[haddock @ 2002-05-29 13:19:06 by simonmar]

Make the markup syntax a little more friendly:

  - single quotes are now interpreted literally unless they surround a
    valid Haskell identifier.  So for example now there's no need to
    escape a single quote used as an apostrophe.

  - text to the right of a bird track is now literal (if you want
    marked-up text in a code block, use @...@).

1 files changed, 69 insertions, 29 deletions

diff --git a/src/HaddockLex.hs b/src/HaddockLex.hs
index f766222d..000d62f0 100644
--- a/src/HaddockLex.hs
+++ b/src/HaddockLex.hs
@@ -10,19 +10,25 @@ module HaddockLex (
  ) where
 
 import Char
-
-special = '`' : '\'' : '\"' : '@' : '/' : []
+import HsSyn
+import HsLexer hiding (Token)
+import HsParseMonad
 
 data Token
   = TokPara
   | TokNumber
   | TokBullet
   | TokSpecial Char
+  | TokIdent [HsQName]
   | TokString String
   | TokURL String
   | TokBirdTrack
   deriving Show
 
+isSpecial c     = c `elem` ['\"', '@', '/']
+isSingleQuote c = c `elem` ['\'', '`']
+isIdent c       = isAlphaNum c || c == '_'
+
 -- simple finite-state machine for tokenising the doc string
 
 -- ----------------------------------------------------------------------------
@@ -32,14 +38,15 @@ tokenise :: String -> [Token]
 tokenise "" = []
 tokenise str = case str of
   '<':cs  -> tokenise_url cs
-  '\n':cs -> tokenise_newline tokenise cs
-  c:cs | c `elem` special -> TokSpecial c : tokenise cs
+  '\n':cs -> tokenise_newline cs
+  c:cs 	| isSingleQuote c -> tokenise_identifier c cs
+	| isSpecial c     -> TokSpecial c : tokenise1 cs
   _other  -> tokenise_string "" str
 
-tokenise_newline next cs =
+tokenise_newline cs =
  case dropWhile nonNewlineSpace cs of
    '\n':cs -> TokPara : tokenise_para cs -- paragraph break
-   '>':cs  -> TokBirdTrack : next cs -- bird track
+   '>':cs  -> TokBirdTrack : tokenise_birdtrack cs -- bird track
    _other  -> tokenise_string "" cs
 
 tokenise_para cs =
@@ -49,7 +56,7 @@ tokenise_para cs =
 	-- bullet: '-'
    '-':cs  -> TokBullet  : tokenise cs
 	-- enumerated item: '1.'
-   '>':cs  -> TokBirdTrack : tokenise cs
+   '>':cs  -> TokBirdTrack : tokenise_birdtrack cs
 	-- bird track
    str | (ds,'.':cs) <- span isDigit str, not (null ds)
 		-> TokNumber : tokenise cs
@@ -65,18 +72,14 @@ nonNewlineSpace c = isSpace c && c /= '\n'
 -- birdtrack, and before a paragraph break).
 
 tokenise1 :: String -> [Token]
-tokenise1 "" = []
-tokenise1 str = case str of
-  '<':cs  -> tokenise_url cs
-  '\n':cs -> tokenise_newline1 cs
-  c:cs | c `elem` special -> TokSpecial c : tokenise1 cs
-  _other  -> tokenise_string "" str
+tokenise1 str = tokenise_string "" str
 
-tokenise_newline1 cs =
- case dropWhile nonNewlineSpace cs of
-   '\n':cs -> TokPara : tokenise_para cs -- paragraph break
-   '>':cs  -> TokString "\n" : TokBirdTrack : tokenise1 cs -- bird track
-   _other  -> tokenise_string "\n" cs
+-- found a single quote, check whether we have an identifier...
+tokenise_identifier q cs =
+  let (ident,rest) = break (not.isIdent) cs in
+  case (rest, strToHsQNames ident) of
+    (c:cs, Just names) | isSingleQuote c -> TokIdent names : tokenise1 cs
+    _other -> tokenise_string [q] cs
 
 tokenise_url cs =
   let (url,rest) = break (=='>') cs in
@@ -84,21 +87,58 @@ tokenise_url cs =
 		 '>':rest -> tokenise1 rest
 		 _ -> tokenise1 rest
 
