[commit: ghc] master: More allDistinctTyVars from TcDeriv to Type (0451f91)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/0451f9137a73777170cd797406a1afb67cfb8916/ghc

>---------------------------------------------------------------

commit 0451f9137a73777170cd797406a1afb67cfb8916
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Tue Jun 24 22:19:24 2014 +0100

    More allDistinctTyVars from TcDeriv to Type
    
    Just a minor refactoring


>---------------------------------------------------------------

0451f9137a73777170cd797406a1afb67cfb8916
 compiler/typecheck/TcDeriv.lhs | 10 ----------
 compiler/types/Type.lhs        | 13 +++++++++++--
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs
index 492a99e..1d7936d 100644
--- a/compiler/typecheck/TcDeriv.lhs
+++ b/compiler/typecheck/TcDeriv.lhs
@@ -1444,16 +1444,6 @@ cond_functorOK allowFunctions (_, rep_tc, _)
     functions   = ptext (sLit "must not contain function types")
     wrong_arg   = ptext (sLit "must use the type variable only as the last argument of a data type")
 
-allDistinctTyVars :: [KindOrType] -> Bool
-allDistinctTyVars tkvs = go emptyVarSet tkvs
-  where
-    go _      [] = True
-    go so_far (ty : tys)
-       = case getTyVar_maybe ty of
-             Nothing -> False
-             Just tv | tv `elemVarSet` so_far -> False
-                     | otherwise -> go (so_far `extendVarSet` tv) tys
-
 checkFlag :: ExtensionFlag -> Condition
 checkFlag flag (dflags, _, _)
   | xopt flag dflags = Nothing
diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index 808216f..55df6432 100644
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -36,7 +36,7 @@ module Type (
 
         mkForAllTy, mkForAllTys, splitForAllTy_maybe, splitForAllTys,
         mkPiKinds, mkPiType, mkPiTypes,
-        applyTy, applyTys, applyTysD, isForAllTy, dropForAlls,
+        applyTy, applyTys, applyTysD, dropForAlls,
 
         mkNumLitTy, isNumLitTy,
         mkStrLitTy, isStrLitTy,
@@ -63,7 +63,7 @@ module Type (
         funTyCon,
 
         -- ** Predicates on types
-        isTypeVar, isKindVar,
+        isTypeVar, isKindVar, allDistinctTyVars, isForAllTy,
         isTyVarTy, isFunTy, isDictTy, isPredTy, isVoidTy,
 
         -- (Lifting and boxity)
@@ -323,6 +323,15 @@ getTyVar_maybe ty | Just ty' <- coreView ty = getTyVar_maybe ty'
 getTyVar_maybe (TyVarTy tv)                 = Just tv
 getTyVar_maybe _                            = Nothing
 
+allDistinctTyVars :: [KindOrType] -> Bool
+allDistinctTyVars tkvs = go emptyVarSet tkvs
+  where
+    go _      [] = True
+    go so_far (ty : tys)
+       = case getTyVar_maybe ty of
+             Nothing -> False
+             Just tv | tv `elemVarSet` so_far -> False
+                     | otherwise -> go (so_far `extendVarSet` tv) tys
 \end{code}