On Fri, Jan 20, 2017 at 04:57:51PM +0100, Tudor Girba wrote: > Hi, > > When you have questions like these, you can also use the built-in debugging > facilities. For example, in your case, you can see that the #any parser > consumed everything like this:
Ah, thanks. I was looking for this in the debugger (because I remember there was some extension related to PetitParser) and completely missed it in the playground. > >> Am 20.01.2017 um 15:24 schrieb Peter Uhnak <i.uh...@gmail.com>: > >> > >> Is PetitParser eager by default? > >> > >> I've used PetitParser countless times so I am really baffled why this > >> doesn't work > >> > >> str := 'a0b'. > >> #any asParser star, #digit asParser, #any asParser star parse: str. > >> > >> -> PPFailure (input expected at: 3) > >> > > > > PetitParser is not greedy per default. But back tracking only works if a > > parser fails. Using , creates a sequence of combined parsers. If one fails > > the whole sequence fails. As a star parser always succeeds it would be huge > > luck if your rule would succeed. The probability that the parser consumes > > exactly one character is not high. Maybe negating the first sequence part > > is what you want This is not just about one character. s := 'hello 123 world'. #any asParser star , #digit asParser plus , #any asParser star parse: s. But from your explanation my understanding is that this is actually not possible with #any. Basically I was looking for the PetitParser equivalent of .*?\d+.* regex (note that even in greedy form the regex wouldn't fail because it would leave the last digit for \d) Peter
