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 "While loop. `while cond body` executes the `body` while the `cond` is true."
926 while :: (<e> Boolean) -> (<e> a) -> <e> ()
927 while cond body = loop ()
928 where loop _ = if cond
929 then do body ; loop ()
933 Sequences the given monadic value infinitely:
935 repeatForever m = m >> m >> m >> ...
937 repeatForever m = m >> repeatForever m
939 replicateM :: Monad m => Integer -> m a -> m [a]
940 replicateM count m = loop count emptyList
942 loop count l | count <= 0 = return l
945 loop (count-1) (addList l v)
947 replicateM_ :: Monad m => Integer -> m a -> m ()
948 replicateM_ count m | count <= 0 = return ()
949 | otherwise = m >> replicateM_ (count-1) m
954 A class of monads with zero element satisfying
958 class (Monad m) => MonadZero m where
961 "Injects a boolean test to a type beloning to `MonadZero`."
962 guard :: MonadZero m => Boolean -> m ()
963 guard True = return ()
969 A class of monads with associative binary operator `mplus` satisfying the following laws:
973 mplus (mplus a b) c = mplus a (mplus b c)
974 mplus a b >>= k = mplus (a >>= k) (b >>= k)
976 class (MonadZero m) => MonadPlus m where
977 mplus :: m a -> m a -> m a
982 A class of monads with associative binary operator `morelse` satisfying the following laws:
986 morelse (morelse a b) c = morelse a (morelse b c)
987 morelse (return a) b = return a
989 class (MonadZero m) => MonadOr m where
990 morelse :: m a -> m a -> m a
995 A class of types that can be mapped over with effectful mapping functions.
997 class (Functor f) => FunctorE f where
999 Applies the function to all elements of the container and
1000 returns the similarly shaped container with the results:
1004 map f [e1, e2, ..., eN] = [f e1, f e2, ..., f eN]
1008 map (*2) [1..5] = [2, 4, 6, 8, 10]
1010 map :: (a -> <e> b) -> f a -> <e> (f b)
1011 "Calls the given function with all elements of the given container."
1012 iter :: (a -> <e> b) -> f a -> <e> ()
1013 "Calls the given function with all elements of the given container giving also the index of the element as a parameter."
1014 iterI :: (Integer -> a -> <e> b) -> f a -> <e> ()
1016 "Iterates the elements of the given collection. Same as `iter` but parameters flipped."
1017 for :: FunctorE f => f a -> (a -> <e> b) -> <e> ()
1021 "Iterates the elements of the given collection providing also the indices of the elements. Same as `iterI` but parameters flipped."
1022 forI :: FunctorE f => f a -> (Integer -> a -> <e> b) -> <e> ()
1024 forI l f = iterI f l
1026 "`forN n f` calls `f` for all integers `0`, ..., `n-1`"
1028 forN :: Integer -> (Integer -> <e> b) -> <e> ()
1032 then do f i ; loop (i+1)
1036 mapI :: (Integer -> a -> <e> b) -> [a] -> <e> [b]
1037 mapI f l = build (\empty cons -> let
1039 loop i accum = if i < len
1040 then loop (i+1) (cons accum (f i (l!i)))
1045 `mapMaybe` combines `map` and `filter` functions.
1046 It applies the given function to every element of the input list. If the result
1047 is `Just x`, then `x` is added to the resulting list.
1049 mapMaybe f lst = [y | x <- lst, Just y = f x]
1052 mapMaybe :: (a -> <e> Maybe b) -> [a] -> <e> [b]
1053 mapMaybe f l = build (\empty cons -> foldl (\cur x -> match f x with Just v -> cons cur v ; _ -> cur) empty l)
1056 Applies the given function to all elements of the list. Produces two lists: the first contains all elements `x`
1057 for which the function returned `Left x` and the second list contains all elements `y` for which the function
1060 mapEither :: (a -> <e> Either b c) -> [a] -> <e> ([b], [c])
1061 mapEither f list = runProc do
1064 for list (\x -> match f x with
1065 Left v -> addArrayList l v
1066 Right v -> addArrayList r v)
1067 (Java.unsafeCoerce l, Java.unsafeCoerce r)
1069 "`replicate n v` returns a list of length `n` such that each element is a copy of `v`."
1071 replicate :: Integer -> a -> [a]
1072 replicate n v = build (\empty cons ->
1074 aux i l = aux (i-1) (cons l v)
1080 class (Functor f) => FunctorM f where
1081 "`mapM f` is equivalent to `sequence . map f`."
1082 mapM :: Monad m => (a -> m b) -> f a -> m (f b)
1083 "Evaluate each action in the sequence from left to right, and collect the results."
1084 sequence :: Monad m => f (m a) -> m (f a)
1085 mapM f l = sequence (fmap f l)
1089 "Identity function."
1094 Ignores the given value. This function is used in a situation where a function returns
1095 a value in a context where the value is not expected.
