Make comparison on equalities work right (ie look at the types)

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

diff --git a/compiler/typecheck/TcRnTypes.lhs b/compiler/typecheck/TcRnTypes.lhs
index 20262c9..ebf4101 100644 (file)
--- a/compiler/typecheck/TcRnTypes.lhs
+++ b/compiler/typecheck/TcRnTypes.lhs
@@ -219,7 +219,7 @@ data TcGblEnv
                -- Nothing <=> Don't retain renamed decls
 
        tcg_binds     :: LHsBinds Id,       -- Value bindings in this module
-       tcg_deprecs   :: Deprecations,      -- ...Deprecations 
+       tcg_warns     :: Warnings,          -- ...Warnings and deprecations
        tcg_insts     :: [Instance],        -- ...Instances
        tcg_fam_insts :: [FamInst],         -- ...Family instances
        tcg_rules     :: [LRuleDecl Id],    -- ...Rules
@@ -234,9 +234,9 @@ type RecFieldEnv = NameEnv [Name]   -- Maps a constructor name *in this module*
                                        -- to the fields for that constructor
        -- This is used when dealing with ".." notation in record 
        -- construction and pattern matching.
-       -- The FieldEnv deals *only* with constructors defined in
-       -- *thie* module.  For imported modules, we get the same info
-       -- from the TypeEnv
+       -- The FieldEnv deals *only* with constructors defined in *thie*
+       -- module.  For imported modules, we get the same info from the
+       -- TypeEnv
 \end{code}
 
 %************************************************************************
@@ -730,7 +730,8 @@ than with the Avails handling stuff in TcSimplify
 
 \begin{code}
 instance Ord Inst where
-  compare = cmpInst
+   compare = cmpInst
+       -- Used *only* for AvailEnv in TcSimplify
 
 instance Eq Inst where
   (==) i1 i2 = case i1 `cmpInst` i2 of
@@ -761,11 +762,12 @@ cmpInst i1@(ImplicInst {}) i2@(ImplicInst {}) = tci_name i1 `compare` tci_name i
 cmpInst (ImplicInst {})    _                  = LT
 
        -- same for Equality constraints
-cmpInst (EqInst {})    (Dict {})             = GT
-cmpInst (EqInst {})    (Method {})           = GT
-cmpInst (EqInst {})    (LitInst {})          = GT
-cmpInst (EqInst {})    (ImplicInst {})       = GT
-cmpInst i1@(EqInst {}) i2@(EqInst {})         = tci_name i1 `compare` tci_name i2
+cmpInst (EqInst {})    (Dict {})       = GT
+cmpInst (EqInst {})    (Method {})     = GT
+cmpInst (EqInst {})    (LitInst {})    = GT
+cmpInst (EqInst {})    (ImplicInst {}) = GT
+cmpInst i1@(EqInst {}) i2@(EqInst {})  = (tci_left  i1 `tcCmpType` tci_left  i2) `thenCmp`
+                                         (tci_right i1 `tcCmpType` tci_right i2)
 \end{code}