Changeset 15440 for src/Pugs/Prim/Keyed.hs

Timestamp:

03/04/07 14:41:52 (21 months ago)

Author:

audreyt

Message:

* Pugs.Prim.Keyed: Use gaal++'s fixpoint trick to refactor

the fallthrough case; also work with the new VV.

Files:

• src/Pugs/Prim/Keyed.hs (modified) (4 diffs)

src/Pugs/Prim/Keyed.hs

@@ -9 +9 @@
   existsFromRef, deleteFromRef,
 ) where
-import Pugs.Internals (forM, genericLength)
+import Pugs.Internals (forM, genericLength, fix)
 import Pugs.AST
 import Pugs.Types
@@ -23 +23 @@
     return $ map (VRef . MkRef . IPair) (keys `zip` elems)
 pairsFromVal (VRef ref) = pairsFromRef ref
-pairsFromVal v = retError "Not a keyed reference" v
+pairsFromVal v = fix err v
+
+err :: (Val -> Eval b) -> Val -> Eval b
+err f v@(VV vv) = do
+    val <- vvToVal vv
+    case val of
+        VV{} -> retError "Not a keyed object" v
+        _    -> f val
+err f v = retError "Not a keyed value" v
 
 keysFromVal :: Val -> Eval Val
@@ -34 +42 @@
     vals <- keysFromRef ref
     return $ VList vals
-keysFromVal v = retError "Not a keyed reference" v
+keysFromVal v = fix err v
 
 valuesFromVal :: Val -> Eval Val
@@ -46 +54 @@
     pairs <- hash_fetch sv
     return . VList $ Map.elems pairs
-valuesFromVal v = retError "Not a keyed reference" v
+valuesFromVal v = fix err v
 
 -- XXX These bulks of code below screams for refactoring