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 type BooleanArray = Vector Boolean
42 type ByteArray = Vector Byte
43 type CharacterArray = Vector Character
44 type ShortArray = Vector Short
45 type IntegerArray = Vector Integer
46 type LongArray = Vector Long
47 type FloatArray = Vector Float
48 type DoubleArray = Vector Double
50 importJava "java.util.Arrays" where
51 "Converts an array to a list."
53 arrayToList :: Array a -> [a]
55 importJava "java.util.List" where
56 "Converts a list to an array."
58 listToArray :: [a] -> Array a
60 importJava "org.simantics.scl.runtime.Coercion" where
61 "Converts a list of doubles to a double array."
62 toDoubleArray :: [Double] -> DoubleArray
63 "Converts a double array to a list of doubles."
64 fromDoubleArray :: DoubleArray -> [Double]
67 * Precedences and associativity of all operators defined in Prelude
73 infixl 7 (*), (/), div, mod
75 infixl 5 (\\), (<<), (<+)
76 infix 4 (!=), (<), (<=), (>=), (>)
78 infixr 2 (||), orElse, morelse
79 infixr 1 (>>=), (>>), (:=), (>=>)
83 "Creates a constant function. `const x` defines a function that always returns `x`."
89 Function application. `f $ x` is equivalent with `f x`. The function has two uses.
90 First is to remove parentheses from deeply nested expressions:
92 f (g (h x)) == f $ g $ h x
94 The second use is with higher order functions:
96 map ($ parameter) functions
100 ($) :: (a -> <e> b) -> a -> <e> b
103 "Transforms a function taking a pair as a parameter to a function taking two values as a parameter."
105 curry :: ((a, b) -> <e> c) -> a -> b -> <e> c
106 curry f x y = f (x, y)
108 "Transforms a function two values as a parameter to a function taking a pair as a parameter."
110 uncurry :: (a -> b -> <e> c) -> ((a, b) -> <e> c)
111 uncurry f (x, y) = f x y
113 "Transforms a function taking a triple as a parameter to a function taking three values as a parameter."
115 curry3 :: ((a, b, c) -> <e> d) -> a -> b -> c -> <e> d
116 curry3 f x y z = f (x, y, z)
118 "Transforms a function three values as a parameter to a function taking a priple as a parameter."
120 uncurry3 :: (a -> b -> c -> <e> d) -> ((a, b, c) -> <e> d)
121 uncurry3 f (x, y, z) = f x y z
123 "Flips the parameters of a binary function."
125 flip :: (a -> b -> <e> c) -> b -> a -> <e> c
128 "Swaps the order of elements of a pair (2-tuple)."
129 swap :: (a,b) -> (b,a)
135 (!=) :: a -> a -> Boolean
136 a != b = not (a == b)
139 The class of linearly ordered types.
140 Method `compare` must be implemented in instances.
144 `compare x y` returns a negative number, if `x` is smaller than `y`,
145 a positive number, if `x` is bigger than `y` and zero if they are equal.
147 compare :: a -> a -> Integer
148 compare a b = if a < b then -1 else if a > b then 1 else 0
151 (<) :: a -> a -> Boolean
152 a < b = compare a b < 0
154 (<=) :: a -> a -> Boolean
155 a <= b = compare a b <= 0
157 (>) :: a -> a -> Boolean
158 a > b = compare a b > 0
160 (>=) :: a -> a -> Boolean
161 a >= b = compare a b >= 0
163 "Minimum of the parameters"
165 min a b = if a < b then a else b
166 "Maximum of the parameters"
168 max a b = if a > b then a else b
171 Combines two integers such that if the first one is non-zero, it is returned, otherwise
172 the second-one. The second parameter is not implemented, if it is not needed.
174 The function is useful for implementing efficient recursive comparison of structures,
177 compare (x1,y1,z1) (x2,y2,z2) = compare x1 x2 &<& compare y1 y2 &<& compare z1 z2
180 (&<&) :: Integer -> (<e> Integer) -> <e> Integer
181 a &<& b = if a == 0 then b else a
183 "Maximum over a list"
185 maximum :: Ord a => [a] -> a
188 "Minimum over a list"
190 minimum :: Ord a => [a] -> a
193 "As `maximum` but compares the elements by the given projection."
194 maximumBy :: Ord b => (a -> <e> b) -> [a] -> <e> a
195 maximumBy f l = snd $ foldl1 maxF $ map (\x -> (f x, x)) l
197 maxF a b = if fst a >= fst b then a else b
200 As `minimum` but compares the elements by the given projection.
205 returns a pair with the smallest second component.
207 minimumBy :: Ord b => (a -> <e> b) -> [a] -> <e> a
208 minimumBy f l = snd $ foldl1 minF $ map (\x -> (f x, x)) l
210 minF a b = if fst a <= fst b then a else b
214 instance Functor ((->) a) where
217 instance Monad ((->) a) where
219 (m >>= f) x = f (m x) x
222 instance Category (->) where
227 instance (Additive b) => Additive (a -> <e> b) where
229 (f + g) x = f x + g x
231 instance (Ring b) => Ring (a -> <e> b) where
233 (neg f) x = neg (f x)
234 (f - g) x = f x - g x
235 (f * g) x = f x * g x
236 (fromInteger c) x = fromInteger c
238 //instance Show (a -> <e> b) where
239 // show f = "<function>"
241 "Appends a string to the string builder."
242 (<<) :: StringBuilder.T -> String -> <Proc> StringBuilder.T
243 (<<) = StringBuilder.appendString
246 The class of types whose elements can be converted to a string representation.
247 Method `show` or `(<+)` must be implemented.
250 "Converts a value to string."
252 "Appends the string representation of the value to the string builder."
253 (<+) :: StringBuilder.T -> a -> <Proc> StringBuilder.T
255 Returns the precedence of the value. It is used to determine if parenteheses
256 are needed around the string representation of the value. The default value is 0
257 and means that parentheses are never added.
259 precedence :: a -> Integer
261 "Converts a value to a string like `show` but does not put string literals in double quotes."
262 showForPrinting :: a -> String
264 show v = runProc (StringBuilder.toString (StringBuilder.new <+ v))
265 showForPrinting v = show v
266 sb <+ v = StringBuilder.appendString sb (show v)
270 `Par` data type is used to control the placement of parentheses when converting values to string.
271 Value `Par prec val` is converted to string like `val` but parentheses are put around, if the
272 precedence of the value is greater than `prec`.
274 data Par a = Par Integer a
276 instance (Show a) => Show (Par a) where
277 sb <+ (Par outerPrec v) = if prec > outerPrec
278 then sb << "(" <+ v << ")"
280 where prec = precedence v
282 "Type class for parsing strings to values."
284 "Converts a string to a required type of value."
287 The `Additive` class is used for types that are additive monoids. The operations
288 must satisfy the following laws (at least approximately, when implemented for
289 floating point numbers):
290 (a + b) + c = a + (b + c)
293 class Additive a where
295 Neutral element of (+), i.e,
301 "Adds two objects (numbers, vectors, strings, etc.) together."
306 sum [e1,e2,...,eN] = e1 + e2 + ... + eN
308 Implemented usually more efficiently than with repetitive
309 application of `(+)`.