1102 ignoreM :: a -> Maybe b
1106 Composes two functions
1109 (.) :: (b -> <e> c) -> (a -> <e> b) -> (a -> <e> c)
1114 "A type class for sequences. All sequences must support indexing by integers."
1115 class /*(Additive a) =>*/ Sequence a where
1116 "Length of the sequence"
1117 length :: a -> Integer
1118 "`take n s` returns the first `n` elements of the sequence `s`."
1119 take :: Integer -> a -> a
1120 "`drop n s` removes the first `n` elements of the sequence `s`."
1121 drop :: Integer -> a -> a
1123 `sub s begin end` returns a subsequence of `s` starting from
1124 index `begin` and ending just before index `end`.
1126 sub :: a -> Integer -> Integer -> a
1128 take n v = sub v 0 (min n (length v))
1129 drop n v = sub v (min n len) len
1133 instance Sequence [a] where
1137 instance Sequence String where
1138 length = lengthString
1141 class IndexedSequence f where
1142 "`seq ! i` returns the `i`th element of the sequence `seq`. Indexing starts from zero."
1143 (!) :: f a -> Integer -> a
1145 instance IndexedSequence [] where
1151 Equivalent to the boolean value `True`. The value is meant to be used in
1158 otherwise :: Boolean
1161 instance Ord Boolean where
1162 compare False False = 0
1163 compare False True = neg 1
1164 compare True False = 1
1165 compare True True = 0
1167 instance Show Boolean where
1169 show False = "False"
1172 Boolean conjunction (and). The function is a macro that evaluates the second parameter
1173 only if the first parameter is `True`.
1176 <tr><th>a</th><th>b</th><th>a && b</th></tr>
1177 <tr><td>True</td><td>True</td><td>True</td></tr>
1178 <tr><td>True</td><td>False</td><td>False</td></tr>
1179 <tr><td>False</td><td>not evaluated</td><td>False</td></tr>
1183 (&&) :: Boolean -> Boolean -> Boolean
1184 a && b = if a then b else False
1187 Boolean disjunction (or). The function is a macro that evaluates the second parameter
1188 only if the first parameter is `False`.
1191 <tr><th>a</th><th>b</th><th>a || b</th></tr>
1192 <tr><td>True</td><td>not evaluated</td><td>True</td></tr>
1193 <tr><td>False</td><td>True</td><td>True</td></tr>
1194 <tr><td>False</td><td>False</td><td>False</td></tr>
1198 (||) :: Boolean -> Boolean -> Boolean
1199 a || b = if a then True else b
1203 not a = if a then False else True
1207 //data Maybe a = Nothing | Just a
1209 "Given `Just x` this function returns `x`. If the parameter is `Nothing`, the function raises an exception."
1210 fromJust :: Maybe a -> a
1211 fromJust (Just a) = a
1213 deriving instance (Ord a) => Ord (Maybe a)
1214 deriving instance (Show a) => Show (Maybe a)
1216 instance Functor Maybe where
1217 fmap _ Nothing = Nothing
1218 fmap f (Just x) = Just (f x)
1220 instance FunctorE Maybe where
1221 map _ Nothing = Nothing
1222 map f (Just x) = Just (f x)
1225 iter f (Just x) = ignore (f x)
1227 iterI _ Nothing = ()
1228 iterI f (Just x) = ignore (f 0 x)
1230 instance Monad Maybe where
1234 Nothing >>= _ = Nothing
1238 join Nothing = Nothing
1241 instance MonadZero Maybe where
1244 instance MonadOr Maybe where
1245 morelse a@(Just _) _ = a
1248 "`execJust v f` executes the function `f` with parameter value `x`, if `v=Just x`. If `v=Nothing`, the function does nothing."
1250 execJust :: Maybe a -> (a -> <e> b) -> <e> ()
1251 execJust maybeValue procedure = match maybeValue with
1252 Just v -> ignore $ procedure v
1255 "`fromMaybe def v` returns `def` if `v=Nothing` and `x` if `v=Just x`."
1257 fromMaybe :: a -> Maybe a -> a
1258 fromMaybe default maybeValue = match maybeValue with
1264 Provides a default value if the first parameter is Nothing.
1265 The default value is evaluated only if needed. The function
1266 can be used as an operator and is right associative so that
1267 the following is possible:
1269 tryWithTheFirstMethod
1270 `orElse` tryWithTheSecondMethod
1271 `orElse` fail "Didn't succeed."
1274 orElse :: Maybe a -> (<e> a) -> <e> a
1275 orElse (Just x) _ = x
1276 orElse Nothing def = def
1281 The Either type represents values with two possibilities: a value of type `Either a b` is either `Left a` or `Right b`.
1283 The `Either` type is sometimes used to represent a value which is either correct or an error; by convention, the `Left` constructor
1284 is used to hold an error value and the `Right` constructor is used to hold a correct value (mnemonic: "right" also means "correct").
