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

1 files changed, 159 insertions, 0 deletions

diff --git a/src-3.0/GF/Grammar/AppPredefined.hs b/src-3.0/GF/Grammar/AppPredefined.hs
new file mode 100644
index 000000000..fa0048c80
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+++ b/src-3.0/GF/Grammar/AppPredefined.hs
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+----------------------------------------------------------------------
+-- |
+-- Module      : AppPredefined
+-- Maintainer  : AR
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 2005/10/06 14:21:34 $ 
+-- > CVS $Author: aarne $
+-- > CVS $Revision: 1.13 $
+--
+-- Predefined function type signatures and definitions.
+-----------------------------------------------------------------------------
+
+module GF.Grammar.AppPredefined (isInPredefined, typPredefined, appPredefined
+		     ) where
+
+import GF.Data.Operations
+import GF.Grammar.Grammar
+import GF.Infra.Ident
+import GF.Grammar.Macros
+import GF.Grammar.PrGrammar (prt,prt_,prtBad)
+---- import PGrammar (pTrm)
+
+-- predefined function type signatures and definitions. AR 12/3/2003.
+
+isInPredefined :: Ident -> Bool
+isInPredefined = err (const True) (const False) . typPredefined
+
+typPredefined :: Ident -> Err Type
+typPredefined c@(IC f) = case f of
+  "Int"    -> return typePType
+  "Float"  -> return typePType
+  "Error"  -> return typeType
+  "Ints"   -> return $ mkFunType [cnPredef "Int"] typePType
+  "PBool"  -> return typePType
+  "error"  -> return $ mkFunType [typeStr] (cnPredef "Error")  -- non-can. of empty set
+  "PFalse" -> return $ cnPredef "PBool"
+  "PTrue"  -> return $ cnPredef "PBool"
+  "dp"     -> return $ mkFunType [cnPredef "Int",typeTok] typeTok
+  "drop"   -> return $ mkFunType [cnPredef "Int",typeTok] typeTok
+  "eqInt"  -> return $ mkFunType [cnPredef "Int",cnPredef "Int"] (cnPredef "PBool")
+  "lessInt"-> return $ mkFunType [cnPredef "Int",cnPredef "Int"] (cnPredef "PBool")
+  "eqStr"  -> return $ mkFunType [typeTok,typeTok] (cnPredef "PBool")
+  "length" -> return $ mkFunType [typeTok] (cnPredef "Int")
+  "occur"  -> return $ mkFunType [typeTok,typeTok] (cnPredef "PBool")
+  "occurs" -> return $ mkFunType [typeTok,typeTok] (cnPredef "PBool")
+  "plus"   -> return $ mkFunType [cnPredef "Int",cnPredef "Int"] (cnPredef "Int")
+----  "read"   -> (P : Type) -> Tok -> P
+  "show"   -> return $ mkProd -- (P : PType) -> P -> Tok
+    ([(zIdent "P",typePType),(wildIdent,Vr (zIdent "P"))],typeStr,[]) 
+  "toStr"  -> return $ mkProd -- (L : Type)  -> L -> Str
+    ([(zIdent "L",typeType),(wildIdent,Vr (zIdent "L"))],typeStr,[]) 
+  "mapStr" -> 
+    let ty = zIdent "L" in
+    return $ mkProd -- (L : Type)  -> (Str -> Str) -> L -> L
+    ([(ty,typeType),(wildIdent,mkFunType [typeStr] typeStr),(wildIdent,Vr ty)],Vr ty,[]) 
+  "take"   -> return $ mkFunType [cnPredef "Int",typeTok] typeTok
+  "tk"     -> return $ mkFunType [cnPredef "Int",typeTok] typeTok
+  _        -> prtBad "unknown in Predef:" c
+typPredefined c = prtBad "unknown in Predef:" c
+
+appPredefined :: Term -> Err (Term,Bool)
+appPredefined t = case t of
+
+  App f x0 -> do
+   (x,_) <- appPredefined x0
+   case f of
+    -- one-place functions
+    Q (IC "Predef") (IC f) -> case (f, x) of
