MonadTransformers work

[cc1516.git] / sem.dcl

diff --git a/sem.dcl b/sem.dcl
index 92f1d51..b34bbc3 100644 (file)
--- a/sem.dcl
+++ b/sem.dcl
@@ -1,7 +1,17 @@
 definition module sem
 
 from Data.Either import :: Either
-from AST import :: AST
-from lex import :: Error
+from AST import :: AST, :: Pos, :: Type
+from StdOverloaded import class toString
 
-semanticAnalysis :: AST -> Either String AST
+:: SemError 
+       = ParseError Pos String 
+       | UnifyError Pos Type Type 
+       | UnifyErrorStub Type Type 
+       | Error String
+:: SemOutput :== Either [SemError] AST
+
+
+instance toString SemError
+
+sem :: AST -> SemOutput