gf-3.6: src/compiler/GF/Data/Operations.hs
----------------------------------------------------------------------
-- |
-- Module : Operations
-- Maintainer : AR
-- Stability : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 2005/11/11 16:12:41 $
-- > CVS $Author: bringert $
-- > CVS $Revision: 1.22 $
--
-- some auxiliary GF operations. AR 19\/6\/1998 -- 6\/2\/2001
--
-- Copyright (c) Aarne Ranta 1998-2000, under GNU General Public License (see GPL)
-----------------------------------------------------------------------------
module GF.Data.Operations (-- * misc functions
ifNull,
-- * the Error monad
Err(..), err, maybeErr, testErr, errVal, errIn,
lookupErr,
mapPairListM, mapPairsM, pairM,
singleton, --mapsErr, mapsErrTree,
-- ** checking
checkUnique, unifyMaybeBy, unifyMaybe,
-- * binary search trees; now with FiniteMap
BinTree, emptyBinTree, isInBinTree, justLookupTree,
lookupTree, --lookupTreeMany,
lookupTreeManyAll, updateTree,
buildTree, filterBinTree,
--sorted2tree,
mapTree, --mapMTree,
tree2list,
-- * printing
indent, (+++), (++-), (++++), (+++++),
prUpper, prReplicate, prTList, prQuotedString, prParenth, prCurly,
prBracket, prArgList, prSemicList, prCurlyList, restoreEscapes,
numberedParagraphs, prConjList, prIfEmpty, wrapLines,
-- * extra
combinations,
-- * topological sorting with test of cyclicity
topoTest, topoTest2,
-- * the generic fix point iterator
iterFix,
-- * chop into separator-separated parts
chunks, readIntArg,
-- * state monad with error; from Agda 6\/11\/2001
STM(..), appSTM, stm, stmr, readSTM, updateSTM, writeSTM, done,
-- * error monad class
ErrorMonad(..), checkAgain, checks, allChecks, doUntil,
liftErr
) where
import Data.Char (isSpace, toUpper, isSpace, isDigit)
import Data.List (nub, partition, (\\))
import qualified Data.Map as Map
import Data.Map (Map)
import Control.Monad (liftM,liftM2)
import GF.Data.ErrM
import GF.Data.Relation
infixr 5 +++
infixr 5 ++-
infixr 5 ++++
infixr 5 +++++
ifNull :: b -> ([a] -> b) -> [a] -> b
ifNull b f xs = if null xs then b else f xs
-- the Error monad
-- | analogue of @maybe@
err :: (String -> b) -> (a -> b) -> Err a -> b
err d f e = case e of
Ok a -> f a
Bad s -> d s
-- | add msg s to @Maybe@ failures
maybeErr :: ErrorMonad m => String -> Maybe a -> m a
maybeErr s = maybe (raise s) return
testErr :: ErrorMonad m => Bool -> String -> m ()
testErr cond msg = if cond then return () else raise msg
errVal :: a -> Err a -> a
errVal a = err (const a) id
errIn :: ErrorMonad m => String -> m a -> m a
errIn msg m = handle m (\s -> raise (s ++++ "OCCURRED IN" ++++ msg))
lookupErr :: (ErrorMonad m,Eq a,Show a) => a -> [(a,b)] -> m b
lookupErr a abs = maybeErr ("Unknown" +++ show a) (lookup a abs)
mapPairListM :: Monad m => ((a,b) -> m c) -> [(a,b)] -> m [(a,c)]
mapPairListM f xys = mapM (\ p@(x,_) -> liftM ((,) x) (f p)) xys
mapPairsM :: Monad m => (b -> m c) -> [(a,b)] -> m [(a,c)]
mapPairsM f xys = mapM (\ (x,y) -> liftM ((,) x) (f y)) xys
pairM :: Monad a => (b -> a c) -> (b,b) -> a (c,c)
pairM op (t1,t2) = liftM2 (,) (op t1) (op t2)
singleton :: a -> [a]
singleton = (:[])
-- checking
checkUnique :: (Show a, Eq a) => [a] -> [String]
checkUnique ss = ["overloaded" +++ show s | s <- nub overloads] where
overloads = filter overloaded ss
overloaded s = length (filter (==s) ss) > 1
-- | this is what happens when matching two values in the same module
unifyMaybe :: (Eq a, Monad m) => Maybe a -> Maybe a -> m (Maybe a)
unifyMaybe = unifyMaybeBy id
unifyMaybeBy :: (Eq b, Monad m) => (a->b) -> Maybe a -> Maybe a -> m (Maybe a)
unifyMaybeBy f (Just p1) (Just p2)
| f p1==f p2 = return (Just p1)
| otherwise = fail ""
