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"
1171 "Returns the last element of a sequence"
1173 last l = l!(length l-1)
1175 instance IndexedSequence [] where
1181 Equivalent to the boolean value `True`. The value is meant to be used in
1188 otherwise :: Boolean
1191 instance Ord Boolean where
1192 compare False False = 0
1193 compare False True = neg 1
1194 compare True False = 1
1195 compare True True = 0
1197 instance Show Boolean where
1199 show False = "False"
1202 Boolean conjunction (and). The function is a macro that evaluates the second parameter
1203 only if the first parameter is `True`.
1206 <tr><th>a</th><th>b</th><th>a && b</th></tr>
1207 <tr><td>True</td><td>True</td><td>True</td></tr>
1208 <tr><td>True</td><td>False</td><td>False</td></tr>
1209 <tr><td>False</td><td>not evaluated</td><td>False</td></tr>
1213 (&&) :: Boolean -> Boolean -> Boolean
1214 a && b = if a then b else False
1217 Boolean disjunction (or). The function is a macro that evaluates the second parameter
1218 only if the first parameter is `False`.
1221 <tr><th>a</th><th>b</th><th>a || b</th></tr>
1222 <tr><td>True</td><td>not evaluated</td><td>True</td></tr>
1223 <tr><td>False</td><td>True</td><td>True</td></tr>
1224 <tr><td>False</td><td>False</td><td>False</td></tr>
1228 (||) :: Boolean -> Boolean -> Boolean
1229 a || b = if a then True else b
1233 not a = if a then False else True
1237 //data Maybe a = Nothing | Just a
1239 "Given `Just x` this function returns `x`. If the parameter is `Nothing`, the function raises an exception."
1240 fromJust :: Maybe a -> a
1241 fromJust (Just a) = a
1243 deriving instance (Ord a) => Ord (Maybe a)
1244 deriving instance (Show a) => Show (Maybe a)
1246 instance Functor Maybe where
1247 fmap _ Nothing = Nothing
1248 fmap f (Just x) = Just (f x)
1250 instance FunctorE Maybe where
1251 map _ Nothing = Nothing
1252 map f (Just x) = Just (f x)
1255 iter f (Just x) = ignore (f x)
1257 iterI _ Nothing = ()
1258 iterI f (Just x) = ignore (f 0 x)
1260 instance Monad Maybe where
1264 Nothing >>= _ = Nothing
1268 join Nothing = Nothing
1271 instance MonadZero Maybe where
1274 instance MonadOr Maybe where
1275 morelse a@(Just _) _ = a
1278 "`execJust v f` executes the function `f` with parameter value `x`, if `v=Just x`. If `v=Nothing`, the function does nothing."
1280 execJust :: Maybe a -> (a -> <e> b) -> <e> ()
1281 execJust maybeValue procedure = match maybeValue with
1282 Just v -> ignore $ procedure v
1285 "`fromMaybe def v` returns `def` if `v=Nothing` and `x` if `v=Just x`."
1287 fromMaybe :: a -> Maybe a -> a
1288 fromMaybe default maybeValue = match maybeValue with
1294 Provides a default value if the first parameter is Nothing.
1295 The default value is evaluated only if needed. The function
1296 can be used as an operator and is right associative so that
1297 the following is possible:
1299 tryWithTheFirstMethod
1300 `orElse` tryWithTheSecondMethod
1301 `orElse` fail "Didn't succeed."
1304 orElse :: Maybe a -> (<e> a) -> <e> a
1305 orElse (Just x) _ = x
1306 orElse Nothing def = def
1309 orElseM :: Maybe a -> (<e> Maybe a) -> <e> Maybe a
1310 orElseM mx@(Just x) _ = mx
1311 orElseM Nothing def = def
1316 The Either type represents values with two possibilities: a value of type `Either a b` is either `Left a` or `Right b`.
1318 The `Either` type is sometimes used to represent a value which is either correct or an error; by convention, the `Left` constructor
1319 is used to hold an error value and the `Right` constructor is used to hold a correct value (mnemonic: "right" also means "correct").