314 class (Additive a) => AdditiveGroup a where
320 The `Ring` class is used for types that are algebraic rings. The operations
321 must satisfy the following laws (at least approximately)
322 in addition to the laws of Additive:
327 (a * b) * c = a * (b * c)
329 a * (b + c) = a * b + a * c
330 (a + b) * c = a * c + b * c
332 class (Additive a) => Ring a where
334 Negation. Synonym for unary `-`.
339 "Neutral element of multiplication"
343 "Converts an integer to a desired numeric type."
344 fromInteger :: Integer -> a
349 The `OrderedRing` class combines the Ring and Ord classes. It additionally
350 supports absolute value function.
352 class (Ring a, Ord a) => OrderedRing a where
355 abs x = if x < zero then neg x else x
356 "Converts the given number to `Integer`"
357 toInteger :: a -> Integer
360 The `Integer` class is used for types that represent either all integers or some
363 class (OrderedRing a) => Integral a where
364 "Integer division truncated toward zero."
366 "Integer remainder, satisfying ``(x `div` y)*y + (x `mod` y) = x``"
370 The `Real` class is used for types that represent some approximation of real numbers.
372 class (OrderedRing a) => Real a where
377 "Pi (3.141592654...)"
403 "Inverse hyberbolic sine"
405 "Inverse hyberbolic cosine"
407 "Inverse hyberbolic tangent"
409 "The largest integer not greater than the given number"
411 "The smallest integer not smaller than the given number"
415 Two parameter version of `atan`. Its value is determined by the following
416 equations when (x,y) is a unit vector:
423 atan2 y x = atan (y/x)
426 "Converts a `Double` value to a desired numeric type."
427 fromDouble :: Double -> a
428 "Converts the given number to `Double`"
429 toDouble :: a -> Double
431 a ^ b = exp (b * log a)
433 sinh x = 0.5 * (exp x - exp (neg x))
434 cosh x = 0.5 * (exp x + exp (neg x))
435 tanh x = (e2x - 1) / (e2x + 1)
439 asinh x = log (x + sqrt (x*x + one))
440 acosh x = log (x + sqrt (x*x - one))
441 atanh x = 0.5 * log ((one+x)/(one-x))
443 /// Import mathematical functions ///
446 importJava "java.lang.Math" where
451 sinDouble :: Double -> Double
454 cosDouble :: Double -> Double
457 tanDouble :: Double -> Double
460 asinDouble :: Double -> Double
463 acosDouble :: Double -> Double
466 atanDouble :: Double -> Double
469 atan2Double :: Double -> Double -> Double
472 sinhDouble :: Double -> Double
475 coshDouble :: Double -> Double
478 tanhDouble :: Double -> Double
481 expDouble :: Double -> Double
484 logDouble :: Double -> Double
487 powDouble :: Double -> Double -> Double
490 sqrtDouble :: Double -> Double
493 ceilDouble :: Double -> Double
496 floorDouble :: Double -> Double
499 roundDouble :: Double -> Long
502 absInteger :: Integer -> Integer
505 absLong :: Long -> Long
508 absFloat :: Float -> Float
511 absDouble :: Double -> Double
514 minInteger :: Integer -> Integer -> Integer
517 minLong :: Long -> Long -> Long
520 minFloat :: Float -> Float -> Float
523 minDouble :: Double -> Double -> Double
526 maxInteger :: Integer -> Integer -> Integer
529 maxLong :: Long -> Long -> Long
532 maxFloat :: Float -> Float -> Float
535 maxDouble :: Double -> Double -> Double
540 importJava "java.lang.Byte" where
542 showByte :: Byte -> String
545 readByte :: String -> Byte
547 instance Ord Byte where
553 instance Additive Byte where
554 zero = Java.i2b Java.iconst_0
557 instance Ring Byte where
560 one = Java.i2b Java.iconst_1
562 fromInteger = Java.i2b
564 instance Show Byte where
566 precedence v = if v >= 0 then 0 else 100
568 instance Read Byte where
573 importJava "java.lang.Short" where
575 showShort :: Short -> String
578 readShort :: String -> Short
580 instance Ord Short where
586 instance Additive Short where
590 instance Ring Short where
595 fromInteger = Java.i2s
597 instance Show Short where
599 precedence v = if v >= 0 then 0 else 100
601 instance Read Short where
607 importJava "java.lang.Integer" where
609 showInteger :: Integer -> String
612 readInteger :: String -> Integer
614 instance Ord Integer where
620 instance Additive Integer where
624 instance Ring Integer where
631 instance OrderedRing Integer where
635 instance Integral Integer where
639 instance Show Integer where
641 precedence v = if v >= 0 then 0 else 100
643 instance Read Integer where
649 importJava "java.lang.Long" where
651 showLong :: Long -> String
654 readLong :: String -> Long
656 instance Ord Long where
662 instance Additive Long where
666 instance Ring Long where
671 fromInteger = Java.i2l
673 instance OrderedRing Long where
677 instance Integral Long where
681 instance Show Long where
683 precedence v = if v >= 0 then 0 else 100
685 instance Read Long where
690 importJava "java.lang.Float" where
693 compareFloat :: Float -> Float -> Integer
697 showFloat :: Float -> String
701 readFloat :: String -> Float
703 "Converts 32-bit floating point number to a 32-bit integer with the same byte level representation."
704 floatToIntBits :: Float -> Integer
706 instance Ord Float where
707 compare = compareFloat
713 instance Additive Float where
717 instance Ring Float where
722 fromInteger = Java.i2f
724 instance OrderedRing Float where
728 instance Real Float where
730 x ^ y = Java.d2f (powDouble (Java.f2d x) (Java.f2d y))
731 pi = fromDouble piDouble
732 sqrt = Java.d2f . sqrtDouble . Java.f2d
733 exp = Java.d2f . expDouble . Java.f2d
734 log = Java.d2f . logDouble . Java.f2d
735 sin = Java.d2f . sinDouble . Java.f2d
736 cos = Java.d2f . cosDouble . Java.f2d
737 tan = Java.d2f . tanDouble . Java.f2d
738 asin = Java.d2f . asinDouble . Java.f2d
739 acos = Java.d2f . acosDouble . Java.f2d
740 atan = Java.d2f . atanDouble . Java.f2d
741 sinh = Java.d2f . sinhDouble . Java.f2d
742 cosh = Java.d2f . coshDouble . Java.f2d
743 tanh = Java.d2f . tanhDouble . Java.f2d
744 floor = Java.d2f . floorDouble . Java.f2d
745 ceil = Java.d2f . ceilDouble . Java.f2d
746 atan2 y x = Java.d2f (atan2Double (Java.f2d y) (Java.f2d x))
747 round = roundDouble . Java.f2d
748 fromDouble = Java.d2f
751 instance Show Float where
753 precedence v = if v >= 0 then 0 else 100
755 instance Read Float where
760 importJava "java.lang.Double" where
763 compareDouble :: Double -> Double -> Integer
767 showDouble :: Double -> String
770 @JavaName parseDouble
771 readDouble :: String -> Double
773 "Converts 64-bit floating point number to a 64-bit integer with the same byte level representation."
774 doubleToLongBits :: Double -> Long
776 isFinite :: Double -> Boolean
777 isNaN :: Double -> Boolean
778 isInfinite :: Double -> Boolean
780 instance Ord Double where
781 compare = compareDouble
787 instance Additive Double where
791 instance Ring Double where
796 fromInteger = Java.i2d
798 instance OrderedRing Double where
802 instance Real Double where
825 instance Show Double where
827 precedence v = if v >= 0 then 0 else 100
829 instance Read Double where
834 importJava "java.lang.Character" where
836 showCharacter :: Character -> String
838 "Returns true, if the given character is a letter."
