GF/src is now for 2.9, and the new sources are in src-3.0 - keep it this way until the release of GF 3

src-3.0/GF/API/GrammarToTransfer.hs

@@ -0,0 +1,94 @@
+----------------------------------------------------------------------
+-- |
+-- Module      : GrammarToTransfer
+-- Maintainer  : Björn Bringert
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 2005/06/17 12:39:07 $ 
+-- > CVS $Author: bringert $
+-- > CVS $Revision: 1.8 $
+--
+-- Creates a data type definition in the transfer language
+-- for an abstract module.
+-----------------------------------------------------------------------------
+
+module GF.API.GrammarToTransfer (grammar2transfer) where
+
+import qualified GF.Canon.GFC as GFC
+import qualified GF.Grammar.Abstract as A
+import GF.Grammar.Macros
+
+import GF.Infra.Modules
+import GF.Data.Operations
+
+import Transfer.Syntax.Abs as S
+import Transfer.Syntax.Print
+
+
+-- | the main function
+grammar2transfer :: GFC.CanonGrammar -> String
+grammar2transfer gr = printTree $ S.Module imports decls
+  where
+  cat = S.Ident "Cat" -- FIXME
+  tree = S.Ident "Tree" -- FIXME
+  defs = concat [tree2list (jments m) | im@(_,ModMod m) <- modules gr, isModAbs m]
+  -- get category name and context
+  cats = [(cat, c) | (cat,GFC.AbsCat c _) <- defs]
+  -- get function name and type
+  funs = [(fun, typ) | (fun,GFC.AbsFun typ _) <- defs]
+  name = ifNull "UnknownModule" (symid . last) [n | (n,ModMod m) <- modules gr, isModAbs m]
+  imports = [Import (S.Ident "prelude")]
+  decls = [cats2cat cat tree cats, funs2tree cat tree funs] ++ instances tree
+
+
+-- | Create a declaration of the type of categories given a list
+--   of category names and their contexts.
+cats2cat :: S.Ident -- ^ the name of the Cat type
+         -> S.Ident -- ^ the name of the Tree type
+         -> [(A.Ident,A.Context)] -> Decl
+cats2cat cat tree = S.DataDecl cat S.EType . map (uncurry catCons)
+  where
+  catCons i c = S.ConsDecl (id2id i) (catConsType c)
+  catConsType = foldr pi (S.EVar cat)
+  pi (i,x) t = mkPi (id2pv i) (addTree tree $ term2exp x) t
+
+funs2tree :: S.Ident -- ^ the name of the Cat type
+          -> S.Ident -- ^ the name of the Tree type
+          -> [(A.Ident,A.Type)] -> Decl
+funs2tree cat tree = 
+    S.DataDecl tree (S.EPiNoVar (S.EVar cat) S.EType) . map (uncurry funCons)
+  where 
+  funCons i t = S.ConsDecl (id2id i) (addTree tree $ term2exp t)
+
+term2exp :: A.Term -> S.Exp
+term2exp t = case t of
+  A.Vr i         -> S.EVar (id2id i)
+  A.App t1 t2    -> S.EApp (term2exp t1) (term2exp t2)
+  A.Abs i t1     -> S.EAbs (id2pv i) (term2exp t1)
+  A.Prod i t1 t2 -> mkPi (id2pv i) (term2exp t1) (term2exp t2)
+  A.Q m i        -> S.EVar (id2id i)
+  _ -> error $ "term2exp: can't handle " ++ show t
+
+mkPi :: S.VarOrWild -> S.Exp -> S.Exp -> S.Exp 
+mkPi VWild t e = S.EPiNoVar t e
+mkPi v     t e = S.EPi v t e
+
+id2id :: A.Ident -> S.Ident
+id2id = S.Ident . symid
+
+id2pv :: A.Ident -> S.VarOrWild
+id2pv i = case symid i of
+                       "h_" -> S.VWild -- FIXME: hacky?
+                       x    -> S.VVar (S.Ident x)
+
+-- FIXME: I think this is not general enoguh.
+addTree :: S.Ident -> S.Exp -> S.Exp
+addTree tree x = case x of
+  S.EPi i t e -> S.EPi i (addTree tree t) (addTree tree e)
+  S.EPiNoVar t e -> S.EPiNoVar (addTree tree t) (addTree tree e)
+  e -> S.EApp (S.EVar tree) e
+
+instances :: S.Ident -> [S.Decl]
+instances tree = [DeriveDecl (S.Ident "Eq") tree, 
+                  DeriveDecl (S.Ident "Compos") tree]