Match objects

    sub line-and-column(Match $m) {
        my $line   = ($m.orig.substr(0, $m.from).split("\n")).elems;
        # RAKUDO workaround for RT #70003, $m.orig.rindex(...) directly fails
        my $column = $m.from - ('' ~ $m.orig).rindex("\n", $m.from);
        $line, $column;
    }

    my $s = "the quick\nbrown fox jumped\nover the the lazy dog";

    my token word { \w+ [ \' \w+]? }
    my regex dup { <word> \W+ $<word> }

    if $s ~~ m/ <dup> / {
        my ($line, $column) = line-and-column($/);
        say "Found '{$<dup><word>}' twice in a row";
        say "at line $line, column $column";
    }

    # output:
    # Found 'the' twice in a row
    # at line 3, column 6

Every regex match returns an object of type Match. In boolean context, a match object returns True for successful matches and False for failed ones. Most properties are only interesting after successful matches.

The orig method returns the string that was matched against. The from and to methods return the positions of the start and end points of the match.

In the previous example, the line-and-column function determines the line number in which the match occurred by extracting the string up to the match position ($m.orig.substr(0, $m.from)), splitting it by newlines, and counting the elements. It calculates the column by searching backwards from the match position and calculating the difference to the match position.

Using a match object as an array yields access to the positional captures. Using it as a hash reveals the named captures. In the previous example, $<dup> is a shortcut for $/<dup> or $/{ 'dup' }. These captures are again Match objects, so match objects are really trees of matches.

The caps method returns all captures, named and positional, in the order in which their matched text appears in the source string. The return value is a list of Pair objects, the keys of which are the names or numbers of the capture and the values the corresponding Match objects.

    if 'abc' ~~ m/(.) <alpha> (.) / {
        for $/.caps {
            say .key, ' => ', .value;

        }
    }

    # Output:
    # 0 => a
    # alpha => b
    # 1 => c

In this case the captures occur in the same order as they are in the regex, but quantifiers can change that. Even so, $/.caps follows the ordering of the string, not of the regex. Any parts of the string which match but not as part of captures will not appear in the values that caps returns.

To access the non-captured parts too, use $/.chunks instead. It returns both the captured and the non-captured part of the matched string, in the same format as caps, but with a tilde ~ as key. If there are no overlapping captures (as occurs from look-around assertions), the concatenation of all the pair values that chunks returns is the same as the matched part of the string.