839 isLetter :: Character -> Boolean
841 "Returns true, if the given character is a digit."
842 isDigit :: Character -> Boolean
844 instance Ord Character where
850 instance Show Character where
851 sb <+ c = sb << "'" << showCharacter c << "'"
853 "Adds a given integer to the character code."
854 addChar :: Character -> Integer -> Character
857 "Subtracts a given integer from the character code."
858 subChar :: Character -> Character -> Integer
864 The `Functor` class is used for types that can be mapped over. Instances of `Functor` should satisfy the following laws:
867 fmap (f . g) == fmap f . fmap g
869 class Functor f where
870 "Lifts a pure function to the given functor."
871 fmap :: (a -> b) -> f a -> f b
873 class CoFunctor f where
874 comap :: (a -> b) -> f b -> f a
878 class (Functor f) => Applicative f where
880 (<*>) :: f (a -> b) -> f a -> f b
881 (*>) :: f a -> f b -> f b
882 (<*) :: f a -> f b -> f a
884 u *> v = pure (const id) <*> u <*> v
885 u <* v = pure const <*> u <*> v
886 fmap f x = pure f <*> x
891 The `Monad` class defines the basic operations over a monad, a concept from a branch of mathematics known as category theory.
892 From the perspective of a SCL programmer, however, it is best to think of a monad as an abstract datatype of actions.
893 SCL's `mdo expressions provide a convenient syntax for writing monadic expressions.
895 Instances of `Monad` should satisfy the following laws:
897 return a >>= k == k a
899 m >>= (\x -> k x >>= h) == (m >>= k) >>= h
900 fmap f xs == xs >>= return . f
902 class (Functor m) => Monad m where
903 "Inject a value into the monadic type."
905 "Sequentially compose two actions, passing any value produced by the first as an argument to the second."
906 (>>=) :: m a -> (a -> m b) -> m b
908 The join function is the conventional monad join operator. It removes one level of monadic
911 For lists, `join` concatenates a list of lists:
913 join [[1,2], [3,4]] = [1, 2, 3, 4]
915 join :: m (m a) -> m a
919 Sequentially compose two actions, discarding any value produced by the first, like sequencing operators
920 (such as the semicolon) in imperative languages."
923 (>>) :: Monad m => m a -> m b -> m b
924 a >> b = a >>= (\_ -> b)
926 "Left-to-right Kleisli composition of monads."
927 (>=>) :: Monad m => (a -> m b) -> (b -> m c) -> (a -> m c)
928 (f >=> g) x = (f x) >>= g
930 "While loop. `while cond body` executes the `body` while the `cond` is true."
932 while :: (<e> Boolean) -> (<e> a) -> <e> ()
933 while cond body = loop ()
934 where loop _ = if cond
935 then do body ; loop ()
939 Sequences the given monadic value infinitely:
941 repeatForever m = m >> m >> m >> ...
943 repeatForever m = m >> repeatForever m
945 replicateM :: Monad m => Integer -> m a -> m [a]
946 replicateM count m = loop count emptyList
948 loop count l | count <= 0 = return l
951 loop (count-1) (addList l v)
953 replicateM_ :: Monad m => Integer -> m a -> m ()
954 replicateM_ count m | count <= 0 = return ()
955 | otherwise = m >> replicateM_ (count-1) m
960 A class of monads with zero element satisfying
964 class (Monad m) => MonadZero m where
967 "Injects a boolean test to a type beloning to `MonadZero`."
968 guard :: MonadZero m => Boolean -> m ()
969 guard True = return ()
975 A class of monads with associative binary operator `mplus` satisfying the following laws:
979 mplus (mplus a b) c = mplus a (mplus b c)
980 mplus a b >>= k = mplus (a >>= k) (b >>= k)
982 class (MonadZero m) => MonadPlus m where
983 mplus :: m a -> m a -> m a
988 A class of monads with associative binary operator `morelse` satisfying the following laws:
992 morelse (morelse a b) c = morelse a (morelse b c)
993 morelse (return a) b = return a
995 class (MonadZero m) => MonadOr m where
996 morelse :: m a -> m a -> m a
1001 A class of types that can be mapped over with effectful mapping functions.
1003 class (Functor f) => FunctorE f where
1005 Applies the function to all elements of the container and
1006 returns the similarly shaped container with the results:
1010 map f [e1, e2, ..., eN] = [f e1, f e2, ..., f eN]
1014 map (*2) [1..5] = [2, 4, 6, 8, 10]
1016 map :: (a -> <e> b) -> f a -> <e> (f b)
1017 "Calls the given function with all elements of the given container."
1018 iter :: (a -> <e> b) -> f a -> <e> ()
1019 "Calls the given function with all elements of the given container giving also the index of the element as a parameter."
1020 iterI :: (Integer -> a -> <e> b) -> f a -> <e> ()
1022 "Iterates the elements of the given collection. Same as `iter` but parameters flipped."
1023 for :: FunctorE f => f a -> (a -> <e> b) -> <e> ()
1027 "Iterates the elements of the given collection providing also the indices of the elements. Same as `iterI` but parameters flipped."
1028 forI :: FunctorE f => f a -> (Integer -> a -> <e> b) -> <e> ()
1030 forI l f = iterI f l
1032 "`forN n f` calls `f` for all integers `0`, ..., `n-1`"
1034 forN :: Integer -> (Integer -> <e> b) -> <e> ()
1038 then do f i ; loop (i+1)
1042 mapI :: (Integer -> a -> <e> b) -> [a] -> <e> [b]
1043 mapI f l = build (\empty cons -> let
1045 loop i accum = if i < len
1046 then loop (i+1) (cons accum (f i (l!i)))
1051 `mapMaybe` combines `map` and `filter` functions.
1052 It applies the given function to every element of the input list. If the result
1053 is `Just x`, then `x` is added to the resulting list.
1055 mapMaybe f lst = [y | x <- lst, Just y = f x]
1058 mapMaybe :: (a -> <e> Maybe b) -> [a] -> <e> [b]
1059 mapMaybe f l = build (\empty cons -> foldl (\cur x -> match f x with Just v -> cons cur v ; _ -> cur) empty l)
1062 Applies the given function to all elements of the list. Produces two lists: the first contains all elements `x`
1063 for which the function returned `Left x` and the second list contains all elements `y` for which the function
1066 mapEither :: (a -> <e> Either b c) -> [a] -> <e> ([b], [c])
1067 mapEither f list = runProc do
1070 for list (\x -> match f x with
1071 Left v -> addArrayList l v
1072 Right v -> addArrayList r v)
1073 (Java.unsafeCoerce l, Java.unsafeCoerce r)
1075 "`replicate n v` returns a list of length `n` such that each element is a copy of `v`."
1077 replicate :: Integer -> a -> [a]
1078 replicate n v = build (\empty cons ->
1080 aux i l = aux (i-1) (cons l v)
1086 class (FunctorE f) => FunctorM f where
1087 "`mapM f` is equivalent to `sequence . map f`."
1088 mapM :: Monad m => (a -> <e> m b) -> f a -> <e> m (f b)
1089 "Evaluate each action in the sequence from left to right, and collect the results."