+      ("length", K s) -> retb $ EInt $ toInteger $ length s
+      _ -> retb t ---- prtBad "cannot compute predefined" t
+
+    -- two-place functions
+    App (Q (IC "Predef") (IC f)) z0 -> do
+     (z,_) <- appPredefined z0
+     case (f, norm z, norm x) of
+      ("drop", EInt i, K s) -> retb $ K (drop (fi i) s)
+      ("take", EInt i, K s) -> retb $ K (take (fi i) s)
+      ("tk",   EInt i, K s) -> retb $ K (take (max 0 (length s - fi i)) s)
+      ("dp",   EInt i, K s) -> retb $ K (drop (max 0 (length s - fi i)) s)
+      ("eqStr",K s,    K t) -> retb $ if s == t then predefTrue else predefFalse
+      ("occur",K s,    K t) -> retb $ if substring s t then predefTrue else predefFalse
+      ("occurs",K s,   K t) -> retb $ if any (flip elem t) s then predefTrue else predefFalse
+      ("eqInt",EInt i, EInt j) -> retb $ if i==j then predefTrue else predefFalse
+      ("lessInt",EInt i, EInt j) -> retb $ if i<j then predefTrue else predefFalse
+      ("plus", EInt i, EInt j) -> retb $ EInt $ i+j
+      ("show", _, t) -> retb $ foldr C Empty $ map K $ words $ prt t
+      ("read", _, K s) -> retb $ str2tag s --- because of K, only works for atomic tags
+      ("toStr", _, t) -> trm2str t >>= retb
+
+      _ -> retb t ---- prtBad "cannot compute predefined" t
+
+    -- three-place functions
+    App (App (Q (IC "Predef") (IC f)) z0) y0 -> do
+     (y,_) <- appPredefined y0
+     (z,_) <- appPredefined z0
+     case (f, z, y, x) of
+      ("mapStr",ty,op,t) -> retf $ mapStr ty op t
+      _ -> retb t ---- prtBad "cannot compute predefined" t
+
+    _ -> retb t ---- prtBad "cannot compute predefined" t
+  _ -> retb t
+                  ---- should really check the absence of arg variables
+ where
+   retb t = return (t,True)  -- no further computing needed
+   retf t = return (t,False) -- must be computed further
+   norm t = case t of
+     Empty -> K []
+     _ -> t
+   fi = fromInteger
+
+-- read makes variables into constants
+
+str2tag :: String -> Term
+str2tag s = case s of
+----  '\'' : cs -> mkCn $ pTrm $ init cs
+  _ -> Cn $ IC s ---
+ where
+   mkCn t = case t of
+     Vr i -> Cn i
+     App c a -> App (mkCn c) (mkCn a)
+     _ -> t
+
+
+predefTrue = Q (IC "Predef") (IC "PTrue")
+predefFalse = Q (IC "Predef") (IC "PFalse")
+
+substring :: String -> String -> Bool
+substring s t = case (s,t) of
+  (c:cs, d:ds) -> (c == d && substring cs ds) || substring s ds
+  ([],_) -> True
+  _ -> False
+
+trm2str :: Term -> Err Term
+trm2str t = case t of
+  R ((_,(_,s)):_) -> trm2str s
+  T _ ((_,s):_)   -> trm2str s
+  TSh _ ((_,s):_) -> trm2str s
+  V _ (s:_)       -> trm2str s
+  C _ _         -> return $ t
+  K _           -> return $ t
+  S c _         -> trm2str c
+  Empty         -> return $ t
+  _ -> prtBad "cannot get Str from term" t
+
+-- simultaneous recursion on type and term: type arg is essential!
+-- But simplify the task by assuming records are type-annotated
+-- (this has been done in type checking)
+mapStr :: Type -> Term -> Term -> Term
+mapStr ty f t = case (ty,t) of
+  _ | elem ty [typeStr,typeTok] -> App f t
+  (_,        R ts)    -> R [(l,mapField v)   | (l,v) <- ts]
+  (Table a b,T ti cs) -> T ti [(p,mapStr b f v) | (p,v) <- cs]
+  _    -> t 
+ where
+   mapField (mty,te) = case mty of
+     Just ty -> (mty,mapStr ty f te)
+     _ -> (mty,te)