Super-monster patch implementing the new typechecker -- at last

[ghc-hetmet.git] / compiler / types / FunDeps.lhs

diff --git a/compiler/types/FunDeps.lhs b/compiler/types/FunDeps.lhs
index 02b0a2a..0bea32f 100644 (file)
--- a/compiler/types/FunDeps.lhs
+++ b/compiler/types/FunDeps.lhs
@@ -9,8 +9,8 @@ It's better to read it as: "if we know these, then we're going to know these"
 
 \begin{code}
 module FunDeps (
-       Equation, pprEquation,
-       oclose, improveOne,
+       Equation, pprEquation, 
+       oclose, improveFromInstEnv, improveFromAnother,
        checkInstCoverage, checkFunDeps,
        pprFundeps
     ) where
@@ -200,6 +200,21 @@ NOTA BENE:
 \begin{code}
 type Pred_Loc = (PredType, SDoc)       -- SDoc says where the Pred comes from
 
+improveFromInstEnv :: (Class -> [Instance]) 
+                     -> Pred_Loc 
+                     -> [(Equation,Pred_Loc,Pred_Loc)]
+-- Improvement from top-level instances 
+improveFromInstEnv _inst_env pred 
+  = improveOne _inst_env pred []        -- TODO: Refactor to directly use instance_eqnd? 
+
+improveFromAnother :: Pred_Loc 
+                   -> Pred_Loc
+                   -> [(Equation,Pred_Loc,Pred_Loc)] 
+-- Improvement from another local (given or wanted) constraint
+improveFromAnother pred1 pred2 
+  = improveOne (\_ -> []) pred1 [pred2] -- TODO: Refactor to directly use pairwise_eqns?
+
+
 improveOne :: (Class -> [Instance])            -- Gives instances for given class
           -> Pred_Loc                          -- Do improvement triggered by this
           -> [Pred_Loc]                        -- Current constraints