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author | simonmar <unknown> | 2002-04-04 16:23:43 +0000 |
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committer | simonmar <unknown> | 2002-04-04 16:23:43 +0000 |
commit | 2b39cd941c80d2603f2480684c45dd31f9256831 (patch) | |
tree | 87a4fdb2752c8a99e54e50e45c1bfa8c2bf80577 /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.
Diffstat (limited to 'src/HsParseMonad.lhs')
-rw-r--r-- | src/HsParseMonad.lhs | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/src/HsParseMonad.lhs b/src/HsParseMonad.lhs new file mode 100644 index 00000000..af29dd80 --- /dev/null +++ b/src/HsParseMonad.lhs @@ -0,0 +1,70 @@ +----------------------------------------------------------------------------- +-- $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} |