(Another) minor refactoring of substitutions

No change in functionality here, but greater clarity:

* In FamInstEnv.FlattenEnv, kill off the fi_in_scope field
  We are already maintaining an in-scope set in the fe_subst field,
  so it's silly do to it twice.

  (This isn't strictly connected to the rest of this patch, but
  the nomenclature changes below affect the same code, so I put
  them together.)

* TyCoRep.extendTCVSubst used to take a TyVar or a CoVar and work
  out what to do, but in fact we almost always know which of the
  two we are doing.  So:
    - define extendTvSubst, extendCvSubst
    - and use them

* Similar renamings in TyCoRep:
   - extendTCvSubstList        -->   extendTvSubstList
   - extendTCvSubstBinder      -->   extendTvSubstBinder
   - extendTCvSubstAndInScope  --> extendTvSubstAndInScope

* Add Type.extendTvSubstWithClone, extendCvSubstWithClone

* Similar nomenclature changes in Subst, SimplEnv, Specialise

* Kill off TyCoRep.substTelescope (never used)

1 files changed, 6 insertions, 6 deletions

diff --git a/compiler/specialise/Specialise.hs b/compiler/specialise/Specialise.hs
index bccf600c10..443998b5fe 100644
--- a/compiler/specialise/Specialise.hs
+++ b/compiler/specialise/Specialise.hs
@@ -10,8 +10,8 @@ module Specialise ( specProgram, specUnfolding ) where
 #include "HsVersions.h"
 
 import Id
-import TcType hiding( substTy, extendTCvSubstList )
-import Type   hiding( substTy, extendTCvSubstList )
+import TcType hiding( substTy )
+import Type   hiding( substTy, extendTvSubstList )
 import Coercion( Coercion )
 import Module( Module, HasModule(..) )
 import CoreMonad
@@ -1241,7 +1241,7 @@ specCalls mb_mod env rules_for_me calls_for_me fn rhs
                 -- spec_tyvars = [a,c]
                 -- ty_args     = [t1,b,t3]
                 spec_tv_binds = [(tv,ty) | (tv, Just ty) <- rhs_tyvars `zip` call_ts]
-                env1          = extendTCvSubstList env spec_tv_binds
+                env1          = extendTvSubstList env spec_tv_binds
                 (rhs_env, poly_tyvars) = substBndrs env1
                                             [tv | (tv, Nothing) <- rhs_tyvars `zip` call_ts]
 
@@ -2133,9 +2133,9 @@ mapAndCombineSM f (x:xs) = do (y, uds1) <- f x
                               (ys, uds2) <- mapAndCombineSM f xs
                               return (y:ys, uds1 `plusUDs` uds2)
 
-extendTCvSubstList :: SpecEnv -> [(TyVar,Type)] -> SpecEnv
-extendTCvSubstList env tv_binds
-  = env { se_subst = CoreSubst.extendTCvSubstList (se_subst env) tv_binds }
+extendTvSubstList :: SpecEnv -> [(TyVar,Type)] -> SpecEnv
+extendTvSubstList env tv_binds
+  = env { se_subst = CoreSubst.extendTvSubstList (se_subst env) tv_binds }
 
 substTy :: SpecEnv -> Type -> Type
 substTy env ty = CoreSubst.substTy (se_subst env) ty