjunction over a list."
1996 or :: [Boolean] -> Boolean
1997 or = foldl (||) False
2000 `any pred lst` tests whether the predicate `pred` holds some element of `lst`.
2001 It returns immediately when it encounters the first value satisfying the predicate.
2003 any :: (a -> <e> Boolean) -> [a] -> <e> Boolean
2007 `all pred lst` tests whether the predicate `pred` holds for all elements of `lst`.
2008 It returns immediately when it encounters the first value not satisfying the predicate.
2010 all :: (a -> <e> Boolean) -> [a] -> <e> Boolean
2014 Returns the first element of the list satisfying the given condition,
2015 or `Nothing` if there is no such element.
2017 findFirst :: (a -> <e> Boolean) -> [a] -> <e> Maybe a
2018 findFirst p l = loop 0
2022 then let el = l!i in
2031 Sorts the given list using its default order.
2034 sort :: Ord a => [a] -> [a]
2035 sort = sortWith compare
2038 Sorts the lists by the values computed by the first function.
2041 sortBy snd [(1,5), (2,3), (3,4)] = [(2,3), (3,4), (1,5)]
2044 sortBy :: Ord b => (a -> <e> b) -> [a] -> <e> [a]
2045 sortBy f l = sortWith (\x y -> compare (f x) (f y)) l
2046 // This is faster if f is slow, but will generate more auxiliary structures
2047 //sortBy f l = map snd (sortWith (\(x,_) (y,_) -> compare x y) [(f x, x) | x <- l])
2050 Given a list of key-value pairs, the function produces a function that finds a value
2051 efficiently for the given key.
2053 index :: [(a,b)] -> a -> Maybe b
2054 index = indexWith hashCode (==)
2057 Given a list of values and a function computing a key for each value, the function produces a function that finds a value
2058 effeciently for the given key.
2060 indexBy :: (a -> b) -> [a] -> b -> Maybe a
2061 indexBy f l = index [(f x, x) | x <- l]
2063 "Groups a list values by a key computed by the given function."
2064 groupBy :: (a -> <e> b) -> [a] -> <e> [(b, [a])]
2065 groupBy f l = groupWith hashCode (==) f id l
2067 "Groups a list of key-value pairs by the keys."
2068 group :: [(a,b)] -> [(a, [b])]
2069 group = groupWith hashCode (==) fst snd
2071 "Removes duplicates (all but the first occurrence) from the list but otherwise preserves the order of the elements."
2072 unique :: [a] -> [a]
2073 unique = uniqueWith (==)
2075 "Like `unique`, but uses the given function for finding the key values used for uniqueness testing."
2076 uniqueBy :: (a -> b) -> [a] -> [a]
2077 uniqueBy f = uniqueWith (\a b -> f a == f b)
2079 //sortAndUniqueBy :: Ord b => (a -> b) -> [a] -> [a]
2080 //sortAndUniqueBy f = map snd . uniqueWith (\a b -> fst a == fst b) . sortBy fst . map (\x -> (f x, x))
2082 "`a \\\\ b` removes all elements of `b` from the list `a`."
2083 (\\) :: [a] -> [a] -> [a]
2084 (\\) = deleteAllBy (==)
2088 importJava "java.lang.Object" where
2089 "A data type that can represent any value."
2094 showDynamic :: Dynamic -> String
2096 instance Show Dynamic where
2099 "Converts a value to `Dynamic` type."
2100 toDynamic :: a -> Dynamic
2101 toDynamic = Java.unsafeCoerce
2103 "Converts a `Dynamic` value to a required value, or fails if the conversion is not possible."
2104 importJava "org.simantics.scl.compiler.runtime.ValueConversion" where
2105 fromDynamic :: Typeable a => Dynamic -> a
2109 importJava "org.simantics.scl.runtime.procedure.Ref" where
2110 "A mutable reference to a value of type `a`."
2113 "Creates a new reference with the given initial value."
2115 ref :: a -> <Proc> (Ref a)
2117 "Returns the current value of the reference."
2119 getRef :: Ref a -> <Proc> a
2121 "Sets a new value for the reference."
