#!perl -w

use strict;

use Benchmark qw/cmpthese/;

my %tran_types;
foreach ('A'..'Z') { $tran_types{$_} = "" };

my $char_y = 'J';       # yes
my $char_n = '_';       # no
my $char_n_l = 'AA';    # no; too long
my $char_n_A = '0';     # no; lt 'A'
my $char_n_Z = 'a';     # no; gt 'Z'

cmpthese(-(shift), {
    're_Y'  => sub { $char_y =~ /^[A-Z]\z/ },
    're_n'  => sub { $char_n =~ /^[A-Z]\z/ },
    'co_Y'  => sub { length $char_y == 1 and
                       $char_y ge "A" and $char_y le "Z" },
    'co_nA' => sub { length $char_n_A == 1 and
                       $char_n_A ge "A" and $char_n_A le "Z" },
    'co_nZ' => sub { length $char_n_Z == 1 and
                       $char_n_Z ge "A" and $char_n_Z le "Z" },
    'co_nl' => sub { length $char_n_l == 1 and
                       $char_n_l ge "A" and $char_n_l le "Z" },
    'ex_Y'  => sub { exists $tran_types{$char_y} },
    'ex_n'  => sub { exists $tran_types{$char_n} },
});


##</code><code>##

Benchmark: running co_Y, co_nA, co_nZ, co_nl, ex_Y, ex_n, re_Y, re_n, each for at least 15 CPU seconds...
      co_Y: 18 wallclock secs (14.95 usr +  0.05 sys = 15.00 CPU) @ 266935.00/s (n=4004025)
     co_nA: 15 wallclock secs (15.63 usr + -0.03 sys = 15.60 CPU) @ 355186.35/s (n=5540907)
     co_nZ: 18 wallclock secs (15.71 usr +  0.10 sys = 15.81 CPU) @ 262582.80/s (n=4151434)
     co_nl: 17 wallclock secs (16.12 usr + -0.09 sys = 16.03 CPU) @ 720797.75/s (n=11554388)
      ex_Y: 14 wallclock secs (16.11 usr + -0.02 sys = 16.09 CPU) @ 712203.05/s (n=11459347)
      ex_n: 14 wallclock secs (16.72 usr + -0.62 sys = 16.10 CPU) @ 862264.35/s (n=13882456)
      re_Y: 16 wallclock secs (15.18 usr +  0.12 sys = 15.30 CPU) @ 202467.06/s (n=3097746)
      re_n: 17 wallclock secs (15.97 usr + -0.02 sys = 15.95 CPU) @ 243489.40/s (n=3883656)
          Rate  re_Y  re_n co_nZ  co_Y co_nA  ex_Y co_nl  ex_n
re_Y  202467/s    --  -17%  -23%  -24%  -43%  -72%  -72%  -77%
re_n  243489/s   20%    --   -7%   -9%  -31%  -66%  -66%  -72%
co_nZ 262583/s   30%    8%    --   -2%  -26%  -63%  -64%  -70%
co_Y  266935/s   32%   10%    2%    --  -25%  -63%  -63%  -69%
co_nA 355186/s   75%   46%   35%   33%    --  -50%  -51%  -59%
ex_Y  712203/s  252%  192%  171%  167%  101%    --   -1%  -17%
co_nl 720798/s  256%  196%  175%  170%  103%    1%    --  -16%
ex_n  862264/s  326%  254%  228%  223%  143%   21%   20%    --