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

stevieb has asked for the wisdom of the Perl Monks concerning the following question:

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
[download]

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?

Comment on Benchmark cmpthese() removing '.' char from input param Select or Download Code

Replies are listed 'Best First'.
Re: Benchmark cmpthese() removing '.' char from input param by dave_the_m (Monsignor) on Mar 12, 2016 at 16:10 UTC
The code gets evalled, so you need quotes: `p_read => "p_read('$fname')",` [download] Otherwise you get the bareword 'a' concatenated with the bareword 'txt'. Dave.	[reply] [d/l]
Re^2: Benchmark cmpthese() removing '.' char from input param by stevieb (Canon) on Mar 12, 2016 at 16:16 UTC
D'oh! Of course :) Thanks guys! -stevieb	[reply]
Re: Benchmark cmpthese() removing '.' char from input param by 1nickt (Canon) on Mar 12, 2016 at 16:07 UTC
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__` [download] Output: `a.txt ...` [download] The way forward always starts with a minimal test.	[reply] [d/l] [select]

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