[haddock @ 2002-05-15 13:03:01 by simonmar]

Reworking of the internals to support documenting function arguments
(the Most Wanted new feature by the punters).

The old method of keeping parsed documentation in a Name -> Doc
mapping wasn't going to cut it for anntations on type components,
where there's no name to attach the documentation to, so I've moved to
storing all the documentation in the abstract syntax.  Previously some
of the documentation was left in the abstract syntax by the parser,
but was later extracted into the mapping.

In order to avoid having to parameterise the abstract syntax over the
type of documentation stored in it, we have to parse the documentation
at the same time as we parse the Haskell source (well, I suppose we
could store 'Either String Doc' in the HsSyn, but that's clunky).  One
upshot is that documentation is now parsed eagerly, and documentation
parse errors are fatal (but have better line numbers in the error
message).

The new story simplifies matters for the code that processes the
source modules, because we don't have to maintain the extra Name->Doc
mapping, and it should improve efficiency a little too.

New features:

  - Function arguments and return values can now have doc annotations.

  - If you refer to a qualified name in a doc string, eg. 'IO.putStr',
    then Haddock will emit a hyperlink even if the identifier is not
    in scope, so you don't have to make sure everything referred to
    from the documentation is imported.

  - several bugs & minor infelicities fixed.

1 files changed, 27 insertions, 20 deletions

diff --git a/src/HsLexer.lhs b/src/HsLexer.lhs
index 505e07f8..c6026b67 100644
--- a/src/HsLexer.lhs
+++ b/src/HsLexer.lhs
@@ -1,5 +1,5 @@
 -----------------------------------------------------------------------------
--- $Id: HsLexer.lhs,v 1.8 2002/05/09 12:45:19 simonmar Exp $
+-- $Id: HsLexer.lhs,v 1.9 2002/05/15 13:03:02 simonmar Exp $
 --
 -- (c) The GHC Team, 1997-2000
 --
@@ -17,7 +17,7 @@ module HsLexer (Token(..), lexer, parseError,isSymbol) where
 
 import HsParseMonad
 import HsParseUtils
-import HsSyn(SrcLoc(..))
+import HsSyn
 
 import Numeric	( readHex, readOct )
 import Char
@@ -64,11 +64,11 @@ data Token
 	
 -- Documentation annotations
 
-	| DocCommentNext String		-- something beginning '-- |'
-	| DocCommentPrev String		-- something beginning '-- ^'
+	| DocCommentNext  String	-- something beginning '-- |'
+	| DocCommentPrev  String	-- something beginning '-- ^'
 	| DocCommentNamed String	-- something beginning '-- $'
-	| DocSection Int String		-- a section heading
-	| DocOptions String
+	| DocSection      Int String	-- a section heading
+	| DocOptions      String	-- attributes '-- #'
 
 -- Reserved operators
 
@@ -280,10 +280,9 @@ lexToken cont s loc y x =
    -- trace ("lexer: y="++show y++" x="++show x++"\n") $ 
    case s of
 	-- First the doc comments
-	'-':'-':' ':s -> do_doc s docComment
-
-	'{':'-':' ':s -> do_doc s nestedDocComment
-	'{':'-':s     -> do_doc s nestedDocComment
+	'-':'-':' ':s -> do_doc s False
+	'{':'-':' ':s -> do_doc s True
+	'{':'-':s     -> do_doc s True
 
         -- Next the special symbols
         '(':'#':s -> forward 2 LeftUT s
@@ -346,16 +345,21 @@ lexToken cont s loc y x =
 
   where forward n t s = cont t s loc y (x+n)
 
-	do_doc ('|':s) f = f DocCommentNext  cont s loc y x
-	do_doc ('/':s) f = f DocCommentNext  cont s loc y x
-	do_doc ('^':s) f = f DocCommentPrev  cont s loc y x
-	do_doc ('$':s) f = f DocCommentNamed cont s loc y x
-	do_doc ('#':s) f = f DocOptions      cont s loc y x
-	do_doc ('*':s) f = section 1 s
+	-- this is all terribly ugly, sorry :(
+	do_doc ('|':s) nested  = multi nested DocCommentNext  cont s loc y x
+	do_doc ('/':s) nested  = multi nested DocCommentNext  cont s loc y x
+	do_doc ('^':s) nested  = multi nested DocCommentPrev  cont s loc y x
+	do_doc ('$':s) nested  = multi nested DocCommentNamed cont s loc y x
+	do_doc ('#':s) nested  = multi nested DocOptions      cont s loc y x
+	do_doc ('*':s) nested  = section 1 s
 	  where section n ('*':s) = section (n+1) s
-		section n s = f (DocSection n) cont s loc y x
+		section n s 
+		  | nested = nestedDocComment (DocSection n) cont s loc y x
+		  | otherwise = oneLineDocComment (DocSection n) cont s loc y x
 	do_doc _ _ = error "Internal error: HsLexer.do_doc"
 
+multi True  = nestedDocComment
+multi False = multiLineDocComment
 
 afterNum cont i ('#':s) loc y x = cont (PrimInt i) s loc y (x+1)
 afterNum cont i s loc y x = cont (IntTok i) s loc y x
@@ -593,10 +597,13 @@ nestedDocComment f cont s loc y x = go f cont "" y x s
       c:s       -> go f cont (c:acc) y (x+1) s
       []        -> error "Internal error: nestedComment"
 
+oneLineDocComment f cont s loc y x
+  = cont (f line) rest loc y x -- continue with the newline char
+  where (line, rest) = break (== '\n') s
 
-docComment f cont s loc y x 
-  = let (s', comment, y') = slurpExtraCommentLines s [] y in
-    cont (f comment) s' loc y' x  -- continue with the newline char
+multiLineDocComment f cont s loc y x 
+  = cont (f comment) s' loc y' x -- continue with the newline char
+  where (s', comment, y') = slurpExtraCommentLines s [] y
     
 slurpExtraCommentLines s lines y
   = case rest of