unifyMaybeBy _ Nothing mp2 = return mp2
unifyMaybeBy _ mp1 _ = return mp1
-- binary search trees
type BinTree a b = Map a b
emptyBinTree :: BinTree a b
emptyBinTree = Map.empty
isInBinTree :: (Ord a) => a -> BinTree a b -> Bool
isInBinTree = Map.member
justLookupTree :: (Monad m,Ord a) => a -> BinTree a b -> m b
justLookupTree = lookupTree (const [])
lookupTree :: (Monad m,Ord a) => (a -> String) -> a -> BinTree a b -> m b
lookupTree pr x tree = case Map.lookup x tree of
Just y -> return y
_ -> fail ("no occurrence of element" +++ pr x)
{-
lookupTreeMany :: Ord a => (a -> String) -> [BinTree a b] -> a -> Err b
lookupTreeMany pr (t:ts) x = case lookupTree pr x t of
Ok v -> return v
_ -> lookupTreeMany pr ts x
lookupTreeMany pr [] x = Bad $ "failed to find" +++ pr x
-}
lookupTreeManyAll :: Ord a => (a -> String) -> [BinTree a b] -> a -> [b]
lookupTreeManyAll pr (t:ts) x = case lookupTree pr x t of
Ok v -> v : lookupTreeManyAll pr ts x
_ -> lookupTreeManyAll pr ts x
lookupTreeManyAll pr [] x = []
updateTree :: (Ord a) => (a,b) -> BinTree a b -> BinTree a b
updateTree (a,b) = Map.insert a b
buildTree :: (Ord a) => [(a,b)] -> BinTree a b
buildTree = Map.fromList
{-
sorted2tree :: Ord a => [(a,b)] -> BinTree a b
sorted2tree = Map.fromAscList
-}
mapTree :: ((a,b) -> c) -> BinTree a b -> BinTree a c
mapTree f = Map.mapWithKey (\k v -> f (k,v))
{-
mapMTree :: (Ord a,Monad m) => ((a,b) -> m c) -> BinTree a b -> m (BinTree a c)
mapMTree f t = liftM Map.fromList $ sequence [liftM ((,) k) (f (k,x)) | (k,x) <- Map.toList t]
-}
filterBinTree :: Ord a => (a -> b -> Bool) -> BinTree a b -> BinTree a b
filterBinTree = Map.filterWithKey
tree2list :: BinTree a b -> [(a,b)] -- inorder
tree2list = Map.toList
-- printing
indent :: Int -> String -> String
indent i s = replicate i ' ' ++ s
(+++), (++-), (++++), (+++++) :: String -> String -> String
a +++ b = a ++ " " ++ b
a ++- "" = a
a ++- b = a +++ b
a ++++ b = a ++ "\n" ++ b
a +++++ b = a ++ "\n\n" ++ b
prUpper :: String -> String
prUpper s = s1 ++ s2' where
(s1,s2) = span isSpace s
s2' = case s2 of
c:t -> toUpper c : t
_ -> s2
prReplicate :: Int -> String -> String
prReplicate n s = concat (replicate n s)
prTList :: String -> [String] -> String
prTList t ss = case ss of
[] -> ""
[s] -> s
s:ss -> s ++ t ++ prTList t ss
prQuotedString :: String -> String
prQuotedString x = "\"" ++ restoreEscapes x ++ "\""
prParenth :: String -> String
prParenth s = if s == "" then "" else "(" ++ s ++ ")"
prCurly, prBracket :: String -> String
prCurly s = "{" ++ s ++ "}"
prBracket s = "[" ++ s ++ "]"
prArgList, prSemicList, prCurlyList :: [String] -> String
prArgList = prParenth . prTList ","
prSemicList = prTList " ; "
prCurlyList = prCurly . prSemicList
restoreEscapes :: String -> String
restoreEscapes s =
case s of
[] -> []
'"' : t -> '\\' : '"' : restoreEscapes t
'\\': t -> '\\' : '\\' : restoreEscapes t
c : t -> c : restoreEscapes t
numberedParagraphs :: [[String]] -> [String]
numberedParagraphs t = case t of
[] -> []
p:[] -> p
_ -> concat [(show n ++ ".") : s | (n,s) <- zip [1..] t]
prConjList :: String -> [String] -> String
prConjList c [] = ""
prConjList c [s] = s
prConjList c [s,t] = s +++ c +++ t
prConjList c (s:tt) = s ++ "," +++ prConjList c tt
prIfEmpty :: String -> String -> String -> String -> String
prIfEmpty em _ _ [] = em
prIfEmpty em nem1 nem2 s = nem1 ++ s ++ nem2
-- | Thomas Hallgren's wrap lines
wrapLines :: Int -> String -> String
wrapLines n "" = ""
wrapLines n s@(c:cs) =
if isSpace c
then c:wrapLines (n+1) cs
else case lex s of
[(w,rest)] -> if n'>=76
then '\n':w++wrapLines l rest
else w++wrapLines n' rest
where n' = n+l
l = length w
_ -> s -- give up!!