1090 sequence :: Monad m => f (m a) -> m (f a)
1091 mapM f l = sequence (map f l)
1095 class (FunctorE m, Monad m) => MonadE m where
1096 bindE :: m a -> (a -> <e> m b) -> <e> m b
1098 instance MonadE Maybe where
1099 bindE Nothing _ = Nothing
1100 bindE (Just v) f = f v
1102 instance MonadE (Either a) where
1103 bindE (Left v) _ = Left v
1104 bindE (Right v) f = f v
1106 instance MonadE [] where
1107 bindE l f = concatMap f l
1111 "Identity function."
1116 Ignores the given value. This function is used in a situation where a function returns
1117 a value in a context where the value is not expected.
1124 ignoreM :: a -> Maybe b
1128 Composes two functions
1131 (.) :: (b -> <e> c) -> (a -> <e> b) -> (a -> <e> c)
1136 "A type class for sequences. All sequences must support indexing by integers."
1137 class /*(Additive a) =>*/ Sequence a where
1138 "Length of the sequence"
1139 length :: a -> Integer
1140 "`take n s` returns the first `n` elements of the sequence `s`."
1141 take :: Integer -> a -> a
1142 "`drop n s` removes the first `n` elements of the sequence `s`."
1143 drop :: Integer -> a -> a
1145 `sub s begin end` returns a subsequence of `s` starting from
1146 index `begin` and ending just before index `end`.
1148 sub :: a -> Integer -> Integer -> a
1150 take n v = sub v 0 (min n (length v))
1151 drop n v = sub v (min n len) len
1155 instance Sequence [a] where
1159 instance Sequence String where
1160 length = lengthString
1163 class IndexedSequence f where
1164 "`seq ! i` returns the `i`th element of the sequence `seq`. Indexing starts from zero."
1165 (!) :: f a -> Integer -> a
1167 "Returns the first element of a sequence"
1172 "Returns the last element of a sequence"
1175 last l = l!(length l-1)
1177 instance IndexedSequence [] where
1183 Equivalent to the boolean value `True`. The value is meant to be used in
1190 otherwise :: Boolean
1193 instance Ord Boolean where
1194 compare False False = 0
1195 compare False True = neg 1
1196 compare True False = 1
1197 compare True True = 0
1199 instance Show Boolean where
1201 show False = "False"
1204 Boolean conjunction (and). The function is a macro that evaluates the second parameter
1205 only if the first parameter is `True`.
1208 <tr><th>a</th><th>b</th><th>a && b</th></tr>
1209 <tr><td>True</td><td>True</td><td>True</td></tr>
1210 <tr><td>True</td><td>False</td><td>False</td></tr>
1211 <tr><td>False</td><td>not evaluated</td><td>False</td></tr>
1215 (&&) :: Boolean -> Boolean -> Boolean
1216 a && b = if a then b else False
1219 Boolean disjunction (or). The function is a macro that evaluates the second parameter
1220 only if the first parameter is `False`.
1223 <tr><th>a</th><th>b</th><th>a || b</th></tr>
1224 <tr><td>True</td><td>not evaluated</td><td>True</td></tr>
1225 <tr><td>False</td><td>True</td><td>True</td></tr>
1226 <tr><td>False</td><td>False</td><td>False</td></tr>
1230 (||) :: Boolean -> Boolean -> Boolean
1231 a || b = if a then True else b
1235 not a = if a then False else True
1239 //data Maybe a = Nothing | Just a
1241 "Given `Just x` this function returns `x`. If the parameter is `Nothing`, the function raises an exception."
1242 fromJust :: Maybe a -> a
1243 fromJust (Just a) = a
1245 deriving instance (Ord a) => Ord (Maybe a)
1246 deriving instance (Show a) => Show (Maybe a)
1248 instance Functor Maybe where
1249 fmap _ Nothing = Nothing
1250 fmap f (Just x) = Just (f x)
1252 instance FunctorE Maybe where
1253 map _ Nothing = Nothing
1254 map f (Just x) = Just (f x)
1257 iter f (Just x) = ignore (f x)
1259 iterI _ Nothing = ()
1260 iterI f (Just x) = ignore (f 0 x)
1262 instance Monad Maybe where
1266 Nothing >>= _ = Nothing
1270 join Nothing = Nothing
1273 instance MonadZero Maybe where
1276 instance MonadOr Maybe where
1277 morelse a@(Just _) _ = a
1280 "`execJust v f` executes the function `f` with parameter value `x`, if `v=Just x`. If `v=Nothing`, the function does nothing."
1282 execJust :: Maybe a -> (a -> <e> b) -> <e> ()
1283 execJust maybeValue procedure = match maybeValue with
1284 Just v -> ignore $ procedure v
1287 "`fromMaybe def v` returns `def` if `v=Nothing` and `x` if `v=Just x`."
1289 fromMaybe :: a -> Maybe a -> a
1290 fromMaybe default maybeValue = match maybeValue with
1294 "`maybe def f v` returns `def` if `v=Nothing` and `f x` if `v=Just x`."
1295 maybe :: b -> (a -> <e> b) -> Maybe a -> <e> b
1296 maybe n _ Nothing = n
1297 maybe _ f (Just x) = f x
1300 Provides a default value if the first parameter is Nothing.
1301 The default value is evaluated only if needed. The function
1302 can be used as an operator and is right associative so that
1303 the following is possible:
1305 tryWithTheFirstMethod
1306 `orElse` tryWithTheSecondMethod
1307 `orElse` fail "Didn't succeed."
1310 orElse :: Maybe a -> (<e> a) -> <e> a
1311 orElse (Just x) _ = x
1312 orElse Nothing def = def
1315 orElseM :: Maybe a -> (<e> Maybe a) -> <e> Maybe a
1316 orElseM mx@(Just x) _ = mx
1317 orElseM Nothing def = def
1322 The Either type represents values with two possibilities: a value of type `Either a b` is either `Left a` or `Right b`.
1324 The `Either` type is sometimes used to represent a value which is either correct or an error; by convention, the `Left` constructor
1325 is used to hold an error value and the `Right` constructor is used to hold a correct value (mnemonic: "right" also means "correct").
1327 @JavaType "org.simantics.scl.runtime.either.Either"
1329 @JavaType "org.simantics.scl.runtime.either.Left"
1332 | @JavaType "org.simantics.scl.runtime.either.Right"
1336 deriving instance (Ord a, Ord b) => Ord (Either a b)
1337 deriving instance (Show a, Show b) => Show (Either a b)
1339 instance Functor (Either a) where
1340 fmap _ (Left x) = Left x
1341 fmap f (Right y) = Right (f y)
1343 instance FunctorE (Either a) where
1344 map _ (Left x) = Left x
1345 map f (Right y) = Right (f y)
1347 iter _ (Left x) = ()
1348 iter f (Right y) = ignore (f y)
1350 iterI _ (Left x) = ()
1351 iterI f (Right y) = ignore (f 0 y)
1353 instance Monad (Either b) where
1356 Left x >>= _ = Left x
1359 join (Left x) = Left x
1364 importJava "java.lang.String" where
1367 concatString :: String -> String -> String
1369 @JavaName "compareTo"
1370 compareString :: String -> String -> Integer
1373 lengthString :: String -> Integer
1376 `replaceString original pattern replacement` replaces all occurrences of `pattern` in the string by `replacement`.