1286 @JavaType "org.simantics.scl.runtime.either.Either"
1288 @JavaType "org.simantics.scl.runtime.either.Left"
1291 | @JavaType "org.simantics.scl.runtime.either.Right"
1295 deriving instance (Ord a, Ord b) => Ord (Either a b)
1296 deriving instance (Show a, Show b) => Show (Either a b)
1298 instance Functor (Either a) where
1299 fmap _ (Left x) = Left x
1300 fmap f (Right y) = Right (f y)
1302 instance FunctorE (Either a) where
1303 map _ (Left x) = Left x
1304 map f (Right y) = Right (f y)
1306 iter _ (Left x) = ()
1307 iter f (Right y) = ignore (f y)
1309 iterI _ (Left x) = ()
1310 iterI f (Right y) = ignore (f 0 y)
1312 instance Monad (Either b) where
1315 Left x >>= _ = Left x
1318 join (Left x) = Left x
1323 importJava "java.lang.String" where
1326 concatString :: String -> String -> String
1328 @JavaName "compareTo"
1329 compareString :: String -> String -> Integer
1332 lengthString :: String -> Integer
1335 `replaceString original pattern replacement` replaces all occurrences of `pattern` in the string by `replacement`.
1338 replaceString :: String -> String -> String -> String
1342 splitString_ :: String -> String -> Array String
1345 `indexOf string s` finds the first occurrence of `s` from `string` and returns its index.
1346 If the `s` does not occur in the string, return `-1`."
1349 indexOf :: String -> String -> Integer
1351 "Works like `indexOf` but starts searching from the given index instead of the beginning of the string."
1353 indexOfStartingFrom :: String -> String -> Integer -> Integer
1355 "Works like `indexOf` but returns the index of the last occurrence."
1356 @JavaName lastIndexOf
1357 lastIndexOf :: String -> String -> Integer
1359 "Works like `lastIndexOf` but starts searching from the given index instead of the end of the string."
1360 @JavaName lastIndexOf
1361 lastIndexOfStartingFrom :: String -> String -> Integer -> Integer
1365 subString :: String -> Integer -> Integer -> String
1368 `regionMatches str1 offset1 str2 offset2 len` tests whether
1369 `sub str1 offset1 (offset1+len) == sub str2 offset2 (offset2+len)`.
1371 regionMatches :: String -> Integer -> String -> Integer -> Integer -> Boolean
1373 "`startsWith string prefix` returns true if the string begins with the given prefix."
1374 startsWith :: String -> String -> Boolean
1376 "`endsWith string suffix` returns true if the string ends with the given prefix."
1377 endsWith :: String -> String -> Boolean
1379 "Removes leading and trailing whitespace from the string."
1380 trim :: String -> String
1382 "`contains string s` returns true if `string` contains `s` as a substring."
1383 contains :: String -> String -> Boolean
1385 "`charAt string i` returns the `i`th character of the string."
1386 charAt :: String -> Integer -> Character
1388 "Converts all letters of the string to lower case."
1389 toLowerCase :: String -> String
1390 "Converts all letters of the string to upper case."
1391 toUpperCase :: String -> String
1393 "Creates a string from a vector of characters."
1395 string :: Vector Character -> String
1397 instance Ord String where
1398 compare = compareString
1400 instance Additive String where
1403 sum ss = runProc (StringBuilder.toString $ foldl StringBuilder.appendString StringBuilder.new ss)
1406 importJava "org.simantics.scl.runtime.string.StringEscape" where
1407 appendEscapedString :: StringBuilder.T -> String -> <Proc> StringBuilder.T
1409 instance Show String where
1410 showForPrinting = id
1411 sb <+ v = (appendEscapedString (sb << "\"") v) << "\""
1413 instance Read String where
1416 @deprecated "Instead of 'splitString text pattern', write 'split pattern text' (note change in the parameter order)."
1417 "`splitString text pattern` splits the string into a list of string where the parts are sepratated in the original list by the given pattern."
1418 splitString :: String -> String -> [String]
1419 splitString source pattern = arrayToList $ splitString_ source pattern
1422 `split pattern text` splits `text` around matches of the given regular expression `pattern`.
1424 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.
1426 The string "boo:and:foo", for example, yields the following results with these expressions:
1429 : { "boo", "and", "foo" }
1430 o { "b", "", ":and:f" }
1432 split :: String -> String -> [String]
1433 split pattern text = arrayToList $ splitString_ text pattern
1437 instance Ord () where
1440 instance Additive () where
1444 instance Show () where
1449 "Gives the first element of a pair."
1454 "Gives the second element of a pair."