1321 @JavaType "org.simantics.scl.runtime.either.Either"
1323 @JavaType "org.simantics.scl.runtime.either.Left"
1326 | @JavaType "org.simantics.scl.runtime.either.Right"
1330 deriving instance (Ord a, Ord b) => Ord (Either a b)
1331 deriving instance (Show a, Show b) => Show (Either a b)
1333 instance Functor (Either a) where
1334 fmap _ (Left x) = Left x
1335 fmap f (Right y) = Right (f y)
1337 instance FunctorE (Either a) where
1338 map _ (Left x) = Left x
1339 map f (Right y) = Right (f y)
1341 iter _ (Left x) = ()
1342 iter f (Right y) = ignore (f y)
1344 iterI _ (Left x) = ()
1345 iterI f (Right y) = ignore (f 0 y)
1347 instance Monad (Either b) where
1350 Left x >>= _ = Left x
1353 join (Left x) = Left x
1358 importJava "java.lang.String" where
1361 concatString :: String -> String -> String
1363 @JavaName "compareTo"
1364 compareString :: String -> String -> Integer
1367 lengthString :: String -> Integer
1370 `replaceString original pattern replacement` replaces all occurrences of `pattern` in the string by `replacement`.
1373 replaceString :: String -> String -> String -> String
1377 splitString_ :: String -> String -> Array String
1380 `indexOf string s` finds the first occurrence of `s` from `string` and returns its index.
1381 If the `s` does not occur in the string, return `-1`."
1384 indexOf :: String -> String -> Integer
1386 "Works like `indexOf` but starts searching from the given index instead of the beginning of the string."
1388 indexOfStartingFrom :: String -> String -> Integer -> Integer
1390 "Works like `indexOf` but returns the index of the last occurrence."
1391 @JavaName lastIndexOf
1392 lastIndexOf :: String -> String -> Integer
1394 "Works like `lastIndexOf` but starts searching from the given index instead of the end of the string."
1395 @JavaName lastIndexOf
1396 lastIndexOfStartingFrom :: String -> String -> Integer -> Integer
1400 subString :: String -> Integer -> Integer -> String
1403 `regionMatches str1 offset1 str2 offset2 len` tests whether
1404 `sub str1 offset1 (offset1+len) == sub str2 offset2 (offset2+len)`.
1406 regionMatches :: String -> Integer -> String -> Integer -> Integer -> Boolean
1408 "`startsWith string prefix` returns true if the string begins with the given prefix."
1409 startsWith :: String -> String -> Boolean
1411 "`endsWith string suffix` returns true if the string ends with the given prefix."
1412 endsWith :: String -> String -> Boolean
1414 "Removes leading and trailing whitespace from the string."
1415 trim :: String -> String
1417 "`contains string s` returns true if `string` contains `s` as a substring."
1418 contains :: String -> String -> Boolean
1420 "`charAt string i` returns the `i`th character of the string."
1421 charAt :: String -> Integer -> Character
1423 "Converts all letters of the string to lower case."
1424 toLowerCase :: String -> String
1425 "Converts all letters of the string to upper case."
1426 toUpperCase :: String -> String
1428 "Creates a string from a vector of characters."
1430 string :: Vector Character -> String
1432 getBytes :: String -> String -> ByteArray
1434 getBytesUTF8 :: String -> ByteArray
1435 getBytesUTF8 str = getBytes str "UTF-8"
1437 instance Ord String where
1438 compare = compareString
1440 instance Additive String where
1443 sum ss = runProc (StringBuilder.toString $ foldl StringBuilder.appendString StringBuilder.new ss)
1446 importJava "org.simantics.scl.runtime.string.StringEscape" where
1447 appendEscapedString :: StringBuilder.T -> String -> <Proc> StringBuilder.T
1449 instance Show String where
1450 showForPrinting = id
1451 sb <+ v = (appendEscapedString (sb << "\"") v) << "\""
1453 instance Read String where
1456 @deprecated "Instead of 'splitString text pattern', write 'split pattern text' (note change in the parameter order)."
1457 "`splitString text pattern` splits the string into a list of string where the parts are sepratated in the original list by the given pattern."
1458 splitString :: String -> String -> [String]
1459 splitString source pattern = arrayToList $ splitString_ source pattern
1462 `split pattern text` splits `text` around matches of the given regular expression `pattern`.
1464 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.
1466 The string "boo:and:foo", for example, yields the following results with these expressions:
1469 : { "boo", "and", "foo" }
1470 o { "b", "", ":and:f" }
1472 split :: String -> String -> [String]
1473 split pattern text = arrayToList $ splitString_ text pattern
1477 instance Ord () where
1480 instance Additive () where
1484 instance Show () where
1489 "Gives the first element of a pair."