--- ----------------------------------------------------------------------------
--- Within a string, we don't throw away any whitespace
-
 tokenise_string str cs = 
   case cs of
-    [] -> [TokString (reverse str)]
+    []        -> tokString str []
     '\\':c:cs -> tokenise_string (c:str) cs
     '\n':cs   -> tokenise_string_newline str cs
-    '<':cs    -> TokString (reverse str) : tokenise_url cs
-    c:cs | c `elem` special -> TokString (reverse str) : tokenise1 (c:cs)
-         | otherwise 	    -> tokenise_string (c:str) cs
+    '<':cs    -> tokString str (tokenise_url cs)
+    c:cs | isSpecial c     -> tokString str (TokSpecial c : tokenise1 cs)
+	 | isSingleQuote c -> tokString str (tokenise_identifier c cs)
+         | otherwise 	   -> tokenise_string (c:str) cs
 
 tokenise_string_newline str cs =
   case dropWhile nonNewlineSpace cs  of
-   '\n':cs -> TokString (reverse str) : TokPara : tokenise_para cs
-   '>':cs  -> TokString (reverse ('\n':str)) : TokBirdTrack : tokenise1 cs
-		 -- bird track
-   _other  -> tokenise_string ('\n':str) cs  -- don't throw away whitespace
+   '\n':cs -> tokString str (TokPara : tokenise_para cs)
+		-- paragraph break: throw away all whitespace
+   '>':cs  -> tokString ('\n':str) (TokBirdTrack : tokenise_birdtrack cs)
+		-- keep the \n, but throw away any space before the '>'
+   _other  -> tokenise_string ('\n':str) cs
+		-- don't throw away whitespace at all
+
+tokString [] rest = rest
+tokString cs rest = TokString (reverse cs) : rest
+
+-- A bird-tracked line is verbatim, no markup characters are interpreted
+tokenise_birdtrack cs = 
+  let (line, rest) = break (=='\n') cs in
+  TokString line : tokenise1 rest
+
+-- -----------------------------------------------------------------------------
+-- Lex a string as a Haskell identifier
+
+strToHsQNames :: String -> Maybe [HsQName]
+strToHsQNames str
+ = case lexer (\t -> returnP t) str (SrcLoc 1 1) 1 1 [] of
+	Ok _ (VarId str)
+	   -> Just [ UnQual (HsVarName (HsIdent str)) ]
+        Ok _ (QVarId (mod,str))
+ 	   -> Just [ Qual (Module mod) (HsVarName (HsIdent str)) ]
+	Ok _ (ConId str)
+	   -> Just [ UnQual (HsTyClsName (HsIdent str)),
+		     UnQual (HsVarName (HsIdent str)) ]
+        Ok _ (QConId (mod,str))
+	   -> Just [ Qual (Module mod) (HsTyClsName (HsIdent str)),
+		     Qual (Module mod) (HsVarName (HsIdent str)) ]
+        Ok _ (VarSym str)
+	   -> Just [ UnQual (HsVarName (HsSymbol str)) ]
+        Ok _ (ConSym str)
+	   -> Just [ UnQual (HsTyClsName (HsSymbol str)),
+		     UnQual (HsVarName (HsSymbol str)) ]
+        Ok _ (QVarSym (mod,str))
+	   -> Just [ Qual (Module mod) (HsVarName (HsSymbol str)) ]
+        Ok _ (QConSym (mod,str))
+	   -> Just [ Qual (Module mod) (HsTyClsName (HsSymbol str)),
+		     Qual (Module mod) (HsVarName (HsSymbol str)) ]
+	other
+	   -> Nothing