1459 instance (Ord a, Ord b) => Ord (a, b) where
1460 compare (a0, b0) (a1, b1) = compare a0 a1 &<& compare b0 b1
1462 instance (Additive a, Additive b) => Additive (a, b) where
1464 (a0, b0) + (a1, b1) = (a0+a1, b0+b1)
1466 instance Functor ((,) a) where
1467 fmap f (a,b) = (a, f b)
1469 instance (Show a, Show b) => Show (a, b) where
1470 sb <+ (x, y) = sb << "(" <+ x << ", " <+ y << ")"
1474 instance (Ord a, Ord b, Ord c) => Ord (a, b, c) where
1475 compare (a0, b0, c0) (a1, b1, c1) = compare a0 a1 &<& compare b0 b1 &<& compare c0 c1
1477 instance (Additive a, Additive b, Additive c) => Additive (a, b, c) where
1478 zero = (zero, zero, zero)
1479 (a0, b0, c0) + (a1, b1, c1) = (a0+a1, b0+b1, c0+c1)
1481 instance Functor ((,,) a b) where
1482 fmap f (a,b,c) = (a, b, f c)
1484 instance (Show a, Show b, Show c) => Show (a, b, c) where
1485 sb <+ (x, y, z) = sb << "(" <+ x << ", " <+ y << ", " <+ z << ")"
1489 instance (Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d) where
1490 compare (a0, b0, c0, d0) (a1, b1, c1, d1) =
1491 compare a0 a1 &<& compare b0 b1 &<& compare c0 c1 &<& compare d0 d1
1493 instance (Additive a, Additive b, Additive c, Additive d) => Additive (a, b, c, d) where
1494 zero = (zero, zero, zero, zero)
1495 (a0, b0, c0, d0) + (a1, b1, c1, d1) = (a0+a1, b0+b1, c0+c1, d0+d1)
1497 instance Functor ((,,,) a b c) where
1498 fmap f (a,b,c,d) = (a, b, c, f d)
1500 instance (Show a, Show b, Show c, Show d) => Show (a, b, c, d) where
1501 sb <+ (x, y, z, w) = sb << "(" <+ x << ", " <+ y << ", " <+ z << ", " <+ w << ")"
1505 instance (Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e) where
1506 compare (a0, b0, c0, d0, e0) (a1, b1, c1, d1, e1) =
1507 compare a0 a1 &<& compare b0 b1 &<& compare c0 c1 &<& compare d0 d1 &<& compare e0 e1
1509 instance (Additive a, Additive b, Additive c, Additive d, Additive e) => Additive (a, b, c, d, e) where
1510 zero = (zero, zero, zero, zero, zero)
1511 (a0, b0, c0, d0, e0) + (a1, b1, c1, d1, e1) = (a0+a1, b0+b1, c0+c1, d0+d1, e0+e1)
1513 instance Functor ((,,,,) a b c d) where
1514 fmap f (a,b,c,d,e) = (a, b, c, d, f e)
1518 instance (Ord a) => Ord [a] where
1519 compare a b = loop 0
1524 then (if i >= lB then 0 else -1)
1527 else compare (a!i) (b!i) &<& loop (i+1)
1529 instance Functor [] where
1532 instance FunctorE [] where
1537 instance Monad [] where
1538 return x = singletonList x
1539 l >>= f = concatMap f l
1542 instance MonadZero [] where
1545 instance MonadPlus [] where
1548 instance Additive [a] where
1552 instance FunctorM [] where
1553 sequence = foldl (\m mel -> m >>= \l -> mel >>= \el -> return (addList l el)) (return emptyList)
1554 mapM f l = sequence (map f l)
1556 "Appends the string representations of all elements of the list to the string builder and separates the values with the given separator."
1557 printWithSeparator :: Show a => StringBuilder.T -> String -> [a] -> <Proc> StringBuilder.T
1558 printWithSeparator sb sep l = loop 0
1561 loop i = if i >= len then sb
1563 (if i==0 then sb else sb << sep) <+ l!i
1567 Joins the string representations of the list of values with the given separator.
1569 See [intercalate](#intercalate) for an alternative that works with Strings
1570 and doesn't escape its arguments.
1572 joinWithSeparator :: Show a => String -> [a] -> String
1573 joinWithSeparator separator values = runProc (
1574 StringBuilder.toString $ printWithSeparator StringBuilder.new separator values)
1578 The intercalate function takes a String and a list of Strings
1579 and concatenates the list after interspersing the first argument
1580 between each element of the list.
1582 See also more generic [joinWithSeparator](#joinWithSeparator)
1583 which escapes its arguments using `show`.
1585 intercalate :: String -> [String] -> String
1586 intercalate separator strings = do
1593 sb = StringBuilder.new
1595 loop i | i == l = ()
1597 sb << separator << strings!i
1600 StringBuilder.toString sb
1602 instance (Show a) => Show [a] where
1607 if (i>0) then sb << ", " else sb
1614 importJava "java.util.List" where
1615 "`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."
1617 getList :: [a] -> Integer -> a
1621 lengthList :: [a] -> Integer
1624 subList :: [a] -> Integer -> Integer -> [a]
1627 isEmpty :: [a] -> Boolean
1630 importJava "java.util.Collections" where
1632 //singletonList :: a -> [a]
1637 emptyList = build (\empty cons -> empty)
1640 "Creates a list with exectly one element."