1494 "Gives the second element of a pair."
1500 mapFst :: (a -> b) -> (a,c) -> (b,c)
1501 mapFst f (x,y) = (f x, y)
1504 mapSnd :: (a -> b) -> (c,a) -> (c,b)
1505 mapSnd f (x,y) = (x, f y)
1507 instance (Ord a, Ord b) => Ord (a, b) where
1508 compare (a0, b0) (a1, b1) = compare a0 a1 &<& compare b0 b1
1510 instance (Additive a, Additive b) => Additive (a, b) where
1512 (a0, b0) + (a1, b1) = (a0+a1, b0+b1)
1514 instance Functor ((,) a) where
1515 fmap f (a,b) = (a, f b)
1517 instance (Show a, Show b) => Show (a, b) where
1518 sb <+ (x, y) = sb << "(" <+ x << ", " <+ y << ")"
1522 instance (Ord a, Ord b, Ord c) => Ord (a, b, c) where
1523 compare (a0, b0, c0) (a1, b1, c1) = compare a0 a1 &<& compare b0 b1 &<& compare c0 c1
1525 instance (Additive a, Additive b, Additive c) => Additive (a, b, c) where
1526 zero = (zero, zero, zero)
1527 (a0, b0, c0) + (a1, b1, c1) = (a0+a1, b0+b1, c0+c1)
1529 instance Functor ((,,) a b) where
1530 fmap f (a,b,c) = (a, b, f c)
1532 instance (Show a, Show b, Show c) => Show (a, b, c) where
1533 sb <+ (x, y, z) = sb << "(" <+ x << ", " <+ y << ", " <+ z << ")"
1537 instance (Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d) where
1538 compare (a0, b0, c0, d0) (a1, b1, c1, d1) =
1539 compare a0 a1 &<& compare b0 b1 &<& compare c0 c1 &<& compare d0 d1
1541 instance (Additive a, Additive b, Additive c, Additive d) => Additive (a, b, c, d) where
1542 zero = (zero, zero, zero, zero)
1543 (a0, b0, c0, d0) + (a1, b1, c1, d1) = (a0+a1, b0+b1, c0+c1, d0+d1)
1545 instance Functor ((,,,) a b c) where
1546 fmap f (a,b,c,d) = (a, b, c, f d)
1548 instance (Show a, Show b, Show c, Show d) => Show (a, b, c, d) where
1549 sb <+ (x, y, z, w) = sb << "(" <+ x << ", " <+ y << ", " <+ z << ", " <+ w << ")"
1553 instance (Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e) where
1554 compare (a0, b0, c0, d0, e0) (a1, b1, c1, d1, e1) =
1555 compare a0 a1 &<& compare b0 b1 &<& compare c0 c1 &<& compare d0 d1 &<& compare e0 e1
1557 instance (Additive a, Additive b, Additive c, Additive d, Additive e) => Additive (a, b, c, d, e) where
1558 zero = (zero, zero, zero, zero, zero)
1559 (a0, b0, c0, d0, e0) + (a1, b1, c1, d1, e1) = (a0+a1, b0+b1, c0+c1, d0+d1, e0+e1)
1561 instance Functor ((,,,,) a b c d) where
1562 fmap f (a,b,c,d,e) = (a, b, c, d, f e)
1566 instance (Ord a) => Ord [a] where
1567 compare a b = loop 0
1572 then (if i >= lB then 0 else -1)
1575 else compare (a!i) (b!i) &<& loop (i+1)
1577 instance Functor [] where
1580 instance FunctorE [] where
1585 instance Monad [] where
1586 return x = singletonList x
1587 l >>= f = concatMap f l
1590 instance MonadZero [] where
1593 instance MonadPlus [] where
1596 instance Additive [a] where
1600 instance FunctorM [] where
1601 sequence = foldl (\m mel -> m >>= \l -> mel >>= \el -> return (addList l el)) (return emptyList)
1602 mapM f l = sequence (map f l)
1604 "Appends the string representations of all elements of the list to the string builder and separates the values with the given separator."
1605 printWithSeparator :: Show a => StringBuilder.T -> String -> [a] -> <Proc> StringBuilder.T
1606 printWithSeparator sb sep l = loop 0
1609 loop i = if i >= len then sb
1611 (if i==0 then sb else sb << sep) <+ l!i
1615 Joins the string representations of the list of values with the given separator.
1617 See [intercalate](#intercalate) for an alternative that works with Strings
1618 and doesn't escape its arguments.
