Introducing a datatype for WorkLists that properly prioritizes equalities.

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

diff --git a/compiler/typecheck/TcBinds.lhs b/compiler/typecheck/TcBinds.lhs
index 0da6cdb..8a6a3b7 100644 (file)
--- a/compiler/typecheck/TcBinds.lhs
+++ b/compiler/typecheck/TcBinds.lhs
@@ -325,11 +325,13 @@ tcPolyBinds :: TopLevelFlag -> SigFun -> PragFun
 tcPolyBinds top_lvl sig_fn prag_fn rec_group rec_tc bind_list
   = setSrcSpan loc                              $
     recoverM (recoveryCode binder_names sig_fn) $ do 
-        -- Set up main recoer; take advantage of any type sigs
+        -- Set up main recover; take advantage of any type sigs
 
     { traceTc "------------------------------------------------" empty
     ; traceTc "Bindings for" (ppr binder_names)
 
+    -- Instantiate the polytypes of any binders that have signatures
+    -- (as determined by sig_fn), returning a TcSigInfo for each
     ; tc_sig_fn <- tcInstSigs sig_fn binder_names
 
     ; dflags <- getDOpts
@@ -348,9 +350,10 @@ tcPolyBinds top_lvl sig_fn prag_fn rec_group rec_tc bind_list
     ; return (binds, poly_ids) }
   where
     binder_names = collectHsBindListBinders bind_list
-    loc = getLoc (head bind_list)
-         -- TODO: location a bit awkward, but the mbinds have been
-         --       dependency analysed and may no longer be adjacent
+    loc = foldr1 combineSrcSpans (map getLoc bind_list)
+         -- The mbinds have been dependency analysed and 
+         -- may no longer be adjacent; so find the narrowest
+        -- span that includes them all
 
 ------------------
 tcPolyNoGen 
@@ -388,7 +391,7 @@ tcPolyCheck :: TcSigInfo -> PragFun
 --   it binds a single variable,
 --   it has a signature,
 tcPolyCheck sig@(TcSigInfo { sig_id = id, sig_tvs = tvs, sig_scoped = scoped
-                           , sig_theta = theta, sig_tau = tau, sig_loc = loc })
+                           , sig_theta = theta, sig_tau = tau })
     prag_fn rec_tc bind_list
   = do { ev_vars <- newEvVars theta
        ; let skol_info = SigSkol (FunSigCtxt (idName id)) (mkPhiTy theta tau)
@@ -399,6 +402,7 @@ tcPolyCheck sig@(TcSigInfo { sig_id = id, sig_tvs = tvs, sig_scoped = scoped
 
        ; export <- mkExport prag_fn tvs theta mono_info
 
+       ; loc <- getSrcSpanM
        ; let (_, poly_id, _, _) = export
              abs_bind = L loc $ AbsBinds 
                         { abs_tvs = tvs
@@ -415,10 +419,10 @@ tcPolyInfer
                    -- dependencies based on type signatures
   -> [LHsBind Name]
   -> TcM (LHsBinds TcId, [TcId])
-tcPolyInfer top_lvl mono sig_fn prag_fn rec_tc bind_list
+tcPolyInfer top_lvl mono tc_sig_fn prag_fn rec_tc bind_list
   = do { ((binds', mono_infos), wanted) 
              <- captureConstraints $
-                tcMonoBinds sig_fn LetLclBndr rec_tc bind_list
+                tcMonoBinds tc_sig_fn LetLclBndr rec_tc bind_list
 
        ; unifyCtxts [sig | (_, Just sig, _) <- mono_infos]