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authoraarne <aarne@cs.chalmers.se>2008-06-25 16:54:35 +0000
committeraarne <aarne@cs.chalmers.se>2008-06-25 16:54:35 +0000
commite9e80fc389365e24d4300d7d5390c7d833a96c50 (patch)
treef0b58473adaa670bd8fc52ada419d8cad470ee03 /src/GF/Compile/GFCCtoHaskell.hs
parentb96b36f43de3e2f8b58d5f539daa6f6d47f25870 (diff)
changed names of resource-1.3; added a note on homepage on release
Diffstat (limited to 'src/GF/Compile/GFCCtoHaskell.hs')
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1 files changed, 213 insertions, 0 deletions
diff --git a/src/GF/Compile/GFCCtoHaskell.hs b/src/GF/Compile/GFCCtoHaskell.hs
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+++ b/src/GF/Compile/GFCCtoHaskell.hs
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+----------------------------------------------------------------------
+-- |
+-- 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