1642 singletonList :: a -> [a]
1643 singletonList v = build (\empty cons -> cons empty v)
1646 // foldl f i (a + b) = foldl f (foldl f i a) b
1648 appendList :: [a] -> [a] -> [a]
1649 appendList a b = build (\empty cons -> foldl cons (foldl cons empty a) b)
1652 importJava "org.simantics.scl.runtime.list.ShareableList" where
1653 "Concatenates two lists."
1656 appendList :: [a] -> [a] -> [a]
1658 "Adds the given value to the end of the list."
1660 addList :: [a] -> a -> [a]
1663 importJava "java.util.ArrayList" where
1667 newArrayList :: <Proc> ArrayList a
1670 addArrayList :: ArrayList a -> a -> <Proc> ()
1673 A primitive for constructing a list by `empty` and `cons` operations given to the function given as a parameter to this function.
1676 build (\empty cons -> cons (cons (cons empty 1) 2) 3)
1682 The SCL compiler makes the following optimization when encountering `build` and `foldl` functions after inlining:
1684 foldl f i (build g) = g i f
1687 build :: forall b e2. (forall a e1. a -> (a -> b -> <e1> a) -> <e1,e2> a) -> <e2> [b]
1688 build f = runProc do
1690 f () (\_ v -> addArrayList l v)
1693 "A specific implementation of `map` for lists."
1696 mapEList :: (a -> <e> b) -> [a] -> <e> [b]
1697 mapEList f l = build (\empty cons -> foldl (\cur x -> cons cur (f x)) empty l)
1699 "A specific implementation of `fmap` for lists."
1701 mapList :: (a -> b) -> [a] -> [b]
1702 mapList f l = build (\empty cons -> foldl (\cur x -> cons cur (f x)) empty l)
1704 "`guardList v` returns a singleton `[()]` if `v=True` and the empty list if `v=False`."
1706 guardList :: Boolean -> [()]
1707 guardList cond = build (\empty cons -> if cond then cons empty () else empty)
1710 `concatMap` combines `map` and `join` functions.
1711 It maps the elements of a given list to lists with the given function and concatenates the results.
1713 concatMap f lst = join (map f lst) = [y | x <- lst, y <- f x]
1716 concatMap :: (a -> <e> [b]) -> [a] -> <e> [b]
1717 concatMap f l = build (\empty cons -> foldl (\cur le -> foldl cons cur (f le)) empty l)
1720 Applies the given function to the elements of the lists until the function returns something
1721 else than `Nothing`. This return value is also returned as a result of this function.
1724 mapFirst :: (a -> <e> Maybe b) -> [a] -> <e> Maybe b
1725 mapFirst f l = loop 0
1728 loop i = if i == len
1730 else match f (l!i) with
1732 Nothing -> loop (i+1)
1735 foldl op initialValue list
1737 applies a binary operator `op` to all elements of `list` from left to right
1738 starting with `initialValue`. For example,
1740 foldl op init [x1, x2, x3, x4] = (((init `op` x1) `op` x2) `op` x3) `op` x4
1743 foldl :: forall a b e. (a -> b -> <e> a) -> a -> [b] -> <e> a
1744 foldl f initial l = loop initial 0
1747 loop cur i = if i==len
1749 else loop (f cur (l!i)) (i+1)
1751 foldlI :: forall a b e. (Integer -> a -> b -> <e> a) -> a -> [b] -> <e> a
1752 foldlI f initial l = loop initial 0
1755 loop cur i = if i==len
1757 else loop (f i cur (l!i)) (i+1)
1759 scanl :: (b -> a -> <e> b) -> b -> [a] -> <e> [b]
1760 scanl f initial l = build (\empty cons -> let
1762 loop cur i accum = let nl = cons accum cur
1765 else loop (f cur (l!i)) (i+1) nl
1766 in loop initial 0 empty)
1768 "`foldr` is defined like `foldl` but it process the list from right to left."
1770 foldr :: (b -> a -> <e> a) -> a -> [b] -> <e> a
1771 foldr f initial l = loop initial (length l - 1)
1773 loop cur i = if i < 0
1775 else loop (f (l!i) cur) (i-1)
1777 foldr1 :: (a -> a -> <e> a) -> [a] -> <e> a
1778 foldr1 f l = loop (l!(len-1)) (len-2)
1781 loop cur i = if i < 0
1783 else loop (f (l!i) cur) (i-1)
1786 `filter pred lst` returns those elements of `lst` that the predicate `pred` accepts. For example
1788 filter (> 3) [1, 2, 3, 4, 5, 6] = [4, 5, 6]
1791 filter :: (a -> <e> Boolean) -> [a] -> <e> [a]
1792 filter p l = build (\empty cons -> foldl (\cur x -> if p x then cons cur x else cur) empty l)
1795 Takes those elements of the input list that match `(Just x)` and adds the contents to the resulting list. For example,
1797 filterJust [Just 1, Nothing, Just 5] = [1, 5]
1800 filterJust :: [Maybe a] -> [a]
1801 filterJust l = build (\empty cons -> foldl (\cur x -> match x with Just v -> cons cur v ; _ -> cur) empty l)
1803 listToMaybe :: [a] -> Maybe a
1804 listToMaybe l = if isEmpty l then Nothing else Just (l!0)
1806 maybeToList :: Maybe a -> [a]
1807 maybeToList (Just a) = [a]
1811 `takeWhile p l`, returns the longest prefix (possibly empty) of list `l` of elements that satisfy `p`
1813 takeWhile :: (a -> <e> Boolean) -> [a] -> <e> [a]
1814 takeWhile f l = loop 0
1817 loop i | i == len = l
1818 | f (l!i) = loop (i+1)
1819 | otherwise = take i l
1821 partition :: (a -> <e> Boolean) -> [a] -> <e> ([a], [a])
1822 partition p l = runProc do
1827 then addArrayList res1 el
1828 else addArrayList res2 el
1830 (Java.unsafeCoerce res1, Java.unsafeCoerce res2)
1833 `range begin end` produces a list of consecutive integers starting from `begin` and ending to `end` (including `end`).
