> The "implicit" alternation comes from interpolating a list (of subrules, > see below).
I see. And that's discussed here (had to really look for it): https://docs.perl6.org/language/regexes#Quoted_lists_are_LTM_matches At first I was looking further down in the "Regex interpolation" section, where it's also touched on, though I kept missing it: > When an array variable is interpolated into a regex, the regex engine handles > it like a | alternative of the regex elements (see the documentation on > embedded lists, above). On 9/1/19, The Sidhekin <sidhe...@gmail.com> wrote: > On Mon, Sep 2, 2019 at 1:12 AM Joseph Brenner <doom...@gmail.com> wrote: > >> I was just trying to run Simon Proctor's solution, and I see it >> working for Yary's first case, but not his more complex one with >> problem characters like brackets included in the list of characters. >> >> I don't really see how to fix it, in part because I'm not that >> clear on what it's actually doing... there's some sort of >> implicit alternation going on? >> >> >> sub contains( Str $chars, Str $_ ) { >> m:g/<{$chars.comb}>+/ >> }; >> > > The "implicit" alternation comes from interpolating a list (of subrules, > see below). > > That works for this case: >> >> say contains('24680', '19584203'); >> # (｢8420｣) >> >> But on something like this it errors out: >> >> say contains('+\/\]\[', 'Apple ][+//e'); # says ][+// >> > > … because it's trying to compile each (1-character) string as a subrule … > > To have the (1-character) strings used a literals, rather than compiled > as subrules, put them in an array instead of a block wrapped in angle > brackets: > > sub contains( Str $chars, Str $_ ) { > my @arr = $chars.comb; > m:g/@arr+/ > } > > > (… hey, is there a word for "block wrapped in angle brackets"?) > > > Eirik >
