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| author | aarne <aarne@cs.chalmers.se> | 2008-06-25 16:54:35 +0000 |
|---|---|---|
| committer | aarne <aarne@cs.chalmers.se> | 2008-06-25 16:54:35 +0000 |
| commit | e9e80fc389365e24d4300d7d5390c7d833a96c50 (patch) | |
| tree | f0b58473adaa670bd8fc52ada419d8cad470ee03 /src/GF/Compile/GFCCtoHaskell.hs | |
| parent | b96b36f43de3e2f8b58d5f539daa6f6d47f25870 (diff) | |
changed names of resource-1.3; added a note on homepage on release
Diffstat (limited to 'src/GF/Compile/GFCCtoHaskell.hs')
| -rw-r--r-- | src/GF/Compile/GFCCtoHaskell.hs | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/GF/Compile/GFCCtoHaskell.hs b/src/GF/Compile/GFCCtoHaskell.hs new file mode 100644 index 000000000..59db9c364 --- /dev/null +++ b/src/GF/Compile/GFCCtoHaskell.hs @@ -0,0 +1,213 @@ +---------------------------------------------------------------------- +-- | +-- Module : GFCCtoHaskell +-- Maintainer : Aarne Ranta +-- Stability : (stable) +-- Portability : (portable) +-- +-- > CVS $Date: 2005/06/17 12:39:07 $ +-- > CVS $Author: bringert $ +-- > CVS $Revision: 1.8 $ +-- +-- to write a GF abstract grammar into a Haskell module with translations from +-- data objects into GF trees. Example: GSyntax for Agda. +-- AR 11/11/1999 -- 7/12/2000 -- 18/5/2004 +----------------------------------------------------------------------------- + +module GF.Compile.GFCCtoHaskell (grammar2haskell, grammar2haskellGADT) where + +import PGF.CId +import PGF.Data +import PGF.Macros + +import GF.Data.Operations +import GF.Text.UTF8 + +import Data.List --(isPrefixOf, find, intersperse) +import qualified Data.Map as Map + +-- | the main function +grammar2haskell :: String -- ^ Module name. + -> PGF + -> String +grammar2haskell name gr = encodeUTF8 $ foldr (++++) [] $ + haskPreamble name ++ [datatypes gr', gfinstances gr'] + where gr' = hSkeleton gr + +grammar2haskellGADT :: String -> PGF -> String +grammar2haskellGADT name gr = encodeUTF8 $ foldr (++++) [] $ + ["{-# OPTIONS_GHC -fglasgow-exts #-}"] ++ + haskPreamble name ++ [datatypesGADT gr', gfinstances gr'] + where gr' = hSkeleton gr + +-- | by this you can prefix all identifiers with stg; the default is 'G' +gId :: OIdent -> OIdent +gId i = 'G':i + +haskPreamble name = + [ + "module " ++ name ++ " where", + "", + "import PGF", + "----------------------------------------------------", + "-- automatic translation from GF to Haskell", + "----------------------------------------------------", + "", + "class Gf a where", + " gf :: a -> Tree", + " fg :: Tree -> a", + "", + predefInst "GString" "String" "Lit (LStr s)", + "", + predefInst "GInt" "Integer" "Lit (LInt s)", + "", + predefInst "GFloat" "Double" "Lit (LFlt s)", + "", + "----------------------------------------------------", + "-- below this line machine-generated", + "----------------------------------------------------", + "" + ] + +predefInst gtyp typ patt = + "newtype" +++ gtyp +++ "=" +++ gtyp +++ typ +++ " deriving Show" +++++ + "instance Gf" +++ gtyp +++ "where" ++++ + " gf (" ++ gtyp +++ "s) =" +++ patt ++++ + " fg t =" ++++ + " case t of" ++++ + " " +++ patt +++ " ->" +++ gtyp +++ "s" ++++ + " _ -> error (\"no" +++ gtyp +++ "\" ++ show t)" + +type OIdent = String + +type HSkeleton = [(OIdent, [(OIdent, [OIdent])])] + +datatypes, gfinstances :: (String,HSkeleton) -> String +datatypes = (foldr (+++++) "") . (filter (/="")) . (map hDatatype) . snd +gfinstances (m,g) = (foldr (+++++) "") $ (filter (/="")) $ (map (gfInstance m)) g + +hDatatype :: (OIdent, [(OIdent, [OIdent])]) -> String +gfInstance :: String -> (OIdent, [(OIdent, [OIdent])]) -> String + +hDatatype ("Cn",_) = "" --- +hDatatype (cat,[]) = "" +hDatatype (cat,rules) | isListCat (cat,rules) = + "newtype" +++ gId cat +++ "=" +++ gId cat +++ "[" ++ gId (elemCat cat) ++ "]" + +++ "deriving Show" +hDatatype (cat,rules) = + "data" +++ gId cat +++ "=" ++ + (if length rules == 1 then "" else "\n ") +++ + foldr1 (\x y -> x ++ "\n |" +++ y) + [gId