--- optWrapLines = if argFlag "wraplines" True then wrapLines 0 else id
-- | 'combinations' is the same as @sequence@!!!
-- peb 30\/5-04
combinations :: [[a]] -> [[a]]
combinations t = case t of
[] -> [[]]
aa:uu -> [a:u | a <- aa, u <- combinations uu]
-- | topological sorting with test of cyclicity
topoTest :: Ord a => [(a,[a])] -> Either [a] [[a]]
topoTest = topologicalSort . mkRel'
-- | topological sorting with test of cyclicity, new version /TH 2012-06-26
topoTest2 :: Ord a => [(a,[a])] -> Either [[a]] [[a]]
topoTest2 g0 = maybe (Right cycles) Left (tsort g)
where
g = g0++[(n,[])|n<-nub (concatMap snd g0)\\map fst g0]
cycles = findCycles (mkRel' g)
tsort nes =
case partition (null.snd) nes of
([],[]) -> Just []
([],_) -> Nothing
(ns,rest) -> (leaves:) `fmap` tsort [(n,es \\ leaves) | (n,es)<-rest]
where leaves = map fst ns
-- | the generic fix point iterator
iterFix :: Eq a => ([a] -> [a]) -> [a] -> [a]
iterFix more start = iter start start
where
iter old new = if (null new')
then old
else iter (new' ++ old) new'
where
new' = filter (`notElem` old) (more new)
-- | chop into separator-separated parts
chunks :: Eq a => a -> [a] -> [[a]]
chunks sep ws = case span (/= sep) ws of
(a,_:b) -> a : bs where bs = chunks sep b
(a, []) -> if null a then [] else [a]
readIntArg :: String -> Int
readIntArg n = if (not (null n) && all isDigit n) then read n else 0
-- state monad with error; from Agda 6/11/2001
newtype STM s a = STM (s -> Err (a,s))
appSTM :: STM s a -> s -> Err (a,s)
appSTM (STM f) s = f s
stm :: (s -> Err (a,s)) -> STM s a
stm = STM
stmr :: (s -> (a,s)) -> STM s a
stmr f = stm (\s -> return (f s))
instance Functor (STM s) where fmap = liftM
instance Monad (STM s) where
return a = STM (\s -> return (a,s))
STM c >>= f = STM (\s -> do
(x,s') <- c s
let STM f' = f x
f' s')
readSTM :: STM s s
readSTM = stmr (\s -> (s,s))
updateSTM :: (s -> s) -> STM s ()
updateSTM f = stmr (\s -> ((),f s))
writeSTM :: s -> STM s ()
writeSTM s = stmr (const ((),s))
done :: Monad m => m ()
done = return ()
class (Functor m,Monad m) => ErrorMonad m where
raise :: String -> m a
handle :: m a -> (String -> m a) -> m a
handle_ :: m a -> m a -> m a
handle_ a b = a `handle` (\_ -> b)
instance ErrorMonad Err where
raise = Bad
handle a@(Ok _) _ = a
handle (Bad i) f = f i
liftErr e = err raise return e
instance ErrorMonad (STM s) where
raise msg = STM (\s -> raise msg)
handle (STM f) g = STM (\s -> (f s)
`handle` (\e -> let STM g' = (g e) in
g' s))
{-
-- error recovery with multiple reporting AR 30/5/2008
mapsErr :: (a -> Err b) -> [a] -> Err [b]
mapsErr f = seqs . map f where
seqs es = case es of
Ok v : ms -> case seqs ms of
Ok vs -> return (v : vs)
b -> b
Bad s : ms -> case seqs ms of
Ok vs -> Bad s
Bad ss -> Bad (s +++++ ss)
[] -> return []
mapsErrTree :: (Ord a) => ((a,b) -> Err (a,c)) -> BinTree a b -> Err (BinTree a c)
mapsErrTree f t = mapsErr f (tree2list t) >>= return . sorted2tree
-}
-- | if the first check fails try another one
checkAgain :: ErrorMonad m => m a -> m a -> m a
checkAgain c1 c2 = handle_ c1 c2
checks :: ErrorMonad m => [m a] -> m a
checks [] = raise "no chance to pass"
checks cs = foldr1 checkAgain cs
allChecks :: ErrorMonad m => [m a] -> m [a]
allChecks ms = case ms of
(m: ms) -> let rs = allChecks ms in handle_ (liftM2 (:) m rs) rs
_ -> return []
doUntil :: ErrorMonad m => (a -> Bool) -> [m a] -> m a
doUntil cond ms = case ms of
a:as -> do
v <- a
if cond v then return v else doUntil cond as
_ -> raise "no result"