CODEWITHSUNDEEP
raku
Eugene Barsky
Eugene Barsky

Reputation: 6002

Combining regexes using a loop in Perl 6

Here I make a regex manually from Regex elements of an array. 

my Regex @reg =
  / foo /,
  / bar /,
  / baz /,
  / pun /
  ;

my $r0 = @reg[0];
my $r1 = @reg[1];

my Regex $r = / 0 $r0 | 1 $r1 /;

"0foo_1barz" ~~ m:g/<$r>/;
say $/;  # (｢0foo｣ ｢1bar｣)

How to do it with for @reg {...}?

Upvotes: 2

Views: 171

Answers (2)

moritz
moritz

Reputation: 12842

If a variable contains a regex, you can use it without further ado inside another regex.

The second trick is to use an array variable inside a regex, which is equivalent to the disjunction of the array elements:

my @reg =
  /foo/,
  /bar/,
  /baz/,
  /pun/
  ;

my @transformed = @reg.kv.map(-> $i, $rx { rx/ $i $rx /});

my @match =  "0foo_1barz" ~~ m:g/ @transformed /;

.say for @match;

Upvotes: 6

Holli
Holli

Reputation: 5072

my @reg =
  /foo/,
  /bar/,
  /baz/,
  /pun/
  ;

my $i = 0;

my $reg = @reg
  .map({ $_ = .perl; $_.substr(1, $_.chars - 2); })
  .map({ "{$i++}{$_}" })
  .join('|');

my @match = "foo", "0foo_1barz" ~~ m:g/(<{$reg}>) /;

say @match[1][0].Str;
say @match[1][1].Str;

# 0foo
# 2baz

See the docs

Edit: Actually read the docs myself. Changed implicit eval to $() construct.

Edit: Rewrote answer to something that actually works

Edit: Changed answer to a terrible, terrible hack

Upvotes: 3

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