f +++ foldr (+++) "" (map gId xx) | (f,xx) <- rules] ++++ + " deriving Show" + +-- GADT version of data types +datatypesGADT :: (String,HSkeleton) -> String +datatypesGADT (_,skel) = + unlines (concatMap hCatTypeGADT skel) + +++++ + "data Tree :: * -> * where" ++++ unlines (concatMap (map (" "++) . hDatatypeGADT) skel) + +hCatTypeGADT :: (OIdent, [(OIdent, [OIdent])]) -> [String] +hCatTypeGADT (cat,rules) + = ["type"+++gId cat+++"="+++"Tree"+++gId cat++"_", + "data"+++gId cat++"_"] + +hDatatypeGADT :: (OIdent, [(OIdent, [OIdent])]) -> [String] +hDatatypeGADT (cat, rules) + | isListCat (cat,rules) = [gId cat+++"::"+++"["++gId (elemCat cat)++"]" +++ "->" +++ t] + | otherwise = + [ gId f +++ "::" +++ concatMap (\a -> gId a +++ "-> ") args ++ t | (f,args) <- rules ] + where t = "Tree" +++ gId cat ++ "_" + +gfInstance m crs = hInstance m crs ++++ fInstance m crs + +----hInstance m ("Cn",_) = "" --- seems to belong to an old applic. AR 18/5/2004 +hInstance m (cat,[]) = "" +hInstance m (cat,rules) + | isListCat (cat,rules) = + "instance Gf" +++ gId cat +++ "where" ++++ + " gf (" ++ gId cat +++ "[" ++ concat (intersperse "," baseVars) ++ "])" + +++ "=" +++ mkRHS ("Base"++ec) baseVars ++++ + " gf (" ++ gId cat +++ "(x:xs)) = " + ++ mkRHS ("Cons"++ec) ["x",prParenth (gId cat+++"xs")] +-- no show for GADTs +-- ++++ " gf (" ++ gId cat +++ "xs) = error (\"Bad " ++ cat ++ " value: \" ++ show xs)" + | otherwise = + "instance Gf" +++ gId cat +++ "where\n" ++ + unlines [mkInst f xx | (f,xx) <- rules] + where + ec = elemCat cat + baseVars = mkVars (baseSize (cat,rules)) + mkInst f xx = let xx' = mkVars (length xx) in " gf " ++ + (if length xx == 0 then gId f else prParenth (gId f +++ foldr1 (+++) xx')) +++ + "=" +++ mkRHS f xx' + mkVars n = ["x" ++ show i | i <- [1..n]] + mkRHS f vars = "Fun (mkCId \"" ++ f ++ "\")" +++ + "[" ++ prTList ", " ["gf" +++ x | x <- vars] ++ "]" + + +----fInstance m ("Cn",_) = "" --- +fInstance m (cat,[]) = "" +fInstance m (cat,rules) = + " fg t =" ++++ + " case t of" ++++ + unlines [mkInst f xx | (f,xx) <- rules] ++++ + " _ -> error (\"no" +++ cat ++ " \" ++ show t)" + where + mkInst f xx = + " Fun i " ++ + "[" ++ prTList "," xx' ++ "]" +++ + "| i == mkCId \"" ++ f ++ "\" ->" +++ mkRHS f xx' + where xx' = ["x" ++ show i | (_,i) <- zip xx [1..]] + mkRHS f vars + | isListCat (cat,rules) = + if "Base" `isPrefixOf` f then + gId cat +++ "[" ++ prTList ", " [ "fg" +++ x | x <- vars ] ++ "]" + else + let (i,t) = (init vars,last vars) + in "let" +++ gId cat +++ "xs = fg " ++ t +++ "in" +++ + gId cat +++ prParenth (prTList ":" (["fg"+++v | v <- i] ++ ["xs"])) + | otherwise = + gId f +++ + prTList " " [prParenth ("fg" +++ x) | x <- vars] + + +--type HSkeleton = [(OIdent, [(OIdent, [OIdent])])] +hSkeleton :: PGF -> (String,HSkeleton) +hSkeleton gr = + (prCId (absname gr), + [(prCId c, [(prCId f, map prCId cs) | (f, (cs,_)) <- fs]) | + fs@((_, (_,c)):_) <- fns] + ) + where + fns = groupBy valtypg (sortBy valtyps (map jty (Map.assocs (funs (abstract gr))))) + valtyps (_, (_,x)) (_, (_,y)) = compare x y + valtypg (_, (_,x)) (_, (_,y)) = x == y + jty (f,(ty,_)) = (f,catSkeleton ty) + +updateSkeleton :: OIdent -> HSkeleton -> (OIdent, [OIdent]) -> HSkeleton +updateSkeleton cat skel rule = + case skel of + (cat0,rules):rr | cat0 == cat -> (cat0, rule:rules) : rr + (cat0,rules):rr -> (cat0, rules) : updateSkeleton cat rr rule + +isListCat :: (OIdent, [(OIdent, [OIdent])]) -> Bool +isListCat (cat,rules) = "List" `isPrefixOf` cat && length rules == 2 + && ("Base"++c) `elem` fs && ("Cons"++c) `elem` fs + where c = elemCat cat + fs = map fst rules + +-- | Gets the element category of a list category. +elemCat :: OIdent -> OIdent +elemCat = drop 4 + +isBaseFun :: OIdent -> Bool +isBaseFun f = "Base" `isPrefixOf` f + +isConsFun :: OIdent -> Bool +isConsFun f = "Cons" `isPrefixOf` f + +baseSize :: (OIdent, [(OIdent, [OIdent])]) -> Int +baseSize (_,rules) = length bs + where Just (_,bs) = find (("Base" `isPrefixOf`) . fst) rules |
