[Haskell-cafe] An irritating Parsec problem
jonathanccast at fastmail.fm
Wed Oct 15 15:20:39 EDT 2008
On Wed, 2008-10-15 at 20:22 +0100, Andrew Coppin wrote:
> I like Parsec. I use it for everything. But it does have one irritating
> Consider the following parser:
> expressions = many1 expression
> Suppose this is the top-level parser for my language.
I always wrap my top-level parsers in
return const `ap` parser `ap` eof
to express that they have to match the entire input. (This is a bit
easier if you supply the missing Applicative instance:
const <$> parser <*> eof
). I think Parsec should either do this itself or tell you what the
un-consumed input tokens were, but it doesn't.
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