1620 joinWithSeparator :: Show a => String -> [a] -> String
1621 joinWithSeparator separator values = runProc (
1622 StringBuilder.toString $ printWithSeparator StringBuilder.new separator values)
1626 The intercalate function takes a String and a list of Strings
1627 and concatenates the list after interspersing the first argument
1628 between each element of the list.
1630 See also more generic [joinWithSeparator](#joinWithSeparator)
1631 which escapes its arguments using `show`.
1633 intercalate :: String -> [String] -> String
1634 intercalate separator strings = do
1641 sb = StringBuilder.new
1643 loop i | i == l = ()
1645 sb << separator << strings!i
1648 StringBuilder.toString sb
1650 instance (Show a) => Show [a] where
1655 if (i>0) then sb << ", " else sb
1662 importJava "java.util.List" where
1663 "`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."
1665 getList :: [a] -> Integer -> a
1669 lengthList :: [a] -> Integer
1672 subList :: [a] -> Integer -> Integer -> [a]
1675 isEmpty :: [a] -> Boolean
1678 importJava "java.util.Collections" where
1680 //singletonList :: a -> [a]
1685 emptyList = build (\empty cons -> empty)
1688 "Creates a list with exectly one element."
1690 singletonList :: a -> [a]
1691 singletonList v = build (\empty cons -> cons empty v)
1694 // foldl f i (a + b) = foldl f (foldl f i a) b
1696 appendList :: [a] -> [a] -> [a]
1697 appendList a b = build (\empty cons -> foldl cons (foldl cons empty a) b)
1700 importJava "org.simantics.scl.runtime.list.ShareableList" where
1701 "Concatenates two lists."
1704 appendList :: [a] -> [a] -> [a]
1706 "Adds the given value to the end of the list."
1708 addList :: [a] -> a -> [a]
1711 importJava "java.util.ArrayList" where
1715 newArrayList :: <Proc> ArrayList a
1718 addArrayList :: ArrayList a -> a -> <Proc> ()
1721 A primitive for constructing a list by `empty` and `cons` operations given to the function given as a parameter to this function.
1724 build (\empty cons -> cons (cons (cons empty 1) 2) 3)
1730 The SCL compiler makes the following optimization when encountering `build` and `foldl` functions after inlining:
1732 foldl f i (build g) = g i f
1735 build :: forall b e2. (forall a e1. a -> (a -> b -> <e1> a) -> <e1,e2> a) -> <e2> [b]
1736 build f = runProc do
1738 f () (\_ v -> addArrayList l v)
1741 "A specific implementation of `map` for lists."
1744 mapEList :: (a -> <e> b) -> [a] -> <e> [b]
1745 mapEList f l = build (\empty cons -> foldl (\cur x -> cons cur (f x)) empty l)
1747 "A specific implementation of `fmap` for lists."
1749 mapList :: (a -> b) -> [a] -> [b]
1750 mapList f l = build (\empty cons -> foldl (\cur x -> cons cur (f x)) empty l)
1752 "`guardList v` returns a singleton `[()]` if `v=True` and the empty list if `v=False`."
1754 guardList :: Boolean -> [()]
1755 guardList cond = build (\empty cons -> if cond then cons empty () else empty)
1758 `concatMap` combines `map` and `join` functions.
1759 It maps the elements of a given list to lists with the given function and concatenates the results.
1761 concatMap f lst = join (map f lst) = [y | x <- lst, y <- f x]
1764 concatMap :: (a -> <e> [b]) -> [a] -> <e> [b]
1765 concatMap f l = build (\empty cons -> foldl (\cur le -> foldl cons cur (f le)) empty l)
1768 Applies the given function to the elements of the lists until the function returns something
1769 else than `Nothing`. This return value is also returned as a result of this function.