1834 The compiler supports syntactic sugar `[begin..end]` for this function.
1837 range :: Integer -> Integer -> [Integer]
1838 range first last = build (\empty cons -> do
1839 loop i cur = if i > last then cur else loop (i+1) (cons cur i)
1842 "A specific implementation of `iter` for lists."
1844 iterList :: (a -> <e> b) -> [a] -> <e> ()
1845 iterList f l = foldl (\_ x -> ignore (f x)) () l
1847 "A specific implementation of `iterI` for lists."
1849 iterIList :: (Integer -> a -> <e> b) -> [a] -> <e> ()
1850 iterIList f l = do foldl (\i x -> do f i x ; i+1) 0 l ; ()
1853 Generates a list from a given starting state and iteration function.
1856 let nextState 0 = Nothing
1857 nextState i = Just (i, i `div` 2)
1858 in unfoldr nextState 30
1865 unfoldr :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1866 unfoldr f s = build (\empty cons -> do
1869 Just (el,newS) -> loop newS (cons cur el)
1873 importJava "org.simantics.scl.runtime.Lists" where
1877 mapList :: (a -> b) -> [a] -> [b]
1880 mapEList :: (a -> <e> b) -> [a] -> <e> [b]
1883 iterList :: (a -> <e> ()) -> [a] -> <e> ()
1884 concatMap :: (a -> <e> [b]) -> [a] -> <e> [b]
1887 Combines two lists into one list of pairs. The length of the resulting list is the length of the smallest input list.
1889 zip [1, 2, 3, 4, 5] ['a', 'b', 'c'] = [(1, 'a'), (2, 'b'), (3, 'c')]
1891 zip :: [a] -> [b] -> [(a,b)]
1892 "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."
1893 zipWith :: (a -> b -> <e> c) -> [a] -> [b] -> <e> [c]
1895 Produces two lists from one list of pairs.
1897 unzip [(1, 'a'), (2, 'b'), (3, 'c')] = ([1, 2, 3], ['a', 'b', 'c'])
1899 unzip :: [(a,b)] -> ([a],[b])
1901 //"@filter p l@ returns those elements of @l@ that the predicate @p@ accepts."
1902 //filter :: (a -> <e> Boolean) -> [a] -> <e> [a]
1903 //filterJust :: [Maybe a] -> [a]
1905 foldl :: (a -> b -> <e> a) -> a -> [b] -> <e> a
1907 "Like `foldl` but assumes that the list is non-empty so the initial is not needed."
1908 foldl1 :: (a -> a -> <e> a) -> [a] -> <e> a
1909 //unfoldr :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1911 "Sorts the list using the given comparator."
1912 sortWith :: (a -> a -> <e> Integer) -> [a] -> <e> [a]
1913 "Works like `index` but uses the given functions as hash codes and equality."
1914 indexWith :: (a -> Integer) -> (a -> a -> Boolean) -> [(a,b)] -> a -> Maybe b
1915 groupWith :: (b -> Integer) -> (b -> b -> Boolean) -> (a -> <e> b) -> (a -> <e> c) -> [a] -> <e> [(b, [c])]
1916 "Works like `unique` but uses the given function for equality tests."
1917 uniqueWith :: (a -> a -> Boolean) -> [a] -> [a]
1918 "Works like `\\\\` but uses the given function for equality tests."
1919 deleteAllBy :: (a -> a -> Boolean) -> [a] -> [a] -> [a]
1921 //range :: Integer -> Integer -> [Integer]
1923 //build :: (forall a. a -> (a -> b -> <e> a) -> <e> a) -> <e> [b]
1925 "`elem el lst` return true, if `el` occurs in the list `lst`."
1926 elem :: a -> [a] -> Boolean
1930 loop i | i < len = if el == l!i
1935 "`elemMaybe v1 (Just v2)` returns true if `v1 == v2`. `elemMaybe v1 Nothing` is always false."
