[project @ 2000-04-05 16:25:51 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcExpr.lhs

diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs
index 9ab1460..8063961 100644 (file)
--- a/ghc/compiler/typecheck/TcExpr.lhs
+++ b/ghc/compiler/typecheck/TcExpr.lhs
@@ -14,7 +14,7 @@ import HsSyn          ( HsExpr(..), HsLit(..), ArithSeqInfo(..),
                        )
 import RnHsSyn         ( RenamedHsExpr, RenamedRecordBinds )
 import TcHsSyn         ( TcExpr, TcRecordBinds, mkHsConApp,
-                         mkHsTyApp, mkHsLet, maybeBoxedPrimType
+                         mkHsTyApp, mkHsLet
                        )
 
 import TcMonad
@@ -35,7 +35,7 @@ import TcEnv          ( tcInstId,
                          tcLookupTyCon, tcLookupDataCon
                        )
 import TcMatches       ( tcMatchesCase, tcMatchLambda, tcStmts )
-import TcMonoType      ( tcHsType, checkSigTyVars, sigCtxt )
+import TcMonoType      ( tcHsSigType, checkSigTyVars, sigCtxt )
 import TcPat           ( badFieldCon )
 import TcSimplify      ( tcSimplify, tcSimplifyAndCheck, partitionPredsOfLIE )
 import TcType          ( TcType, TcTauType,
@@ -131,6 +131,7 @@ tcPolyExpr arg expected_arg_ty
     tcInstTcType expected_arg_ty       `thenNF_Tc` \ (sig_tyvars, sig_rho) ->
     let
        (sig_theta, sig_tau) = splitRhoTy sig_rho
+       free_tyvars          = tyVarsOfType expected_arg_ty
     in
        -- Type-check the arg and unify with expected type
     tcMonoExpr arg sig_tau                             `thenTc` \ (arg', lie_arg) ->
@@ -146,10 +147,10 @@ tcPolyExpr arg expected_arg_ty
        -- Conclusion: include the free vars of the expected arg type in the
        -- list of "free vars" for the signature check.
 
-    tcExtendGlobalTyVars (tyVarsOfType expected_arg_ty)                $
-    tcAddErrCtxtM (sigCtxt sig_msg expected_arg_ty)            $
+    tcExtendGlobalTyVars free_tyvars                             $
+    tcAddErrCtxtM (sigCtxt sig_msg sig_tyvars sig_theta sig_tau)  $
 
-    checkSigTyVars sig_tyvars                  `thenTc` \ zonked_sig_tyvars ->
+    checkSigTyVars sig_tyvars free_tyvars      `thenTc` \ zonked_sig_tyvars ->
 
     newDicts SignatureOrigin sig_theta         `thenNF_Tc` \ (sig_dicts, dict_ids) ->
        -- ToDo: better origin
@@ -170,8 +171,7 @@ tcPolyExpr arg expected_arg_ty
     returnTc ( generalised_arg, free_insts,
               arg', sig_tau, lie_arg )
   where
-    sig_msg ty = sep [ptext SLIT("In an expression with expected type:"),
-                     nest 4 (ppr ty)]
+    sig_msg = ptext SLIT("When checking an expression type signature")
 \end{code}
 
 %************************************************************************
@@ -390,8 +390,7 @@ tcMonoExpr (HsCCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty
        -- constraints on the argument and result types.
     mapNF_Tc new_arg_dict (zipEqual "tcMonoExpr:CCall" args arg_tys)   `thenNF_Tc` \ ccarg_dicts_s ->
     newClassDicts result_origin [(cReturnableClass, [result_ty])]      `thenNF_Tc` \ (ccres_dict, _) ->
-    returnTc (mkHsConApp ioDataCon [result_ty] [HsCCall lbl args' may_gc is_asm result_ty],
-                     -- do the wrapping in the newtype constructor here
+    returnTc (HsCCall lbl args' may_gc is_asm io_result_ty,
              foldr plusLIE ccres_dict ccarg_dicts_s `plusLIE` args_lie)
 \end{code}
 
@@ -699,7 +698,7 @@ tcMonoExpr in_expr@(ArithSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty
 \begin{code}
 tcMonoExpr in_expr@(ExprWithTySig expr poly_ty) res_ty
  = tcSetErrCtxt (exprSigCtxt in_expr)  $
-   tcHsType  poly_ty           `thenTc` \ sig_tc_ty ->
+   tcHsSigType  poly_ty                `thenTc` \ sig_tc_ty ->
 
    if not (isForAllTy sig_tc_ty) then
        -- Easy case