Fix promoted HsTyVars on ghc-8.2.1

This fix does not work on ghc-8.0, because I do not understand
the 8.0 API in this instance. Could be resolved by looking
at annotations, but that really should not be necessary.

src-literatetests/15-regressions.blt

@@ -465,3 +465,15 @@ v = A {..} where b = 2
 {-# LANGUAGE RecordWildCards #-}
 v = A {a = 1, b = 2, c = 3}
 
+#test issue 63 a
+#pending fix does not work on 8.0.2
+test :: Proxy 'Int
+
+#test issue 63 b
+#pending fix does not work on 8.0.2
+test :: Proxy '[ 'True]
+
+#test issue 63 c
+#pending fix does not work on 8.0.2
+test :: Proxy '[Bool]
+

src/Language/Haskell/Brittany/Internal/LayouterBasics.hs

@@ -42,6 +42,7 @@ module Language.Haskell.Brittany.Internal.LayouterBasics
   , appSep
   , docCommaSep
   , docParenLSep
+  , docTick
   , spacifyDocs
   , briDocMToPPM
   , allocateNode
@@ -447,6 +448,9 @@ docCommaSep = appSep $ docLit $ Text.pack ","
 docParenLSep :: ToBriDocM BriDocNumbered
 docParenLSep = appSep $ docLit $ Text.pack "("
 
+docTick :: ToBriDocM BriDocNumbered
+docTick = docLit $ Text.pack "'"
+
 docNodeAnnKW
   :: Data.Data.Data ast
   => Located ast

src/Language/Haskell/Brittany/Internal/Layouters/Type.hs

@@ -29,12 +29,20 @@ layoutType :: ToBriDoc HsType
 layoutType ltype@(L _ typ) = docWrapNode ltype $ case typ of
   -- _ | traceShow (ExactPrint.Types.mkAnnKey ltype) False -> error "impossible"
 #if MIN_VERSION_ghc(8,2,0) /* ghc-8.2 */
-  HsTyVar _ name -> do
+  HsTyVar promoted name -> do
+    t <- lrdrNameToTextAnn name
+    case promoted of
+      Promoted -> docSeq
+        [ docSeparator
+        , docTick
+        , docWrapNode name $ docLit t
+        ]
+      NotPromoted -> docWrapNode name $ docLit t
 #else /* ghc-8.0 */
   HsTyVar name -> do
-#endif
     t <- lrdrNameToTextAnn name
     docWrapNode name $ docLit t
+#endif
   HsForAllTy bndrs (L _ (HsQualTy (L _ cntxts@(_:_)) typ2)) -> do
     typeDoc <- docSharedWrapper layoutType typ2
     tyVarDocs <- bndrs `forM` \case
@@ -294,7 +302,7 @@ layoutType ltype@(L _ typ) = docWrapNode ltype $ case typ of
     docAlt
       [ docSeq
         [ docForceSingleline typeDoc1
-        , docLit $ Text.pack " "
+        , docSeparator
         , docForceSingleline typeDoc2
         ]
       , docPar
@@ -324,7 +332,7 @@ layoutType ltype@(L _ typ) = docWrapNode ltype $ case typ of
     docAlt
       [ docSeq
       $ docForceSingleline docHead : (docRest >>= \d ->
-        [ docLit $ Text.pack " ", docForceSingleline d ])
+        [ docSeparator, docForceSingleline d ])
       , docPar docHead (docLines $ docEnsureIndent BrIndentRegular <$> docRest)
       ]
   HsAppsTy (typHead:typRest) -> do
@@ -333,7 +341,7 @@ layoutType ltype@(L _ typ) = docWrapNode ltype $ case typ of
     docAlt
       [ docSeq
       $ docForceSingleline docHead : (docRest >>= \d ->
-        [ docLit $ Text.pack " ", docForceSingleline d ])
+        [ docSeparator, docForceSingleline d ])
       , docPar docHead (docLines $ docEnsureIndent BrIndentRegular <$> docRest)
       ]
     where