Benchmark cmpthese() removing '.' char from input param

[stevieb]

While doing a benchmark between a C implementation of some file work to a pure Perl implementation, I found what I think might be an issue in Benchmark cmpthese, whereby it seems to remove a . character from input param to the subs being tested.

Here's an extremely minimalistic version that demonstrates the issue:

use warnings;
use strict;

use Benchmark qw(:all);

my $fname = 'a.txt';

cmpthese( 1, {
    p_read => "p_read($fname)",
});

sub p_read {
    my $fname = shift;
    print "$fname\n";    
}

__END__
atxt
# cmpthese output redacted

This happens with Benchmark v1.12 on perl v5.14.4 and Benchmark v1.2 on perl v5.22.1.

Have I overlooked something in the docs perhaps that anyone knows about?

[dave_the_m]

The code gets evalled, so you need quotes:

    p_read => "p_read('$fname')",

Otherwise you get the bareword 'a' concatenated with the bareword 'txt'.

Dave.

[stevieb]

D'oh! Of course :) Thanks guys!

-stevieb

[1nickt]

Hi stevieb, that's odd!

Same results here on 5.22 and 5.8.8 under darwin. It seems to be an issue with variable interpolation by Benchmark:

use strict; use warnings;
use Benchmark qw(:all);

cmpthese( 1, {
    p_read => "p_read('a.txt')",
});

sub p_read {
    my $fname = shift;
    print "$fname\n";
}

__END__

Output:

a.txt
    ...