1936 elemMaybe :: a -> Maybe a -> Boolean
1937 elemMaybe el m = match m with
1938 Just el2 -> el == el2
1942 Computes a list that contains only elements that belongs to both input lists.
1944 intersect :: [a] -> [a] -> [a]
1945 intersect a b = filter f a
1949 "Reverses a given list. For example, `reverse [1,2,3] = [3,2,1]`"
1950 reverse :: [a] -> [a]
1951 reverse l = [l!(len-i) | i <- [1..len]]
1956 Transposes the rows and columns of its argument. For example,
1958 transpose [[1,2,3],[4,5,6]] == [[1,4],[2,5],[3,6]]
1959 transpose [[1,2],[3,4,5]] == [[1,3],[2,4],[5]]
1961 transpose xss = [[xs!i | xs <- xss, i < length xs]
1962 | i <- [0..maximum [length xs | xs <- xss]-1]]
1964 "Works like `unfoldr` but generates the list from right to left."
1965 unfoldl :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1966 unfoldl f seed = reverse $ unfoldr f seed
1968 "Removes the first element of the list, if the list is non-empty."
1970 tail l = if len < 2 then emptyList else subList l 1 len
1974 "Tries to find the given key from the list of key-value pairs and returns the corresponding value."
1975 lookup :: a -> [(a, b)] -> Maybe b
1980 (a,b) | a == el -> Just b
1981 | otherwise -> loop (i+1)
1985 "Conjunction over a list."
1987 and :: [Boolean] -> Boolean
1988 and = foldl (&&) True
1990 "Disjunction over a list."
1992 or :: [Boolean] -> Boolean
1993 or = foldl (||) False
1996 `any pred lst` tests whether the predicate `pred` holds some element of `lst`.
1997 It returns immediately when it encounters the first value satisfying the predicate.
1999 any :: (a -> <e> Boolean) -> [a] -> <e> Boolean
2003 `all pred lst` tests whether the predicate `pred` holds for all elements of `lst`.
2004 It returns immediately when it encounters the first value not satisfying the predicate.
2006 all :: (a -> <e> Boolean) -> [a] -> <e> Boolean
2010 Returns the first element of the list satisfying the given condition,
2011 or `Nothing` if there is no such element.
2013 findFirst :: (a -> <e> Boolean) -> [a] -> <e> Maybe a
2014 findFirst p l = loop 0
2018 then let el = l!i in
2027 Sorts the given list using its default order.
2030 sort :: Ord a => [a] -> [a]
2031 sort = sortWith compare
2034 Sorts the lists by the values computed by the first function.
2037 sortBy snd [(1,5), (2,3), (3,4)] = [(2,3), (3,4), (1,5)]
2040 sortBy :: Ord b => (a -> <e> b) -> [a] -> <e> [a]
2041 sortBy f l = sortWith (\x y -> compare (f x) (f y)) l
2042 // This is faster if f is slow, but will generate more auxiliary structures
2043 //sortBy f l = map snd (sortWith (\(x,_) (y,_) -> compare x y) [(f x, x) | x <- l])
2046 Given a list of key-value pairs, the function produces a function that finds a value
2047 efficiently for the given key.
2049 index :: [(a,b)] -> a -> Maybe b
2050 index = indexWith hashCode (==)
2053 Given a list of values and a function computing a key for each value, the function produces a function that finds a value
2054 effeciently for the given key.
2056 indexBy :: (a -> b) -> [a] -> b -> Maybe a
2057 indexBy f l = index [(f x, x) | x <- l]
2059 "Groups a list values by a key computed by the given function."
2060 groupBy :: (a -> <e> b) -> [a] -> <e> [(b, [a])]
2061 groupBy f l = groupWith hashCode (==) f id l
2063 "Groups a list of key-value pairs by the keys."
2064 group :: [(a,b)] -> [(a, [b])]
2065 group = groupWith hashCode (==) fst snd
2067 "Removes duplicates (all but the first occurrence) from the list but otherwise preserves the order of the elements."
2068 unique :: [a] -> [a]
2069 unique = uniqueWith (==)
2071 "Like `unique`, but uses the given function for finding the key values used for uniqueness testing."
2072 uniqueBy :: (a -> b) -> [a] -> [a]
2073 uniqueBy f = uniqueWith (\a b -> f a == f b)
2075 //sortAndUniqueBy :: Ord b => (a -> b) -> [a] -> [a]
2076 //sortAndUniqueBy f = map snd . uniqueWith (\a b -> fst a == fst b) . sortBy fst . map (\x -> (f x, x))
2078 "`a \\\\ b` removes all elements of `b` from the list `a`."
2079 (\\) :: [a] -> [a] -> [a]
2080 (\\) = deleteAllBy (==)
2084 importJava "java.lang.Object" where
2085 "A data type that can represent any value."
2090 showDynamic :: Dynamic -> String
2092 instance Show Dynamic where
2095 "Converts a value to `Dynamic` type."
