Hi all,
I'm using the Parsec library to parse the following grammar
expr = atom+
atom = integer | var | (expr)
The input to the parser is a list of (Token, SourcePos). I have the
following code for atom:
atom
= try variable <|> try integerr <|>
do{sat(== Reserved "("); (e,pos) <- expression; sat(==Reserved
")"); return (e,pos)}
sat p = do (t,pos) <- item
if p t then return(t,pos) else pzero
When I run the code on the input "(_ineg_ 0)" the parser fails, but
removing
sat(==Reserved ")")
and it succeeds. Can any one see why?
E.
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