[Moose-dev] Re: PetitParser, longest match

On 26 July 2010 17:48, Alberto Bacchelli alberto.bacchelli@usi.ch wrote:

Another fast question :) :

since the "not" method parses p and succeeds when it fails, but does not consume its input. What is the best way to define something negated? For example to define:

"everything but a word or a space"

If

wordOrSpace := #word asParser / #space asParser.

is given you can write the negation using the helper #negate like

wordOrSpace negate

which simply consumes one character if the receiver does not parse:

wordOrSpace not , #any asParser ==> #second

Lukas