Better identifier parsing

  * '(<|>)' and '`elem`' now get parsed and rendered properly as links
  * 'DbModule'/'DbUnitId' now properly get split apart into two links
  * tuple names now get parsed properly
  * some more small niceties...

The identifier parsing code is more precise and more efficient (although to be
fair: it is also longer and in its own module). On the rendering side, we need
to pipe through information about backticks/parens/neither all the way through
from renaming to the backends.

In terms of impact: a total of 35 modules in the entirety of the bootlib + ghc
lib docs change. The only "regression" is things like '\0'. These should be
changed to @\\0@ (the path by which this previously worked seems accidental).

1 files changed, 12 insertions, 7 deletions

diff --git a/haddock-api/src/Haddock/Parser.hs b/haddock-api/src/Haddock/Parser.hs
index 8b7dda7c..6d5dc103 100644
--- a/haddock-api/src/Haddock/Parser.hs
+++ b/haddock-api/src/Haddock/Parser.hs
@@ -15,27 +15,32 @@ module Haddock.Parser ( parseParas
 
 import qualified Documentation.Haddock.Parser as P
 import Documentation.Haddock.Types
-import Haddock.Types (NsRdrName(..))
+import Haddock.Types
 
 import DynFlags     ( DynFlags )
 import FastString   ( fsLit )
 import Lexer        ( mkPState, unP, ParseResult(POk) )
 import Parser       ( parseIdentifier )
-import RdrName      ( RdrName )
 import SrcLoc       ( mkRealSrcLoc, GenLocated(..) )
 import StringBuffer ( stringToStringBuffer )
 
-parseParas :: DynFlags -> Maybe Package -> String -> MetaDoc mod NsRdrName
+
+parseParas :: DynFlags -> Maybe Package -> String -> MetaDoc mod (Wrap NsRdrName)
 parseParas d p = overDoc (P.overIdentifier (parseIdent d)) . P.parseParas p
 
-parseString :: DynFlags -> String -> DocH mod NsRdrName
+parseString :: DynFlags -> String -> DocH mod (Wrap NsRdrName)
 parseString d = P.overIdentifier (parseIdent d) . P.parseString
 
-parseIdent :: DynFlags -> Namespace -> String -> Maybe NsRdrName
+parseIdent :: DynFlags -> Namespace -> String -> Maybe (Wrap NsRdrName)
 parseIdent dflags ns str0 =
-  let buffer = stringToStringBuffer str0
+  let buffer = stringToStringBuffer str1
       realSrcLc = mkRealSrcLoc (fsLit "<unknown file>") 0 0
       pstate = mkPState dflags buffer realSrcLc
+      (wrap,str1) = case str0 of
+                      '(' : s@(c : _) | c /= ',', c /= ')'  -- rule out tuple names
+                                      -> (Parenthesized, init s)
+                      '`' : s@(_ : _) -> (Backticked,    init s)
+                      _               -> (Unadorned,     str0)
   in case unP parseIdentifier pstate of
-    POk _ (L _ name) -> Just (NsRdrName ns name)
+    POk _ (L _ name) -> Just (wrap (NsRdrName ns name))
     _ -> Nothing