1379 replaceString :: String -> String -> String -> String
1383 splitString_ :: String -> String -> Array String
1386 `indexOf string s` finds the first occurrence of `s` from `string` and returns its index.
1387 If the `s` does not occur in the string, return `-1`."
1390 indexOf :: String -> String -> Integer
1392 "Works like `indexOf` but starts searching from the given index instead of the beginning of the string."
1394 indexOfStartingFrom :: String -> String -> Integer -> Integer
1396 "Works like `indexOf` but returns the index of the last occurrence."
1397 @JavaName lastIndexOf
1398 lastIndexOf :: String -> String -> Integer
1400 "Works like `lastIndexOf` but starts searching from the given index instead of the end of the string."
1401 @JavaName lastIndexOf
1402 lastIndexOfStartingFrom :: String -> String -> Integer -> Integer
1406 subString :: String -> Integer -> Integer -> String
1409 `regionMatches str1 offset1 str2 offset2 len` tests whether
1410 `sub str1 offset1 (offset1+len) == sub str2 offset2 (offset2+len)`.
1412 regionMatches :: String -> Integer -> String -> Integer -> Integer -> Boolean
1414 "`startsWith string prefix` returns true if the string begins with the given prefix."
1415 startsWith :: String -> String -> Boolean
1417 "`endsWith string suffix` returns true if the string ends with the given prefix."
1418 endsWith :: String -> String -> Boolean
1420 "Removes leading and trailing whitespace from the string."
1421 trim :: String -> String
1423 "`contains string s` returns true if `string` contains `s` as a substring."
1424 contains :: String -> String -> Boolean
1426 "`charAt string i` returns the `i`th character of the string."
1427 charAt :: String -> Integer -> Character
1429 "Converts all letters of the string to lower case."
1430 toLowerCase :: String -> String
1431 "Converts all letters of the string to upper case."
1432 toUpperCase :: String -> String
1434 "Creates a string from a vector of characters."
1436 string :: Vector Character -> String
1438 getBytes :: String -> String -> ByteArray
1440 getBytesUTF8 :: String -> ByteArray
1441 getBytesUTF8 str = getBytes str "UTF-8"
1443 instance Ord String where
1444 compare = compareString
1446 instance Additive String where
1449 sum ss = runProc (StringBuilder.toString $ foldl StringBuilder.appendString StringBuilder.new ss)
1452 importJava "org.simantics.scl.runtime.string.StringEscape" where
1453 appendEscapedString :: StringBuilder.T -> String -> <Proc> StringBuilder.T
1455 instance Show String where
1456 showForPrinting = id
1457 sb <+ v = (appendEscapedString (sb << "\"") v) << "\""
1459 instance Read String where
1462 @deprecated "Instead of 'splitString text pattern', write 'split pattern text' (note change in the parameter order)."
1463 "`splitString text pattern` splits the string into a list of string where the parts are sepratated in the original list by the given pattern."
1464 splitString :: String -> String -> [String]
1465 splitString source pattern = arrayToList $ splitString_ source pattern
1468 `split pattern text` splits `text` around matches of the given regular expression `pattern`.
1470 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.
1472 The string "boo:and:foo", for example, yields the following results with these expressions:
1475 : { "boo", "and", "foo" }
1476 o { "b", "", ":and:f" }
1478 split :: String -> String -> [String]
1479 split pattern text = arrayToList $ splitString_ text pattern
1483 instance Ord () where
1486 instance Additive () where
1490 instance Show () where
1495 "Gives the first element of a pair."
1500 "Gives the second element of a pair."
1506 mapFst :: (a -> b) -> (a,c) -> (b,c)
1507 mapFst f (x,y) = (f x, y)
1510 mapSnd :: (a -> b) -> (c,a) -> (c,b)
1511 mapSnd f (x,y) = (x, f y)
1513 instance (Ord a, Ord b) => Ord (a, b) where
1514 compare (a0, b0) (a1, b1) = compare a0 a1 &<& compare b0 b1
1516 instance (Additive a, Additive b) => Additive (a, b) where
1518 (a0, b0) + (a1, b1) = (a0+a1, b0+b1)
1520 instance Functor ((,) a) where
1521 fmap f (a,b) = (a, f b)
1523 instance (Show a, Show b) => Show (a, b) where
1524 sb <+ (x, y) = sb << "(" <+ x << ", " <+ y << ")"
1528 instance (Ord a, Ord b, Ord c) => Ord (a, b, c) where
1529 compare (a0, b0, c0) (a1, b1, c1) = compare a0 a1 &<& compare b0 b1 &<& compare c0 c1
1531 instance (Additive a, Additive b, Additive c) => Additive (a, b, c) where
1532 zero = (zero, zero, zero)
1533 (a0, b0, c0) + (a1, b1, c1) = (a0+a1, b0+b1, c0+c1)
1535 instance Functor ((,,) a b) where
1536 fmap f (a,b,c) = (a, b, f c)
1538 instance (Show a, Show b, Show c) => Show (a, b, c) where
1539 sb <+ (x, y, z) = sb << "(" <+ x << ", " <+ y << ", " <+ z << ")"
1543 instance (Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d) where
1544 compare (a0, b0, c0, d0) (a1, b1, c1, d1) =
1545 compare a0 a1 &<& compare b0 b1 &<& compare c0 c1 &<& compare d0 d1
1547 instance (Additive a, Additive b, Additive c, Additive d) => Additive (a, b, c, d) where
1548 zero = (zero, zero, zero, zero)
1549 (a0, b0, c0, d0) + (a1, b1, c1, d1) = (a0+a1, b0+b1, c0+c1, d0+d1)
1551 instance Functor ((,,,) a b c) where
1552 fmap f (a,b,c,d) = (a, b, c, f d)
1554 instance (Show a, Show b, Show c, Show d) => Show (a, b, c, d) where
1555 sb <+ (x, y, z, w) = sb << "(" <+ x << ", " <+ y << ", " <+ z << ", " <+ w << ")"
1559 instance (Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e) where
1560 compare (a0, b0, c0, d0, e0) (a1, b1, c1, d1, e1) =
1561 compare a0 a1 &<& compare b0 b1 &<& compare c0 c1 &<& compare d0 d1 &<& compare e0 e1
1563 instance (Additive a, Additive b, Additive c, Additive d, Additive e) => Additive (a, b, c, d, e) where
1564 zero = (zero, zero, zero, zero, zero)
1565 (a0, b0, c0, d0, e0) + (a1, b1, c1, d1, e1) = (a0+a1, b0+b1, c0+c1, d0+d1, e0+e1)
1567 instance Functor ((,,,,) a b c d) where
1568 fmap f (a,b,c,d,e) = (a, b, c, d, f e)
1572 instance (Ord a) => Ord [a] where
1573 compare a b = loop 0
1578 then (if i >= lB then 0 else -1)
1581 else compare (a!i) (b!i) &<& loop (i+1)
1583 instance Functor [] where
1586 instance FunctorE [] where
1591 instance Monad [] where
1592 return x = singletonList x
1593 l >>= f = concatMap f l
1596 instance MonadZero [] where
1599 instance MonadPlus [] where
1602 instance Additive [a] where
1606 instance FunctorM [] where
1607 sequence = foldl (\m mel -> m >>= \l -> mel >>= \el -> return (addList l el)) (return emptyList)
1608 mapM f l = sequence (map f l)
1610 "Appends the string representations of all elements of the list to the string builder and separates the values with the given separator."