2096 toDynamic :: a -> Dynamic
2097 toDynamic = Java.unsafeCoerce
2099 "Converts a `Dynamic` value to a required value, or fails if the conversion is not possible."
2100 importJava "org.simantics.scl.compiler.runtime.ValueConversion" where
2101 fromDynamic :: Typeable a => Dynamic -> a
2105 importJava "org.simantics.scl.runtime.procedure.Ref" where
2106 "A mutable reference to a value of type `a`."
2109 "Creates a new reference with the given initial value."
2111 ref :: a -> <Proc> (Ref a)
2113 "Returns the current value of the reference."
2115 getRef :: Ref a -> <Proc> a
2117 "Sets a new value for the reference."
2118 @JavaName "<set>value"
2119 (:=) :: Ref a -> a -> <Proc> ()
2121 instance Show (Ref a) where
2122 show _ = "<reference>"
2124 importJava "org.simantics.scl.runtime.reporting.SCLReporting" where
2125 "Prints the given string to the console."
2127 printString :: String -> <Proc> ()
2128 "Prints an error message to the console."
2129 printError :: String -> <Proc> ()
2130 "Reports that certain amount of work has been done for the current task."
2131 didWork :: Double -> <Proc> ()
2133 `printingToFile "fileName" expression` executes the `expression` so that all its console prints
2134 are written to the file given as a first parameter.
2136 printingToFile :: String -> (<e> a) -> <e> a
2138 `printErrorsAsNormalPrints expression` executes the `expression` so that all its error prints
2139 are printed as normal prints. This is useful mainly in testing scripts for checking that the implementations
2140 give proper error messages with invalid inputs.
2142 printErrorsAsNormalPrints :: (<e> a) -> <e> a
2144 `disablePrintingForCommand expression` executes the `expression` so that it does not print return values.
2145 Errors are printed normally.
2147 disablePrintingForCommand :: (<e> a) -> <e> a
2150 importJava "org.simantics.scl.runtime.procedure.Procedures" where
2151 "Returns `True` if the current thread has been interrupted."
2152 isInterrupted :: <Proc> Boolean
2153 "Checks whether the current thread has been interrupted and throws an exception if it is."
2154 checkInterrupted :: <Proc> ()
2155 "Generates a random identifier."
2156 generateUID :: <Proc> String
2158 "Executes the given expression and catches certain class of exceptions (specified by the catch handler that is given as a second parameter.)"
2160 catch :: VecComp ex => (<e,Exception> a) -> (ex -> <e> a) -> <e> a
2162 importJava "java.lang.Throwable" where
2166 showThrowable :: Throwable -> String
2167 importJava "java.lang.Exception" where
2171 showException :: Exception -> String
2173 instance Show Throwable where
2174 show = showThrowable
2175 instance Show Exception where
2176 show = showException
2178 "Prints the given value in the console."
2180 print :: Show a => a -> <Proc> ()
2181 print v = printString (showForPrinting v)
2183 instance Show TypeRep where
2184 sb <+ (TApply (TCon "Builtin" "[]") b) =
2185 sb << "[" <+ b << "]"
2186 sb <+ (TApply (TApply (TCon "Builtin" "(,)") c1) c2) =
2187 sb << "(" <+ c1 << "," <+ c2 << ")"
2188 sb <+ (TApply (TApply (TApply (TCon "Builtin" "(,,)") c1) c2) c3) =
2189 sb << "(" <+ c1 << "," <+ c2 << "," <+ c3 << ")"
2190 sb <+ (TApply (TApply (TApply (TApply (TCon "Builtin" "(,,,)") c1) c2) c3) c4) =
2191 sb << "(" <+ c1 << "," <+ c2 << "," <+ c3 << "," <+ c4 << ")"
2193 sb <+ (TCon _ name) = sb << name
2194 sb <+ (TApply a b) = sb <+ Par 1 a << " " <+ Par 2 b
2195 sb <+ (TFun a b) = sb <+ Par 1 a << " -> " <+ b
2197 precedence (TCon _ _) = 0
2198 precedence (TFun _ _) = 2
2199 precedence (TApply a _) = if isSpecialType a then 0 else 1
2201 isSpecialType (TCon "Builtin" "[]") = True
2202 isSpecialType (TCon "Builtin" "()") = True
2203 isSpecialType (TCon "Builtin" "(,)") = True
2204 isSpecialType (TCon "Builtin" "(,,)") = True
2205 isSpecialType (TCon "Builtin" "(,,,)") = True
2206 isSpecialType (TApply a _) = isSpecialType a
2211 importJava "java.util.Arrays" where
2214 byteArrayToString :: ByteArray -> String
2216 instance Show ByteArray where
2217 show = byteArrayToString
2222 importJava "org.simantics.scl.compiler.types.Type" where
2224 showType :: Type -> String
2226 importJava "org.simantics.scl.compiler.types.Types" where
2227 removeForAll :: Type -> Type
2229 instance Show Type where