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authorsimonmar <unknown>2002-04-04 16:23:43 +0000
committersimonmar <unknown>2002-04-04 16:23:43 +0000
commit2b39cd941c80d2603f2480684c45dd31f9256831 (patch)
tree87a4fdb2752c8a99e54e50e45c1bfa8c2bf80577 /src/HsParseMonad.lhs
[haddock @ 2002-04-04 16:23:43 by simonmar]
This is Haddock, my stab at a Haskell documentation tool. It's not quite ready for release yet, but I'm putting it in the repository so others can take a look. It uses a locally modified version of the hssource parser, extended with support for GHC extensions and documentation annotations.
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+-----------------------------------------------------------------------------
+-- $Id: HsParseMonad.lhs,v 1.1 2002/04/04 16:23:43 simonmar Exp $
+--
+-- (c) The GHC Team 1997-2000
+--
+-- Monad for the Haskell parser.
+--
+-----------------------------------------------------------------------------
+
+\begin{code}
+module HsParseMonad where
+
+import HsSyn
+\end{code}
+
+\begin{code}
+data ParseResult a = Ok ParseState a | Failed String
+ deriving Show
+
+data LexContext = NoLayout | Layout Int
+ deriving (Eq,Ord,Show)
+
+type ParseState = [LexContext]
+
+type P a
+ = String -- input string
+ -> SrcLoc -- location of last token read
+ -> Int -- current line
+ -> Int -- current column
+ -> ParseState -- layout info.
+ -> ParseResult a
+
+thenP :: P a -> (a -> P b) -> P b
+m `thenP` k = \i l n c s ->
+ case m i l n c s of
+ Failed s -> Failed s
+ Ok s' a -> case k a of k' -> k' i l n c s'
+
+m `thenP_` k = m `thenP` \_ -> k
+
+mapP :: (a -> P b) -> [a] -> P [b]
+mapP f [] = returnP []
+mapP f (a:as) =
+ f a `thenP` \b ->
+ mapP f as `thenP` \bs ->
+ returnP (b:bs)
+
+returnP a = \i l n c s -> Ok s a
+
+failP :: String -> P a
+failP err = \i l n c s -> Failed err
+
+getSrcLoc :: P SrcLoc
+getSrcLoc = \i l n c s -> Ok s l
+
+getContext :: P [LexContext]
+getContext = \i l n c s -> Ok s s
+
+pushContext :: LexContext -> P ()
+pushContext ctxt =
+--trace ("pushing lexical scope: " ++ show ctxt ++"\n") $
+ \i l n c s -> Ok (ctxt:s) ()
+
+popContext :: P ()
+popContext = \i l n c stk ->
+ case stk of
+ (_:s) -> --trace ("popping lexical scope, context now "++show s ++ "\n") $
+ Ok s ()
+ [] -> error "Internal error: empty context in popContext"
+\end{code}