1611 printWithSeparator :: Show a => StringBuilder.T -> String -> [a] -> <Proc> StringBuilder.T
1612 printWithSeparator sb sep l = loop 0
1615 loop i = if i >= len then sb
1617 (if i==0 then sb else sb << sep) <+ l!i
1621 Joins the string representations of the list of values with the given separator.
1623 See [intercalate](#intercalate) for an alternative that works with Strings
1624 and doesn't escape its arguments.
1626 joinWithSeparator :: Show a => String -> [a] -> String
1627 joinWithSeparator separator values = runProc (
1628 StringBuilder.toString $ printWithSeparator StringBuilder.new separator values)
1632 The intercalate function takes a String and a list of Strings
1633 and concatenates the list after interspersing the first argument
1634 between each element of the list.
1636 See also more generic [joinWithSeparator](#joinWithSeparator)
1637 which escapes its arguments using `show`.
1639 intercalate :: String -> [String] -> String
1640 intercalate separator strings = do
1647 sb = StringBuilder.new
1649 loop i | i == l = ()
1651 sb << separator << strings!i
1654 StringBuilder.toString sb
1656 instance (Show a) => Show [a] where
1661 if (i>0) then sb << ", " else sb
1668 importJava "java.util.List" where
1669 "`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."
1671 getList :: [a] -> Integer -> a
1675 lengthList :: [a] -> Integer
1678 subList :: [a] -> Integer -> Integer -> [a]
1681 isEmpty :: [a] -> Boolean
1684 importJava "java.util.Collections" where
1686 //singletonList :: a -> [a]
1691 emptyList = build (\empty cons -> empty)
1694 "Creates a list with exectly one element."
1696 singletonList :: a -> [a]
1697 singletonList v = build (\empty cons -> cons empty v)
1700 // foldl f i (a + b) = foldl f (foldl f i a) b
1702 appendList :: [a] -> [a] -> [a]
1703 appendList a b = build (\empty cons -> foldl cons (foldl cons empty a) b)
1706 importJava "org.simantics.scl.runtime.list.ShareableList" where
1707 "Concatenates two lists."
1710 appendList :: [a] -> [a] -> [a]
1712 "Adds the given value to the end of the list."
1714 addList :: [a] -> a -> [a]
1717 importJava "java.util.ArrayList" where
1721 newArrayList :: <Proc> ArrayList a
1724 addArrayList :: ArrayList a -> a -> <Proc> ()
1727 A primitive for constructing a list by `empty` and `cons` operations given to the function given as a parameter to this function.
1730 build (\empty cons -> cons (cons (cons empty 1) 2) 3)
1736 The SCL compiler makes the following optimization when encountering `build` and `foldl` functions after inlining:
1738 foldl f i (build g) = g i f
1741 build :: forall b e2. (forall a e1. a -> (a -> b -> <e1> a) -> <e1,e2> a) -> <e2> [b]
1742 build f = runProc do
1744 f () (\_ v -> addArrayList l v)
1747 "A specific implementation of `map` for lists."
1750 mapEList :: (a -> <e> b) -> [a] -> <e> [b]
1751 mapEList f l = build (\empty cons -> foldl (\cur x -> cons cur (f x)) empty l)
1753 "A specific implementation of `fmap` for lists."
1755 mapList :: (a -> b) -> [a] -> [b]
1756 mapList f l = build (\empty cons -> foldl (\cur x -> cons cur (f x)) empty l)
1758 "`guardList v` returns a singleton `[()]` if `v=True` and the empty list if `v=False`."
1760 guardList :: Boolean -> [()]
1761 guardList cond = build (\empty cons -> if cond then cons empty () else empty)
1764 `concatMap` combines `map` and `join` functions.
1765 It maps the elements of a given list to lists with the given function and concatenates the results.
1767 concatMap f lst = join (map f lst) = [y | x <- lst, y <- f x]
1770 concatMap :: (a -> <e> [b]) -> [a] -> <e> [b]
1771 concatMap f l = build (\empty cons -> foldl (\cur le -> foldl cons cur (f le)) empty l)
1774 Applies the given function to the elements of the lists until the function returns something
1775 else than `Nothing`. This return value is also returned as a result of this function.
1778 mapFirst :: (a -> <e> Maybe b) -> [a] -> <e> Maybe b
1779 mapFirst f l = loop 0
1782 loop i = if i == len
1784 else match f (l!i) with
1786 Nothing -> loop (i+1)
1789 foldl op initialValue list
1791 applies a binary operator `op` to all elements of `list` from left to right
1792 starting with `initialValue`. For example,
1794 foldl op init [x1, x2, x3, x4] = (((init `op` x1) `op` x2) `op` x3) `op` x4
1797 foldl :: forall a b e. (a -> b -> <e> a) -> a -> [b] -> <e> a
1798 foldl f initial l = loop initial 0
1801 loop cur i = if i==len
1803 else loop (f cur (l!i)) (i+1)
1805 foldlI :: forall a b e. (Integer -> a -> b -> <e> a) -> a -> [b] -> <e> a
1806 foldlI f initial l = loop initial 0
1809 loop cur i = if i==len
1811 else loop (f i cur (l!i)) (i+1)
1813 scanl :: (b -> a -> <e> b) -> b -> [a] -> <e> [b]
1814 scanl f initial l = build (\empty cons -> let
1816 loop cur i accum = let nl = cons accum cur
1819 else loop (f cur (l!i)) (i+1) nl
1820 in loop initial 0 empty)
1822 "`foldr` is defined like `foldl` but it process the list from right to left."
1824 foldr :: (b -> a -> <e> a) -> a -> [b] -> <e> a
1825 foldr f initial l = loop initial (length l - 1)
1827 loop cur i = if i < 0
1829 else loop (f (l!i) cur) (i-1)
1831 foldr1 :: (a -> a -> <e> a) -> [a] -> <e> a
1832 foldr1 f l = loop (l!(len-1)) (len-2)
1835 loop cur i = if i < 0
1837 else loop (f (l!i) cur) (i-1)
1840 `filter pred lst` returns those elements of `lst` that the predicate `pred` accepts. For example
1842 filter (> 3) [1, 2, 3, 4, 5, 6] = [4, 5, 6]
1845 filter :: (a -> <e> Boolean) -> [a] -> <e> [a]
1846 filter p l = build (\empty cons -> foldl (\cur x -> if p x then cons cur x else cur) empty l)
1849 Takes those elements of the input list that match `(Just x)` and adds the contents to the resulting list. For example,
1851 filterJust [Just 1, Nothing, Just 5] = [1, 5]
1854 filterJust :: [Maybe a] -> [a]
1855 filterJust l = build (\empty cons -> foldl (\cur x -> match x with Just v -> cons cur v ; _ -> cur) empty l)
1857 listToMaybe :: [a] -> Maybe a
1858 listToMaybe l = if isEmpty l then Nothing else Just (l!0)
1860 maybeToList :: Maybe a -> [a]
1861 maybeToList (Just a) = [a]
1865 `takeWhile p l`, returns the longest prefix (possibly empty) of list `l` of elements that satisfy `p`
1867 takeWhile :: (a -> <e> Boolean) -> [a] -> <e> [a]
1868 takeWhile f l = loop 0
1871 loop i | i == len = l
1872 | f (l!i) = loop (i+1)
1873 | otherwise = take i l
1875 partition :: (a -> <e> Boolean) -> [a] -> <e> ([a], [a])
1876 partition p l = runProc do
1881 then addArrayList res1 el
1882 else addArrayList res2 el
1884 (Java.unsafeCoerce res1, Java.unsafeCoerce res2)
1887 `range begin end` produces a list of consecutive integers starting from `begin` and ending to `end` (including `end`).
