Allow the old [$foo| ... |] syntax for quasi-quotes

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

diff --git a/compiler/typecheck/TcSplice.lhs b/compiler/typecheck/TcSplice.lhs
index aa5e9a1..0d7ba6a 100644 (file)
--- a/compiler/typecheck/TcSplice.lhs
+++ b/compiler/typecheck/TcSplice.lhs
@@ -344,7 +344,7 @@ tcBracket brack res_ty
        ; let brack_stage = Brack cur_stage pending_splices lie_var
 
        ; (meta_ty, lie) <- setStage brack_stage $
-                           getConstraints $
+                           captureConstraints $
                            tc_bracket cur_stage brack
 
        ; simplifyBracket lie
@@ -395,7 +395,7 @@ tc_bracket _ (DecBrG decls)
 
 tc_bracket _ (PatBr pat)
   = do { any_ty <- newFlexiTyVarTy liftedTypeKind
-       ; _ <- tcPat ThPatQuote pat any_ty unitTy $ 
+       ; _ <- tcPat ThPatQuote pat any_ty $ 
                return ()
        ; tcMetaTy patQTyConName }
        -- Result type is PatQ (= Q Pat)
@@ -487,7 +487,7 @@ tcTopSpliceExpr tc_action
                    -- if the type checker fails!
     setStage Splice $ 
     do {    -- Typecheck the expression
-         (expr', lie) <- getConstraints tc_action
+         (expr', lie) <- captureConstraints tc_action
         
        -- Solve the constraints
        ; const_binds <- simplifyTop lie
@@ -664,7 +664,17 @@ runQuasiQuote :: Outputable hs_syn
               -> MetaOps th_syn hs_syn 
               -> RnM hs_syn
 runQuasiQuote (HsQuasiQuote quoter q_span quote) quote_selector meta_ty meta_ops
-  = do { quoter' <- lookupOccRn quoter
+  = do  {     -- Drop the leading "$" from the quoter name, if present
+              -- This is old-style syntax, now deprecated
+              -- NB: when removing this backward-compat, remove
+              --     the matching code in Lexer.x (around line 310)
+          let occ_str = occNameString (rdrNameOcc quoter)
+        ; quoter <- ASSERT( not (null occ_str) )  -- Lexer ensures this
+                    if head occ_str /= '$' then return quoter
+                    else do { addWarn (deprecatedDollar quoter)
+                            ; return (mkRdrUnqual (mkVarOcc (tail occ_str))) }
+
+        ; quoter' <- lookupOccRn quoter
                -- We use lookupOcc rather than lookupGlobalOcc because in the
                -- erroneous case of \x -> [x| ...|] we get a better error message
                -- (stage restriction rather than out of scope).
@@ -709,6 +719,12 @@ quoteStageError :: Name -> SDoc
 quoteStageError quoter
   = sep [ptext (sLit "GHC stage restriction:") <+> ppr quoter,
          nest 2 (ptext (sLit "is used in a quasiquote, and must be imported, not defined locally"))]
+
+deprecatedDollar :: RdrName -> SDoc
+deprecatedDollar quoter
+  = hang (ptext (sLit "Deprecated syntax:"))
+       2 (ptext (sLit "quasiquotes no longer need a dollar sign:")
+          <+> ppr quoter)
 \end{code}
 
 
@@ -787,7 +803,7 @@ runMeta show_code run_and_convert expr
        ; hsc_env <- getTopEnv
        ; src_span <- getSrcSpanM
        ; either_hval <- tryM $ liftIO $
-                        HscMain.compileExpr hsc_env src_span ds_expr
+                        HscMain.hscCompileCoreExpr hsc_env src_span ds_expr
        ; case either_hval of {
            Left exn   -> failWithTc (mk_msg "compile and link" exn) ;
            Right hval -> do