Re: Quiz question on string matching

[Philipp Janda <siffiejoe@...>]

Am 29.01.2016 um 06:50 schröbte Paul K:
> > Find a pattern with no captures such that putting it in parentheses may change what it matches.
>
> testanswer("abc", "^.")
> testanswer("abc", ".$")

testanswer("abc", "")

> Paul.

Philipp

> On Thu, Jan 28, 2016 at 9:41 PM, Dirk Laurie <dirk.laurie@gmail.com> wrote:
> >    Find a pattern with no captures such that putting it in parentheses
> >    may change what it matches.
> >
> > More precisely:
> >
> >     Find strings `str` and `pat` such that `testanswer(str,pat)` prints
> >     'true', where
> >
> > testanswer = function(str,pat)
> > if pat:match"[()]" then return end
> > print(str:match(pat) ~= str:match('(' .. pat .. ')'))
> > end