1888 The compiler supports syntactic sugar `[begin..end]` for this function.
1891 range :: Integer -> Integer -> [Integer]
1892 range first last = build (\empty cons -> do
1893 loop i cur = if i > last then cur else loop (i+1) (cons cur i)
1896 "A specific implementation of `iter` for lists."
1898 iterList :: (a -> <e> b) -> [a] -> <e> ()
1899 iterList f l = foldl (\_ x -> ignore (f x)) () l
1901 "A specific implementation of `iterI` for lists."
1903 iterIList :: (Integer -> a -> <e> b) -> [a] -> <e> ()
1904 iterIList f l = do foldl (\i x -> do f i x ; i+1) 0 l ; ()
1907 Generates a list from a given starting state and iteration function.
1910 let nextState 0 = Nothing
1911 nextState i = Just (i, i `div` 2)
1912 in unfoldr nextState 30
1919 unfoldr :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1920 unfoldr f s = build (\empty cons -> do
1923 Just (el,newS) -> loop newS (cons cur el)
1927 importJava "org.simantics.scl.runtime.Lists" where
1931 mapList :: (a -> b) -> [a] -> [b]
1934 mapEList :: (a -> <e> b) -> [a] -> <e> [b]
1937 iterList :: (a -> <e> ()) -> [a] -> <e> ()
1938 concatMap :: (a -> <e> [b]) -> [a] -> <e> [b]
1941 Combines two lists into one list of pairs. The length of the resulting list is the length of the smallest input list.
1943 zip [1, 2, 3, 4, 5] ['a', 'b', 'c'] = [(1, 'a'), (2, 'b'), (3, 'c')]
1945 zip :: [a] -> [b] -> [(a,b)]
1946 "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."
1947 zipWith :: (a -> b -> <e> c) -> [a] -> [b] -> <e> [c]
1949 Produces two lists from one list of pairs.
1951 unzip [(1, 'a'), (2, 'b'), (3, 'c')] = ([1, 2, 3], ['a', 'b', 'c'])
1953 unzip :: [(a,b)] -> ([a],[b])
1955 //"@filter p l@ returns those elements of @l@ that the predicate @p@ accepts."
1956 //filter :: (a -> <e> Boolean) -> [a] -> <e> [a]
1957 //filterJust :: [Maybe a] -> [a]
1959 foldl :: (a -> b -> <e> a) -> a -> [b] -> <e> a
1961 "Like `foldl` but assumes that the list is non-empty so the initial is not needed."
1962 foldl1 :: (a -> a -> <e> a) -> [a] -> <e> a
1963 //unfoldr :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1965 "Sorts the list using the given comparator."
1966 sortWith :: (a -> a -> <e> Integer) -> [a] -> <e> [a]
1969 Given a list of key-value pairs, the function produces a function that finds a value
1970 efficiently for the given key.
1972 index :: [(a,b)] -> a -> Maybe b
1975 Given a list of elements, the function produces its characteristic function.
1977 indexSet :: [a] -> a -> Boolean
1980 Given a list of values and a function computing a key for each value, the function produces a function that finds a value
1981 effeciently for the given key.
1983 indexBy :: (a -> <e> b) -> [a] -> <e> (b -> Maybe a)
1985 "Works like `index` but uses the given functions as hash codes and equality."
1986 indexWith :: (a -> Integer) -> (a -> a -> Boolean) -> [(a,b)] -> a -> Maybe b
1988 "Groups a list values by a key computed by the given function."
1989 groupBy :: (a -> <e> b) -> [a] -> <e> [(b, [a])]
1991 "Groups a list of key-value pairs by the keys."
1992 group :: [(a,b)] -> [(a, [b])]
1994 "Composition of index and groupBy."
1995 indexGroupBy :: (a -> <e> b) -> [a] -> <e> (b -> [a])
1997 "Composition of index and group."
1998 indexGroup :: [(a,b)] -> a -> [b]
2000 groupWith :: (b -> Integer) -> (b -> b -> Boolean) -> (a -> <e> b) -> (a -> <e> c) -> [a] -> <e> [(b, [c])]
2002 "Removes duplicates (all but the first occurrence) from the list but otherwise preserves the order of the elements."
2003 unique :: [a] -> [a]
2005 "Like `unique`, but uses the given function for finding the key values used for uniqueness testing."
2006 uniqueBy :: (a -> <e> b) -> [a] -> <e> [a]
2008 "Works like `unique` but uses the given function for equality tests."
2009 uniqueWith :: (a -> a -> Boolean) -> [a] -> [a]
2011 "Works like `\\\\` but uses the given function for equality tests."
2012 deleteAllBy :: (a -> a -> Boolean) -> [a] -> [a] -> [a]
2015 listDifference :: [a] -> [a] -> [a]
2017 //range :: Integer -> Integer -> [Integer]
2019 //build :: (forall a. a -> (a -> b -> <e> a) -> <e> a) -> <e> [b]
2021 "`elem el lst` return true, if `el` occurs in the list `lst`."
2022 elem :: a -> [a] -> Boolean
2026 loop i | i < len = if el == l!i
2031 "`elemMaybe v1 (Just v2)` returns true if `v1 == v2`. `elemMaybe v1 Nothing` is always false."
2032 elemMaybe :: a -> Maybe a -> Boolean
2033 elemMaybe el m = match m with
2034 Just el2 -> el == el2
2037 "`elemIndex el lst` returns the index of the first element in the given list `lst` which is equal (by ==) to the query element, or Nothing if there is no such element."
2038 elemIndex :: a -> [a] -> Maybe Integer
2039 elemIndex el l = loop 0
2042 loop i | i < len = if el == l!i
2045 | otherwise = Nothing
2048 Computes a list that contains only elements that belongs to both input lists.
2050 intersect :: [a] -> [a] -> [a]
2051 intersect a b = filter f a
2055 "Reverses a given list. For example, `reverse [1,2,3] = [3,2,1]`"
2056 reverse :: [a] -> [a]
2057 reverse l = [l!(len-i) | i <- [1..len]]
2062 Transposes the rows and columns of its argument. For example,
2064 transpose [[1,2,3],[4,5,6]] == [[1,4],[2,5],[3,6]]
2065 transpose [[1,2],[3,4,5]] == [[1,3],[2,4],[5]]
2067 transpose :: [[a]] -> [[a]]
2068 transpose xss = [[xs!i | xs <- xss, i < length xs]
2069 | i <- [0..maximum [length xs | xs <- xss]-1]]
2071 "Works like `unfoldr` but generates the list from right to left."
2072 unfoldl :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
2073 unfoldl f seed = reverse $ unfoldr f seed
2075 "Removes the first element of the list, if the list is non-empty."
2077 tail l = if len < 2 then emptyList else subList l 1 len
2081 "Tries to find the given key from the list of key-value pairs and returns the corresponding value."
2082 lookup :: a -> [(a, b)] -> Maybe b
2087 (a,b) | a == el -> Just b
2088 | otherwise -> loop (i+1)
2092 "Conjunction over a list."