1772 mapFirst :: (a -> <e> Maybe b) -> [a] -> <e> Maybe b
1773 mapFirst f l = loop 0
1776 loop i = if i == len
1778 else match f (l!i) with
1780 Nothing -> loop (i+1)
1783 foldl op initialValue list
1785 applies a binary operator `op` to all elements of `list` from left to right
1786 starting with `initialValue`. For example,
1788 foldl op init [x1, x2, x3, x4] = (((init `op` x1) `op` x2) `op` x3) `op` x4
1791 foldl :: forall a b e. (a -> b -> <e> a) -> a -> [b] -> <e> a
1792 foldl f initial l = loop initial 0
1795 loop cur i = if i==len
1797 else loop (f cur (l!i)) (i+1)
1799 foldlI :: forall a b e. (Integer -> a -> b -> <e> a) -> a -> [b] -> <e> a
1800 foldlI f initial l = loop initial 0
1803 loop cur i = if i==len
1805 else loop (f i cur (l!i)) (i+1)
1807 scanl :: (b -> a -> <e> b) -> b -> [a] -> <e> [b]
1808 scanl f initial l = build (\empty cons -> let
1810 loop cur i accum = let nl = cons accum cur
1813 else loop (f cur (l!i)) (i+1) nl
1814 in loop initial 0 empty)
1816 "`foldr` is defined like `foldl` but it process the list from right to left."
1818 foldr :: (b -> a -> <e> a) -> a -> [b] -> <e> a
1819 foldr f initial l = loop initial (length l - 1)
1821 loop cur i = if i < 0
1823 else loop (f (l!i) cur) (i-1)
1825 foldr1 :: (a -> a -> <e> a) -> [a] -> <e> a
1826 foldr1 f l = loop (l!(len-1)) (len-2)
1829 loop cur i = if i < 0
1831 else loop (f (l!i) cur) (i-1)
1834 `filter pred lst` returns those elements of `lst` that the predicate `pred` accepts. For example
1836 filter (> 3) [1, 2, 3, 4, 5, 6] = [4, 5, 6]
1839 filter :: (a -> <e> Boolean) -> [a] -> <e> [a]
1840 filter p l = build (\empty cons -> foldl (\cur x -> if p x then cons cur x else cur) empty l)
1843 Takes those elements of the input list that match `(Just x)` and adds the contents to the resulting list. For example,
1845 filterJust [Just 1, Nothing, Just 5] = [1, 5]
1848 filterJust :: [Maybe a] -> [a]
1849 filterJust l = build (\empty cons -> foldl (\cur x -> match x with Just v -> cons cur v ; _ -> cur) empty l)
1851 listToMaybe :: [a] -> Maybe a
1852 listToMaybe l = if isEmpty l then Nothing else Just (l!0)
1854 maybeToList :: Maybe a -> [a]
1855 maybeToList (Just a) = [a]
1859 `takeWhile p l`, returns the longest prefix (possibly empty) of list `l` of elements that satisfy `p`
1861 takeWhile :: (a -> <e> Boolean) -> [a] -> <e> [a]
1862 takeWhile f l = loop 0
1865 loop i | i == len = l
1866 | f (l!i) = loop (i+1)
1867 | otherwise = take i l
1869 partition :: (a -> <e> Boolean) -> [a] -> <e> ([a], [a])
1870 partition p l = runProc do
1875 then addArrayList res1 el
1876 else addArrayList res2 el
1878 (Java.unsafeCoerce res1, Java.unsafeCoerce res2)
1881 `range begin end` produces a list of consecutive integers starting from `begin` and ending to `end` (including `end`).
1882 The compiler supports syntactic sugar `[begin..end]` for this function.
1885 range :: Integer -> Integer -> [Integer]
1886 range first last = build (\empty cons -> do
1887 loop i cur = if i > last then cur else loop (i+1) (cons cur i)
1890 "A specific implementation of `iter` for lists."
1892 iterList :: (a -> <e> b) -> [a] -> <e> ()
1893 iterList f l = foldl (\_ x -> ignore (f x)) () l
1895 "A specific implementation of `iterI` for lists."
1897 iterIList :: (Integer -> a -> <e> b) -> [a] -> <e> ()
1898 iterIList f l = do foldl (\i x -> do f i x ; i+1) 0 l ; ()
1901 Generates a list from a given starting state and iteration function.
1904 let nextState 0 = Nothing
1905 nextState i = Just (i, i `div` 2)
1906 in unfoldr nextState 30
1913 unfoldr :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1914 unfoldr f s = build (\empty cons -> do
1917 Just (el,newS) -> loop newS (cons cur el)
1921 importJava "org.simantics.scl.runtime.Lists" where
1925 mapList :: (a -> b) -> [a] -> [b]
1928 mapEList :: (a -> <e> b) -> [a] -> <e> [b]
1931 iterList :: (a -> <e> ()) -> [a] -> <e> ()
1932 concatMap :: (a -> <e> [b]) -> [a] -> <e> [b]
1935 Combines two lists into one list of pairs. The length of the resulting list is the length of the smallest input list.
