= ParseError Pos String
| UnifyError Pos Type Type
| FieldSelectorError Pos Type FieldSelector
+ | UndeclaredVariableError Pos String
| Error String
:: Gamma
:: SemOutput :== Either [SemError] (AST, Gamma)
toString p,
"SemError: Cannot select ", toString fs, " from type: ",
toString t]
+ toString (UndeclaredVariableError p ident) = concat [
+ toString p, "SemError: identifier: ", ident, " undefined."]
sem :: AST -> SemOutput
sem (AST vd fd) = case runStateT m ('Map'.newMap, getRandomStream 1) of
>>= \t2-> unify (ListType t1) t2
typeExpr (EmptyListExpr p) = freshIdent >>= \frsh-> let t = IdType frsh in
putIdent frsh t >>| pure t
-//typeExpr (FunExpr p (FunCall f es)) = undef
+typeExpr (FunExpr p (FunCall f es)) = gets (\(st, r)->'Map'.get f st)
+ >>= \mt-> case mt of
+ Nothing = undef
+ Just t = unifyApp t es
//ignore field selectors
typeExpr (VarExpr p (VarDef ident fs)) = gets (\(st, r)->'Map'.get ident st)
- >>= \mt->case mt of
- Nothing = let t = IdType ident in putIdent ident t >>| pure t
- Just t = unify t fs
+ >>= \mt->case mt of
+ Nothing = liftT $ Left $ UndeclaredVariableError p ident
+ //let t = IdType ident in putIdent ident t >>| pure t
+ Just t = unify t fs
+
+unifyApp :: Type [Expr] -> Env Type
+unifyApp t [] = pure t //whoop whoop, functions can return functions
+unifyApp (tf1 ->> tf2) [t1:ts] = (->>) <$> unify tf1 t1 <*> (unifyApp tf2 ts)
+unifyApp t1 t2 = liftT $ Left $ UnifyError zero t1 (IdType "[expressions, FIXME")
class unify a :: Type a -> Env Type