2094 and :: [Boolean] -> Boolean
2095 and = foldl (&&) True
2097 "Disjunction over a list."
2099 or :: [Boolean] -> Boolean
2100 or = foldl (||) False
2103 `any pred lst` tests whether the predicate `pred` holds some element of `lst`.
2104 It returns immediately when it encounters the first value satisfying the predicate.
2106 any :: (a -> <e> Boolean) -> [a] -> <e> Boolean
2110 `all pred lst` tests whether the predicate `pred` holds for all elements of `lst`.
2111 It returns immediately when it encounters the first value not satisfying the predicate.
2113 all :: (a -> <e> Boolean) -> [a] -> <e> Boolean
2117 Returns the first element of the list satisfying the given condition,
2118 or `Nothing` if there is no such element.
2120 findFirst :: (a -> <e> Boolean) -> [a] -> <e> Maybe a
2121 findFirst p l = loop 0
2125 then let el = l!i in
2134 Sorts the given list using its default order.
2137 sort :: Ord a => [a] -> [a]
2138 sort = sortWith compare
2141 Sorts the lists by the values computed by the first function.
2144 sortBy snd [(1,5), (2,3), (3,4)] = [(2,3), (3,4), (1,5)]
2147 sortBy :: Ord b => (a -> <e> b) -> [a] -> <e> [a]
2148 sortBy f l = sortWith (\x y -> compare (f x) (f y)) l
2149 // This is faster if f is slow, but will generate more auxiliary structures
2150 //sortBy f l = map snd (sortWith (\(x,_) (y,_) -> compare x y) [(f x, x) | x <- l])
2152 "`a \\\\ b` removes all elements of `b` from the list `a`."
2153 (\\) :: [a] -> [a] -> [a]
2154 (\\) = listDifference
2158 importJava "java.lang.Object" where
2159 "A data type that can represent any value."
2164 showDynamic :: Dynamic -> String
2166 instance Show Dynamic where
2169 "Converts a value to `Dynamic` type."
2170 toDynamic :: a -> Dynamic
2171 toDynamic = Java.unsafeCoerce
2173 "Converts a `Dynamic` value to a required value, or fails if the conversion is not possible."
2174 importJava "org.simantics.scl.compiler.runtime.ValueConversion" where
2175 fromDynamic :: Typeable a => Dynamic -> a
2179 importJava "org.simantics.scl.runtime.procedure.Ref" where
2180 "A mutable reference to a value of type `a`."
2183 "Creates a new reference with the given initial value."
2185 ref :: a -> <Proc> (Ref a)
2187 "Returns the current value of the reference."
2189 getRef :: Ref a -> <Proc> a
2191 "Sets a new value for the reference."
2192 @JavaName "<set>value"
2193 (:=) :: Ref a -> a -> <Proc> ()
2195 instance Show (Ref a) where
2196 show _ = "<reference>"
2198 importJava "org.simantics.scl.runtime.reporting.SCLReporting" where
2199 "Prints the given string to the console."
2201 printString :: String -> <Proc> ()
2202 "Prints an error message to the console."
2203 printError :: String -> <Proc> ()
2204 "Reports that certain amount of work has been done for the current task."
2205 didWork :: Double -> <Proc> ()
2207 `printingToFile "fileName" expression` executes the `expression` so that all its console prints
2208 are written to the file given as a first parameter.
2210 printingToFile :: String -> (<e> a) -> <e> a
2212 `printErrorsAsNormalPrints expression` executes the `expression` so that all its error prints
2213 are printed as normal prints. This is useful mainly in testing scripts for checking that the implementations
2214 give proper error messages with invalid inputs.
2216 printErrorsAsNormalPrints :: (<e> a) -> <e> a
2218 `disablePrintingForCommand expression` executes the `expression` so that it does not print return values.
2219 Errors are printed normally.
2221 disablePrintingForCommand :: (<e> a) -> <e> a
2224 importJava "org.simantics.scl.runtime.procedure.Procedures" where
2225 "Returns `True` if the current thread has been interrupted."
2226 isInterrupted :: <Proc> Boolean
2227 "Checks whether the current thread has been interrupted and throws an exception if it is."
2228 checkInterrupted :: <Proc> ()
2229 "Generates a random identifier."
2230 generateUID :: <Proc> String
2232 "Executes the given expression and catches certain class of exceptions (specified by the catch handler that is given as a second parameter.)"
2234 catch :: VecComp ex => (<e,Exception> a) -> (ex -> <e> a) -> <e> a
2236 importJava "java.lang.Throwable" where
2240 showThrowable :: Throwable -> String
2242 @JavaName getMessage
2243 getMessageThrowable :: Throwable -> String
2246 getCauseThrowable :: Throwable -> Maybe Throwable
2247 importJava "java.lang.Exception" where
2251 showException :: Exception -> String
2253 instance Show Throwable where
2254 show = showThrowable
2255 instance Show Exception where
2256 show = showException
2258 class Throwable e where
2259 toThrowable :: e -> Throwable
2261 messageOfException :: Throwable e => e -> String
2262 messageOfException = getMessageThrowable . toThrowable
2264 causeOfException :: Throwable e => e -> Maybe Throwable
2265 causeOfException = getCauseThrowable . toThrowable
2267 instance Throwable Throwable where
2269 instance Throwable Exception where
2270 toThrowable = Java.unsafeCoerce
2272 "Prints the given value in the console."
2274 print :: Show a => a -> <Proc> ()
2275 print v = printString (showForPrinting v)
2277 instance Show TypeRep where
2278 sb <+ (TApply (TCon "Builtin" "[]") b) =
2279 sb << "[" <+ b << "]"
2280 sb <+ (TApply (TApply (TCon "Builtin" "(,)") c1) c2) =
2281 sb << "(" <+ c1 << "," <+ c2 << ")"
2282 sb <+ (TApply (TApply (TApply (TCon "Builtin" "(,,)") c1) c2) c3) =
2283 sb << "(" <+ c1 << "," <+ c2 << "," <+ c3 << ")"
2284 sb <+ (TApply (TApply (TApply (TApply (TCon "Builtin" "(,,,)") c1) c2) c3) c4) =
2285 sb << "(" <+ c1 << "," <+ c2 << "," <+ c3 << "," <+ c4 << ")"
2287 sb <+ (TCon _ name) = sb << name
2288 sb <+ (TApply a b) = sb <+ Par 1 a << " " <+ Par 2 b
2289 sb <+ (TFun a b) = sb <+ Par 1 a << " -> " <+ b
2291 precedence (TCon _ _) = 0
2292 precedence (TFun _ _) = 2
2293 precedence (TApply a _) = if isSpecialType a then 0 else 1
2295 isSpecialType (TCon "Builtin" "[]") = True
2296 isSpecialType (TCon "Builtin" "()") = True
2297 isSpecialType (TCon "Builtin" "(,)") = True
2298 isSpecialType (TCon "Builtin" "(,,)") = True
2299 isSpecialType (TCon "Builtin" "(,,,)") = True
2300 isSpecialType (TApply a _) = isSpecialType a
2306 importJava "org.simantics.scl.compiler.types.Type" where
2308 showType :: Type -> String
2310 importJava "org.simantics.scl.compiler.types.Types" where
2311 removeForAll :: Type -> Type
2313 instance Show Type where