in reply to JAVA [[a-z]&&[^aeiou]] equivalence

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11160494
use warnings;
$SIG{__WARN__} = sub { die @_ };

my @match = grep /(?=[^aeiou])[a-z]/, map chr, 0 .. 255;
print "match = @match\n";

[download]

Outputs: 

match = b c d f g h j k l m n p q r s t v w x y z

[download]

Replies are listed 'Best First'.
Re^2: JAVA [[a-z]&&[^aeiou]] equivalence
by vincentaxhe (Scribe) on Jul 10, 2024 at 06:48 UTC
    it's a good approach,seems informal, I wonder is there a better way.
[reply]

      Perl is intentionally informal. This is one of its greatest strengths.

      🦛

[reply]
        Regexes are a DSL available as sub language in many languages, and I'm confident most allow using lookahead assertions for and-combining regexes. Even in Java.

        So it's not an exclusive Perl thing.

        See this JS doc for instance:

        Lookahead_assertion#pattern_subtraction_and_intersection¹

        It's also worth discussing the pro and cons of the regex-sets solution posted by choroba.

        The lookaheads are generic and not restricted to character classes and allow combining any kind of patterns.

        But in the case of handling character classes only, I expect the regex-class solution to be faster and better readable.

        Cheers Rolf
        (addicted to the Perl Programming Language :)
        see Wikisyntax for the Monastery

        ¹) Using lookahead, you can match a string multiple times with different patterns, which allows you to express complex relationships like subtraction (is X but not Y) and intersection (is both X and Y).

[reply]
      A reply falls below the community's threshold of quality. You may see it by logging in.

In Section Seekers of Perl Wisdom