Re^2: how to measure strictness of a regex ?

I, also, have some (admittedly, rather idle) curiosity: what is the purpose of the prototype in the re_strictness() function definition?

Comment on Re^2: how to measure strictness of a regex ? Download Code

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Re^3: how to measure strictness of a regex ? by tobyink (Canon) on Jan 23, 2013 at 07:47 UTC
I think my original code when I was testing was something along the lines of: `print re_strictness qr/.../, "\n";` [download] In which case the `($)` prototype helps Perl see the `"\n"` as a parameter for `print`, not for `re_strictness`. By the way, it's worth pointing out that `qr/^Dad+y$/` is also considered slightly stricter than `qr/Dad+y/`. `use 5.014; use strict; use warnings; use re (); use List::Util 'sum'; sub re_strictness ($) { sum map length, re::regmust shift } print re_strictness qr/^Dad+y$/, "\n", re_strictness qr/Dad+y/, "\n", re_strictness qr/D.+/, "\n", ;` [download] `package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name`	[reply] [d/l] [select]

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Re^3: how to measure strictness of a regex ?
by tobyink (Canon) on Jan 23, 2013 at 07:47 UTC

I think my original code when I was testing was something along the lines of:

print re_strictness qr/.../, "\n";
[download]

In which case the ($) prototype helps Perl see the "\n" as a parameter for print, not for re_strictness.

By the way, it's worth pointing out that qr/^Dad+y$/ is also considered slightly stricter than qr/Dad+y/.

use 5.014;
use strict;
use warnings;
use re ();
use List::Util 'sum';

sub re_strictness ($) { sum map length, re::regmust shift }

print
    re_strictness qr/^Dad+y$/, "\n",
    re_strictness qr/Dad+y/, "\n",
    re_strictness qr/D.+/, "\n",
;
[download]

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

[reply]
[d/l]
[select]