Remove old coercion pretty-printer

Now, all coercions are printed from IfaceType, just like types.

This also changes the rendering of TransCo to use ; instead of
a prefix operator.

1 files changed, 28 insertions, 7 deletions

diff --git a/compiler/types/TyCoRep.hs b/compiler/types/TyCoRep.hs
index 9b82ab80f9..ca3a4ad32b 100644
--- a/compiler/types/TyCoRep.hs
+++ b/compiler/types/TyCoRep.hs
@@ -62,10 +62,12 @@ module TyCoRep (
         pprTyVar, pprTyVars,
         pprThetaArrowTy, pprClassPred,
         pprKind, pprParendKind, pprTyLit,
-        TyPrec(..), maybeParen, pprTcAppCo,
+        TyPrec(..), maybeParen,
         pprPrefixApp, pprArrowChain,
         pprDataCons, ppSuggestExplicitKinds,
 
+        pprCo, pprParendCo,
+
         -- * Free variables
         tyCoVarsOfType, tyCoVarsOfTypeDSet, tyCoVarsOfTypes, tyCoVarsOfTypesDSet,
         tyCoFVsBndr, tyCoFVsOfType, tyCoVarsOfTypeList,
@@ -139,13 +141,14 @@ import {-# SOURCE #-} DataCon( dataConFullSig
 import {-# SOURCE #-} Type( isPredTy, isCoercionTy, mkAppTy, mkCastTy
                           , tyCoVarsOfTypeWellScoped
                           , tyCoVarsOfTypesWellScoped
+                          , toposortTyVars
                           , coreView, typeKind )
    -- Transitively pulls in a LOT of stuff, better to break the loop
 
 import {-# SOURCE #-} Coercion
 import {-# SOURCE #-} ConLike ( ConLike(..), conLikeName )
 import {-# SOURCE #-} ToIface( toIfaceTypeX, toIfaceTyLit, toIfaceForAllBndr
-                             , toIfaceTyCon, toIfaceTcArgs, toIfaceCoercion )
+                             , toIfaceTyCon, toIfaceTcArgs, toIfaceCoercionX )
 
 -- friends:
 import IfaceType
@@ -2473,6 +2476,29 @@ tidyToIfaceType ty = toIfaceTypeX (mkVarSet free_tcvs) (tidyType env ty)
     free_tcvs = tyCoVarsOfTypeWellScoped ty
 
 ------------
+pprCo, pprParendCo :: Coercion -> SDoc
+pprCo       co = getPprStyle $ \ sty -> pprIfaceCoercion (tidyToIfaceCoSty co sty)
+pprParendCo co = getPprStyle $ \ sty -> pprParendIfaceCoercion (tidyToIfaceCoSty co sty)
+
+tidyToIfaceCoSty :: Coercion -> PprStyle -> IfaceCoercion
+tidyToIfaceCoSty co sty
+  | userStyle sty = tidyToIfaceCo co
+  | otherwise     = toIfaceCoercionX (tyCoVarsOfCo co) co
+     -- in latter case, don't tidy, as we'll be printing uniques.
+
+tidyToIfaceCo :: Coercion -> IfaceCoercion
+-- It's vital to tidy before converting to an IfaceType
+-- or nested binders will become indistinguishable!
+--
+-- Also for the free type variables, tell toIfaceCoercionX to
+-- leave them as IfaceFreeCoVar.  This is super-important
+-- for debug printing.
+tidyToIfaceCo co = toIfaceCoercionX (mkVarSet free_tcvs) (tidyCo env co)
+  where
+    env       = tidyFreeTyCoVars emptyTidyEnv free_tcvs
+    free_tcvs = toposortTyVars $ tyCoVarsOfCoList co
+
+------------
 pprClassPred :: Class -> [Type] -> SDoc
 pprClassPred clas tys = pprTypeApp (classTyCon clas) tys
 
@@ -2596,11 +2622,6 @@ pprTypeApp tc tys
                             (toIfaceTcArgs tc tys)
     -- TODO: toIfaceTcArgs seems rather wasteful here
 
-pprTcAppCo :: TyPrec -> (TyPrec -> Coercion -> SDoc)
-           -> TyCon -> [Coercion] -> SDoc
-pprTcAppCo p _pp tc cos
-  = pprIfaceCoTcApp p (toIfaceTyCon tc) (map toIfaceCoercion cos)
-
 ------------------
 
 pprPrefixApp :: TyPrec -> SDoc -> [SDoc] -> SDoc