X-Git-Url: https://ruin.nu/git/?p=proglang.git;a=blobdiff_plain;f=Interpret.hs;h=5a792b9b2bbbe27be026d99096d17df1ef5cffa2;hp=9e4dcff34541b1f180b73b3c12dc15cbcfb3e642;hb=565fbd61dca527c23888e08783d0d91cee458524;hpb=3cee522d1f54b39a1efa654da364c6c939cbcf1f diff --git a/Interpret.hs b/Interpret.hs index 9e4dcff..5a792b9 100644 --- a/Interpret.hs +++ b/Interpret.hs @@ -23,7 +23,6 @@ eval (EBool b) = return (VBool b) eval (EInt n) = return (VInt n) eval (EVar i) = getVariableValue i eval (EAss i e) = setVariableValue i e -eval EDefault = error "EDefault called from an illegal place" eval (BiOpExp e o e') = do v <- eval e v'<- eval e' @@ -78,11 +77,6 @@ findVariable i (m:ms) = if member i m then lookup i m else findVariable i ms --setVariableValue :: (MonadState Variables m) => Ident -> Exp -> m Value --setVariableValue :: (MonadState Variables m) => Ident -> Exp -> m Value -addVariable :: Ident -> Exp -> StateT Variables IO () -addVariable i e = do - e' <- eval e - (m:ms) <- get - put $ (insert i e' m):ms setVariableValue :: Ident -> Exp -> StateT Variables IO Value setVariableValue i e = do @@ -113,9 +107,7 @@ execute (SBlock ss) = do execute (SWhile e s) = do (VBool b) <- eval e if b then execute s >> execute (SWhile e s) else return () -execute (SDecl t i EDefault) = do - case t of - TInt -> addVariable i (EInt 0) - TBool -> addVariable i (EBool False) - return () -execute (SDecl t i e) = addVariable i e >> return () +execute (SDecl t i e) =do + e' <- eval e + (m:ms) <- get + put $ (insert i e' m):ms