12.10. Named Characters

Prefer named characters to escaped metacharacters.

As an alternative to the previous guideline, Perl 5.6 (and later) supports named characters in regexes. As previously discussed^[*], this mechanism is much better for "unprintable" components of a regex. For example, instead of:

^[*] "Escaped Characters" in Chapter 4.

    if ($escape_seq =~ /\177 \006 \030 Z/xms) {   # Octal DEL-ACK-CAN-Z
        blink(182);
    }

use:

    use charnames qw( :full );

    if ($escape_seq =~ m/\N{DELETE} \N{ACKNOWLEDGE} \N{CANCEL} Z/xms) {
        blink(182);
    }

Note, however that named whitespace characters are treated like ordinary whitespace (i.e., they're ignored) under the /x flag:

    use charnames qw( :full );

    # and later...

    $name =~ m{ harry \N{SPACE} s \N{SPACE} truman     # harrystruman
              | harry \N{SPACE} j \N{SPACE} potter     # harryjpotter
              }ixms;

You would still need to put them in characters classes to make them match:

    use charnames qw( :full );

    
# and later...

    $name =~ m{ harry [\N{SPACE}] s [\N{SPACE}] truman     
# harry s truman
              | harry [\N{SPACE}] j [\N{SPACE}] potter     
# harry j potter
              }ixms;