--- /dev/null
+definition module Random
+
+ // Random number generator voor Linux gebruikers
+ // interface compatible met Random.dcl (helaas)
+ // -- mschool@science.ru.nl
+
+import StdFile
+
+:: RandomSeed
+
+// nullRandomSeed generates a fixed RandomSeed
+nullRandomSeed :: RandomSeed
+
+// GetNewRandomSeed generates a good RandomSeed, using /dev/urandom
+getNewRandomSeed :: !*env -> (!RandomSeed, !*env) | FileSystem env
+
+// Given a RandomSeed, Random generates a random number and a new RandomSeed.
+random :: !RandomSeed -> .(!Int, !RandomSeed)
+
--- /dev/null
+implementation module Random
+
+import StdFile, StdList, StdMisc, StdArray, Random
+
+:: RandomSeed :== Int
+
+nullRandomSeed :: RandomSeed
+nullRandomSeed = 0
+
+getNewRandomSeed :: !*env -> (!RandomSeed, !*env) | FileSystem env
+getNewRandomSeed env
+# (ok, src, env) = sfopen "/dev/urandom" FReadData env
+| not ok => abort "could not open /dev/urandom"
+# (bytes, src) = sfreads src 4
+ seed = foldl (\x y->(x<<8)+toInt y) 0 [c \\ c<-:bytes]
+| otherwise => (seed, env)
+
+random :: !RandomSeed -> .(!Int, !RandomSeed)
+random seed = (seed>>16 bitand 0xFFFF, seed*0x08088405+1)
+
--- /dev/null
+definition module StdMaybe
+
+// ********************************************************************************
+// Clean StdLib library module, version 1.0
+// ********************************************************************************
+
+from StdFunc import :: St;
+from StdOverloaded import class ==(..);
+
+:: Maybe x
+ = Just x
+ | Nothing
+
+isJust :: !(Maybe .x) -> Bool // case @1 of (Just _) -> True; _ -> False
+isNothing :: !(Maybe .x) -> Bool // not o isJust
+fromJust :: !(Maybe .x) -> .x // \(Just x) -> x
+
+// for possibly unique elements:
+u_isJust :: !u:(Maybe .x) -> (!Bool, !u:Maybe .x)
+u_isNothing :: !u:(Maybe .x) -> (!Bool, !u:Maybe .x)
+
+accMaybe :: .(St .x .a) !u:(Maybe .x) -> (!Maybe .a,!u:Maybe .x)
+// accMaybe f (Just x) = (Just (fst (f x)),Just (snd (f x)))
+// accMaybe f Nothing = (Nothing,Nothing)
+
+mapMaybe :: .(.x -> .y) !(Maybe .x) -> Maybe .y
+// mapMaybe f (Just x) = Just (f x)
+// mapMaybe f Nothing = Nothing
+
+instance == (Maybe x) | == x
+// Nothing==Nothing
+// Just a ==Just b <= a==b
+
+maybeToList :: !(Maybe .a) -> [.a];
+// returns list with no or one element
+
+listToMaybe :: ![.a] -> .Maybe .a;
+// returns Just head of list if possible
+
+catMaybes :: ![Maybe .a] -> .[.a];
+// catMaybes ms = [ m \\ Just m <- ms ]
--- /dev/null
+implementation module StdMaybe
+
+// ********************************************************************************
+// Clean StdLib library module, version 1.0
+// ********************************************************************************
+
+from StdFunc import :: St;
+from StdOverloaded import class ==(..);
+
+:: Maybe x
+ = Just x
+ | Nothing
+
+isJust :: !(Maybe .x) -> Bool
+isJust Nothing = False
+isJust _ = True
+
+isNothing :: !(Maybe .x) -> Bool
+isNothing Nothing = True
+isNothing _ = False
+
+u_isJust :: !u:(Maybe .x) -> (!Bool, !u:Maybe .x)
+u_isJust nothing=:Nothing
+ = (False, nothing)
+u_isJust just
+ = (True, just)
+
+u_isNothing :: !u:(Maybe .x) -> (!Bool, !u:Maybe .x)
+u_isNothing nothing=:Nothing
+ = (True, nothing)
+u_isNothing just
+ = (False,just)
+
+fromJust :: !(Maybe .x) -> .x
+fromJust (Just x) = x
+
+accMaybe :: .(St .x .a) !u:(Maybe .x) -> (!Maybe .a,!u:Maybe .x)
+accMaybe f (Just x)
+ # (a,x) = f x
+ = (Just a,Just x)
+accMaybe _ nothing
+ = (Nothing,nothing)
+
+mapMaybe :: .(.x -> .y) !(Maybe .x) -> Maybe .y
+mapMaybe f (Just x) = Just (f x)
+mapMaybe _ nothing = Nothing
+
+instance == (Maybe x) | == x where
+ (==) Nothing maybe = case maybe of
+ Nothing -> True
+ just -> False
+ (==) (Just a) maybe = case maybe of
+ Just b -> a==b
+ nothing -> False
+
+maybeToList :: !(Maybe .a) -> [.a];
+maybeToList Nothing = []
+maybeToList (Just a) = [a]
+
+listToMaybe :: ![.a] -> .Maybe .a;
+listToMaybe [] = Nothing
+listToMaybe [a:_] = Just a
+
+catMaybes :: ![Maybe .a] -> .[.a];
+catMaybes ms = [ m \\ Just m <- ms ]