1937 zip [1, 2, 3, 4, 5] ['a', 'b', 'c'] = [(1, 'a'), (2, 'b'), (3, 'c')]
1939 zip :: [a] -> [b] -> [(a,b)]
1940 "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."
1941 zipWith :: (a -> b -> <e> c) -> [a] -> [b] -> <e> [c]
1943 Produces two lists from one list of pairs.
1945 unzip [(1, 'a'), (2, 'b'), (3, 'c')] = ([1, 2, 3], ['a', 'b', 'c'])
1947 unzip :: [(a,b)] -> ([a],[b])
1949 //"@filter p l@ returns those elements of @l@ that the predicate @p@ accepts."
1950 //filter :: (a -> <e> Boolean) -> [a] -> <e> [a]
1951 //filterJust :: [Maybe a] -> [a]
1953 foldl :: (a -> b -> <e> a) -> a -> [b] -> <e> a
1955 "Like `foldl` but assumes that the list is non-empty so the initial is not needed."
1956 foldl1 :: (a -> a -> <e> a) -> [a] -> <e> a
1957 //unfoldr :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
1959 "Sorts the list using the given comparator."
1960 sortWith :: (a -> a -> <e> Integer) -> [a] -> <e> [a]
1963 Given a list of key-value pairs, the function produces a function that finds a value
1964 efficiently for the given key.
1966 index :: [(a,b)] -> a -> Maybe b
1969 Given a list of values and a function computing a key for each value, the function produces a function that finds a value
1970 effeciently for the given key.
1972 indexBy :: (a -> <e> b) -> [a] -> <e> (b -> Maybe a)
1974 "Works like `index` but uses the given functions as hash codes and equality."
1975 indexWith :: (a -> Integer) -> (a -> a -> Boolean) -> [(a,b)] -> a -> Maybe b
1977 "Groups a list values by a key computed by the given function."
1978 groupBy :: (a -> <e> b) -> [a] -> <e> [(b, [a])]
1980 "Groups a list of key-value pairs by the keys."
1981 group :: [(a,b)] -> [(a, [b])]
1983 "Composition of index and groupBy."
1984 indexGroupBy :: (a -> <e> b) -> [a] -> <e> (b -> [a])
1986 "Composition of index and group."
1987 indexGroup :: [(a,b)] -> a -> [b]
1989 groupWith :: (b -> Integer) -> (b -> b -> Boolean) -> (a -> <e> b) -> (a -> <e> c) -> [a] -> <e> [(b, [c])]
1991 "Removes duplicates (all but the first occurrence) from the list but otherwise preserves the order of the elements."
1992 unique :: [a] -> [a]
1994 "Like `unique`, but uses the given function for finding the key values used for uniqueness testing."
1995 uniqueBy :: (a -> b) -> [a] -> [a]
1997 "Works like `unique` but uses the given function for equality tests."
1998 uniqueWith :: (a -> a -> Boolean) -> [a] -> [a]
2000 "Works like `\\\\` but uses the given function for equality tests."
2001 deleteAllBy :: (a -> a -> Boolean) -> [a] -> [a] -> [a]
2004 listDifference :: [a] -> [a] -> [a]
2006 //range :: Integer -> Integer -> [Integer]
2008 //build :: (forall a. a -> (a -> b -> <e> a) -> <e> a) -> <e> [b]
2010 "`elem el lst` return true, if `el` occurs in the list `lst`."
2011 elem :: a -> [a] -> Boolean
2015 loop i | i < len = if el == l!i
2020 "`elemMaybe v1 (Just v2)` returns true if `v1 == v2`. `elemMaybe v1 Nothing` is always false."
2021 elemMaybe :: a -> Maybe a -> Boolean
2022 elemMaybe el m = match m with
2023 Just el2 -> el == el2
2026 "`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."