2122 @JavaName "<set>value"
2123 (:=) :: Ref a -> a -> <Proc> ()
2125 instance Show (Ref a) where
2126 show _ = "<reference>"
2128 importJava "org.simantics.scl.runtime.reporting.SCLReporting" where
2129 "Prints the given string to the console."
2131 printString :: String -> <Proc> ()
2132 "Prints an error message to the console."
2133 printError :: String -> <Proc> ()
2134 "Reports that certain amount of work has been done for the current task."
2135 didWork :: Double -> <Proc> ()
2137 `printingToFile "fileName" expression` executes the `expression` so that all its console prints
2138 are written to the file given as a first parameter.
2140 printingToFile :: String -> (<e> a) -> <e> a
2142 `printErrorsAsNormalPrints expression` executes the `expression` so that all its error prints
2143 are printed as normal prints. This is useful mainly in testing scripts for checking that the implementations
2144 give proper error messages with invalid inputs.
2146 printErrorsAsNormalPrints :: (<e> a) -> <e> a
2148 `disablePrintingForCommand expression` executes the `expression` so that it does not print return values.
2149 Errors are printed normally.
2151 disablePrintingForCommand :: (<e> a) -> <e> a
2154 importJava "org.simantics.scl.runtime.procedure.Procedures" where
2155 "Returns `True` if the current thread has been interrupted."
2156 isInterrupted :: <Proc> Boolean
2157 "Checks whether the current thread has been interrupted and throws an exception if it is."
2158 checkInterrupted :: <Proc> ()
2159 "Generates a random identifier."
2160 generateUID :: <Proc> String
2162 "Executes the given expression and catches certain class of exceptions (specified by the catch handler that is given as a second parameter.)"
2164 catch :: VecComp ex => (<e,Exception> a) -> (ex -> <e> a) -> <e> a
2166 importJava "java.lang.Throwable" where
2170 showThrowable :: Throwable -> String
2171 importJava "java.lang.Exception" where
2175 showException :: Exception -> String
2177 instance Show Throwable where
2178 show = showThrowable
2179 instance Show Exception where
2180 show = showException
2182 "Prints the given value in the console."
2184 print :: Show a => a -> <Proc> ()
2185 print v = printString (showForPrinting v)
2187 instance Show TypeRep where
2188 sb <+ (TApply (TCon "Builtin" "[]") b) =
2189 sb << "[" <+ b << "]"
2190 sb <+ (TApply (TApply (TCon "Builtin" "(,)") c1) c2) =
2191 sb << "(" <+ c1 << "," <+ c2 << ")"
2192 sb <+ (TApply (TApply (TApply (TCon "Builtin" "(,,)") c1) c2) c3) =
2193 sb << "(" <+ c1 << "," <+ c2 << "," <+ c3 << ")"
2194 sb <+ (TApply (TApply (TApply (TApply (TCon "Builtin" "(,,,)") c1) c2) c3) c4) =
2195 sb << "(" <+ c1 << "," <+ c2 << "," <+ c3 << "," <+ c4 << ")"
2197 sb <+ (TCon _ name) = sb << name
2198 sb <+ (TApply a b) = sb <+ Par 1 a << " " <+ Par 2 b
2199 sb <+ (TFun a b) = sb <+ Par 1 a << " -> " <+ b
2201 precedence (TCon _ _) = 0
2202 precedence (TFun _ _) = 2
2203 precedence (TApply a _) = if isSpecialType a then 0 else 1
2205 isSpecialType (TCon "Builtin" "[]") = True
2206 isSpecialType (TCon "Builtin" "()") = True
2207 isSpecialType (TCon "Builtin" "(,)") = True
2208 isSpecialType (TCon "Builtin" "(,,)") = True
2209 isSpecialType (TCon "Builtin" "(,,,)") = True
2210 isSpecialType (TApply a _) = isSpecialType a
2215 importJava "java.util.Arrays" where
2218 byteArrayToString :: ByteArray -> String
2220 instance Show ByteArray where
2221 show = byteArrayToString
2226 importJava "org.simantics.scl.compiler.types.Type" where
2228 showType :: Type -> String
2230 importJava "org.simantics.scl.compiler.types.Types" where
2231 removeForAll :: Type -> Type
2233 instance Show Type where