benchmark of building place holder

build_placeholder.pl

#!/usr/bin/env perl
use strict;
use warnings;
use Benchmarks sub {

    my @list = (1..10);

    +{
        map_join => sub {
            join(',', map { '?' } @list);
        },
        x_join => sub {
            join(',', ('?') x scalar(@list));
        },
        x => sub {
            '?,' x (scalar(@list) - 1). '?';
        },
    };
};

=pod

    1..10
    Benchmark: running map_join, x, x_join for at least 1 CPU seconds...
      map_join: 1.04042 wallclock secs ( 1.04 usr +  0.00 sys =  1.04 CPU) @ 220552.88/s (n=229375)
             x: 1.05466 wallclock secs ( 1.05 usr +  0.00 sys =  1.05 CPU) @ 1638399.05/s (n=1720319)
        x_join: 1.03598 wallclock secs ( 1.03 usr +  0.00 sys =  1.03 CPU) @ 477202.91/s (n=491519)
                  Rate map_join   x_join        x
    map_join  220553/s       --     -54%     -87%
    x_join    477203/s     116%       --     -71%
    x        1638399/s     643%     243%       --

    1..100
    Benchmark: running map_join, x, x_join for at least 1 CPU seconds...
      map_join: 1.05057 wallclock secs ( 1.05 usr +  0.00 sys =  1.05 CPU) @ 21557.14/s (n=22635)
             x: 1.05918 wallclock secs ( 1.06 usr +  0.00 sys =  1.06 CPU) @ 865569.81/s (n=917504)
        x_join: 1.07109 wallclock secs ( 1.07 usr +  0.00 sys =  1.07 CPU) @ 53591.59/s (n=57343)
                 Rate map_join   x_join        x
    map_join  21557/s       --     -60%     -98%
    x_join    53592/s     149%       --     -94%
    x        865570/s    3915%    1515%       --
    
    1..1000
    Benchmark: running map_join, x, x_join for at least 1 CPU seconds...
      map_join: 1.11826 wallclock secs ( 1.11 usr +  0.00 sys =  1.11 CPU) @ 2200.90/s (n=2443)
             x: 1.04846 wallclock secs ( 1.05 usr +  0.00 sys =  1.05 CPU) @ 148944.76/s (n=156392)
        x_join: 1.09108 wallclock secs ( 1.09 usr +  0.00 sys =  1.09 CPU) @ 5479.82/s (n=5973)
                 Rate map_join   x_join        x
    map_join   2201/s       --     -60%     -99%
    x_join     5480/s     149%       --     -96%
    x        148945/s    6667%    2618%       --

=cut