2027 elemIndex :: a -> [a] -> Maybe Integer
2028 elemIndex el l = loop 0
2031 loop i | i < len = if el == l!i
2034 | otherwise = Nothing
2037 Computes a list that contains only elements that belongs to both input lists.
2039 intersect :: [a] -> [a] -> [a]
2040 intersect a b = filter f a
2044 "Reverses a given list. For example, `reverse [1,2,3] = [3,2,1]`"
2045 reverse :: [a] -> [a]
2046 reverse l = [l!(len-i) | i <- [1..len]]
2051 Transposes the rows and columns of its argument. For example,
2053 transpose [[1,2,3],[4,5,6]] == [[1,4],[2,5],[3,6]]
2054 transpose [[1,2],[3,4,5]] == [[1,3],[2,4],[5]]
2056 transpose xss = [[xs!i | xs <- xss, i < length xs]
2057 | i <- [0..maximum [length xs | xs <- xss]-1]]
2059 "Works like `unfoldr` but generates the list from right to left."
2060 unfoldl :: (b -> <e> Maybe (a, b)) -> b -> <e> [a]
2061 unfoldl f seed = reverse $ unfoldr f seed
2063 "Removes the first element of the list, if the list is non-empty."
2065 tail l = if len < 2 then emptyList else subList l 1 len
2069 "Tries to find the given key from the list of key-value pairs and returns the corresponding value."
2070 lookup :: a -> [(a, b)] -> Maybe b
2075 (a,b) | a == el -> Just b
2076 | otherwise -> loop (i+1)
2080 "Conjunction over a list."
2082 and :: [Boolean] -> Boolean
2083 and = foldl (&&) True
2085 "Disjunction over a list."
2087 or :: [Boolean] -> Boolean
2088 or = foldl (||) False
2091 `any pred lst` tests whether the predicate `pred` holds some element of `lst`.
2092 It returns immediately when it encounters the first value satisfying the predicate.
2094 any :: (a -> <e> Boolean) -> [a] -> <e> Boolean
2098 `all pred lst` tests whether the predicate `pred` holds for all elements of `lst`.
2099 It returns immediately when it encounters the first value not satisfying the predicate.
2101 all :: (a -> <e> Boolean) -> [a] -> <e> Boolean
2105 Returns the first element of the list satisfying the given condition,
2106 or `Nothing` if there is no such element.
2108 findFirst :: (a -> <e> Boolean) -> [a] -> <e> Maybe a
2109 findFirst p l = loop 0
2113 then let el = l!i in
2122 Sorts the given list using its default order.
2125 sort :: Ord a => [a] -> [a]
2126 sort = sortWith compare
2129 Sorts the lists by the values computed by the first function.
2132 sortBy snd [(1,5), (2,3), (3,4)] = [(2,3), (3,4), (1,5)]
2135 sortBy :: Ord b => (a -> <e> b) -> [a] -> <e> [a]
2136 sortBy f l = sortWith (\x y -> compare (f x) (f y)) l
2137 // This is faster if f is slow, but will generate more auxiliary structures
2138 //sortBy f l = map snd (sortWith (\(x,_) (y,_) -> compare x y) [(f x, x) | x <- l])
2140 "`a \\\\ b` removes all elements of `b` from the list `a`."
2141 (\\) :: [a] -> [a] -> [a]
2142 (\\) = listDifference
2146 importJava "java.lang.Object" where
2147 "A data type that can represent any value."
2152 showDynamic :: Dynamic -> String
2154 instance Show Dynamic where
2157 "Converts a value to `Dynamic` type."
2158 toDynamic :: a -> Dynamic
2159 toDynamic = Java.unsafeCoerce
2161 "Converts a `Dynamic` value to a required value, or fails if the conversion is not possible."
2162 importJava "org.simantics.scl.compiler.runtime.ValueConversion" where
2163 fromDynamic :: Typeable a => Dynamic -> a
2167 importJava "org.simantics.scl.runtime.procedure.Ref" where
2168 "A mutable reference to a value of type `a`."
2171 "Creates a new reference with the given initial value."
2173 ref :: a -> <Proc> (Ref a)
2175 "Returns the current value of the reference."
2177 getRef :: Ref a -> <Proc> a
2179 "Sets a new value for the reference."
2180 @JavaName "<set>value"
2181 (:=) :: Ref a -> a -> <Proc> ()
2183 instance Show (Ref a) where
2184 show _ = "<reference>"
2186 importJava "org.simantics.scl.runtime.reporting.SCLReporting" where
2187 "Prints the given string to the console."
