Haddock support for bundled pattern synonyms (#627)

* Haddock support for bundled pattern synonyms

* Add fixities to bundled pattern synonyms

* Add bundled pattern synonyms to the synopsis

* Store bundled pattern fixities in expItemFixities

* Add test for bundled pattern synonyms

* Stop threading fixities

* Include bundled pattern synonyms for re-exported data types

Sadly, fixity information isn't found for re-exported data types

* Support for pattern synonyms

* Modify tests after #631

* Test some reexport variations

* Also lookup bundled pattern synonyms from `InstalledInterface`s

* Check isExported for bundled pattern synonyms

* Pattern synonym is exported check

* Always look for pattern synonyms in the current module

Another overlooked cornercase

* Account for types named twice in export lists

Also introduce a fast function for nubbing on a `Name` and use it
throughout the code base.

* correct fixities for reexported pattern synonyms

* Fuse concatMap and map

* Remove obsolete import

* Add pattern synonyms to visible exports

* Fix test

* Remove corner case

1 files changed, 9 insertions, 3 deletions

diff --git a/haddock-api/src/Haddock/Interface/Rename.hs b/haddock-api/src/Haddock/Interface/Rename.hs
index b43860fb..5820c61e 100644
--- a/haddock-api/src/Haddock/Interface/Rename.hs
+++ b/haddock-api/src/Haddock/Interface/Rename.hs
@@ -55,7 +55,7 @@ renameInterface dflags renamingEnv warnings iface =
 
       -- combine the missing names and filter out the built-ins, which would
       -- otherwise always be missing.
-      missingNames = nub $ filter isExternalName  -- XXX: isExternalName filters out too much
+      missingNames = nubByName id $ filter isExternalName  -- XXX: isExternalName filters out too much
                     (missingNames1 ++ missingNames2 ++ missingNames3
                      ++ missingNames4 ++ missingNames5)
 
@@ -314,6 +314,11 @@ renameInstHead InstHead {..} = do
 renameLDecl :: LHsDecl Name -> RnM (LHsDecl DocName)
 renameLDecl (L loc d) = return . L loc =<< renameDecl d
 
+renamePats :: [(HsDecl Name,DocForDecl Name)] -> RnM [(HsDecl DocName,DocForDecl DocName)]
+renamePats = mapM
+  (\(d,doc) -> do { d'   <- renameDecl d
+                  ; doc' <- renameDocForDecl doc
+                  ; return (d',doc')})
 
 renameDecl :: HsDecl Name -> RnM (HsDecl DocName)
 renameDecl decl = case decl of
@@ -601,15 +606,16 @@ renameExportItem item = case item of
   ExportGroup lev id_ doc -> do
     doc' <- renameDoc doc
     return (ExportGroup lev id_ doc')
-  ExportDecl decl doc subs instances fixities splice -> do
+  ExportDecl decl pats doc subs instances fixities splice -> do
     decl' <- renameLDecl decl
+    pats' <- renamePats pats
     doc'  <- renameDocForDecl doc
     subs' <- mapM renameSub subs
     instances' <- forM instances renameDocInstance
     fixities' <- forM fixities $ \(name, fixity) -> do
       name' <- lookupRn name
       return (name', fixity)
-    return (ExportDecl decl' doc' subs' instances' fixities' splice)
+    return (ExportDecl decl' pats' doc' subs' instances' fixities' splice)
   ExportNoDecl x subs -> do
     x'    <- lookupRn x
     subs' <- mapM lookupRn subs