2189 printString :: String -> <Proc> ()
2190 "Prints an error message to the console."
2191 printError :: String -> <Proc> ()
2192 "Reports that certain amount of work has been done for the current task."
2193 didWork :: Double -> <Proc> ()
2195 `printingToFile "fileName" expression` executes the `expression` so that all its console prints
2196 are written to the file given as a first parameter.
2198 printingToFile :: String -> (<e> a) -> <e> a
2200 `printErrorsAsNormalPrints expression` executes the `expression` so that all its error prints
2201 are printed as normal prints. This is useful mainly in testing scripts for checking that the implementations
2202 give proper error messages with invalid inputs.
2204 printErrorsAsNormalPrints :: (<e> a) -> <e> a
2206 `disablePrintingForCommand expression` executes the `expression` so that it does not print return values.
2207 Errors are printed normally.
2209 disablePrintingForCommand :: (<e> a) -> <e> a
2212 importJava "org.simantics.scl.runtime.procedure.Procedures" where
2213 "Returns `True` if the current thread has been interrupted."
2214 isInterrupted :: <Proc> Boolean
2215 "Checks whether the current thread has been interrupted and throws an exception if it is."
2216 checkInterrupted :: <Proc> ()
2217 "Generates a random identifier."
2218 generateUID :: <Proc> String
2220 "Executes the given expression and catches certain class of exceptions (specified by the catch handler that is given as a second parameter.)"
2222 catch :: VecComp ex => (<e,Exception> a) -> (ex -> <e> a) -> <e> a
2224 importJava "java.lang.Throwable" where
2228 showThrowable :: Throwable -> String
2230 @JavaName getMessage
2231 getMessageThrowable :: Throwable -> String
2234 getCauseThrowable :: Throwable -> Maybe Throwable
2235 importJava "java.lang.Exception" where
2239 showException :: Exception -> String
2241 instance Show Throwable where
2242 show = showThrowable
2243 instance Show Exception where
2244 show = showException
2246 class Throwable e where
2247 toThrowable :: e -> Throwable
2249 messageOfException :: Throwable e => e -> String
2250 messageOfException = getMessageThrowable . toThrowable
2252 causeOfException :: Throwable e => e -> Maybe Throwable
2253 causeOfException = getCauseThrowable . toThrowable
2255 instance Throwable Throwable where
2257 instance Throwable Exception where
2258 toThrowable = Java.unsafeCoerce
2260 "Prints the given value in the console."
2262 print :: Show a => a -> <Proc> ()
2263 print v = printString (showForPrinting v)
2265 instance Show TypeRep where
2266 sb <+ (TApply (TCon "Builtin" "[]") b) =
2267 sb << "[" <+ b << "]"
2268 sb <+ (TApply (TApply (TCon "Builtin" "(,)") c1) c2) =
2269 sb << "(" <+ c1 << "," <+ c2 << ")"
2270 sb <+ (TApply (TApply (TApply (TCon "Builtin" "(,,)") c1) c2) c3) =
2271 sb << "(" <+ c1 << "," <+ c2 << "," <+ c3 << ")"
2272 sb <+ (TApply (TApply (TApply (TApply (TCon "Builtin" "(,,,)") c1) c2) c3) c4) =
2273 sb << "(" <+ c1 << "," <+ c2 << "," <+ c3 << "," <+ c4 << ")"
2275 sb <+ (TCon _ name) = sb << name
2276 sb <+ (TApply a b) = sb <+ Par 1 a << " " <+ Par 2 b
2277 sb <+ (TFun a b) = sb <+ Par 1 a << " -> " <+ b
2279 precedence (TCon _ _) = 0
2280 precedence (TFun _ _) = 2
2281 precedence (TApply a _) = if isSpecialType a then 0 else 1
2283 isSpecialType (TCon "Builtin" "[]") = True
2284 isSpecialType (TCon "Builtin" "()") = True
2285 isSpecialType (TCon "Builtin" "(,)") = True
2286 isSpecialType (TCon "Builtin" "(,,)") = True
2287 isSpecialType (TCon "Builtin" "(,,,)") = True
2288 isSpecialType (TApply a _) = isSpecialType a
2294 importJava "org.simantics.scl.compiler.types.Type" where
2296 showType :: Type -> String
2298 importJava "org.simantics.scl.compiler.types.Types" where
2299 removeForAll :: Type -> Type
2301 instance Show Type where