Re: Being more Assert-ive with Perl

You might like to look at Carp::Assert. Its assert function is liable to be slower than your test or die constructs, and it doesn't allow you to customize your die statements (unless you use its longer affirm routine, which is bound to be substantially slower.) I find it nice and readable, though. If I have time, I'll benchmark it later.

An idea you might like to steal from it is to append if DEBUG to your assertions, where DEBUG is a constant that you can set to 1 in development/testing and to 0 in production. That way, you have all of the benefits of assertions in development, and none of the overhead in production (along with none of the benefits.)

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Re^2: Being more Assert-ive with Perl
by stvn (Monsignor) on Sep 18, 2004 at 15:58 UTC

If I have time, I'll benchmark it later.

I was already benchmarking for the other responses, so I did it for you.

Here is the code

#!/usr/bin/perl

use strict;
use warnings;

use Benchmark qw(:all);
use Carp::Assert;

sub CarpAssert {
    my ($test) = @_;
    assert($test < 50) if DEBUG;
    return $test;
}

sub OrAssert {
    my ($test) = @_;
    ($test < 50) || die "Test is wrong";
    return $test;
}

my @nums = map { ((rand() * 100) % 50) } (0 .. 100);

cmpthese(10_000, {    
    'CarpAssert' => sub { eval { CarpAssert($_) } for (@nums) },    
    'OrAssert'   => sub { eval { OrAssert($_)   } for (@nums) },   
});
[download]

Benchmark: timing 10000 iterations of CarpAssert, OrAssert...
CarpAssert: 11 wallclock secs ( 9.92 usr +  0.04 sys =  9.96 CPU) @ 10
+04.02/s (n=10000)
  OrAssert:  8 wallclock secs ( 7.14 usr +  0.03 sys =  7.17 CPU) @ 13
+94.70/s (n=10000)
             Rate CarpAssert   OrAssert
CarpAssert 1004/s         --       -28%
OrAssert   1395/s        39%         --
[download]

Carp::Assert

Benchmark: timing 10000 iterations of CarpAssert, OrAssert...
CarpAssert:  9 wallclock secs ( 6.50 usr +  0.03 sys =  6.53 CPU) @ 15
+31.39/s (n=10000)
  OrAssert: 10 wallclock secs ( 6.72 usr +  0.02 sys =  6.74 CPU) @ 14
+83.68/s (n=10000)
             Rate   OrAssert CarpAssert
OrAssert   1484/s         --        -3%
CarpAssert 1531/s         3%         --
[download]

sub noOpError {}
sub OrAssert {
    my ($test) = @_;
    ($test < 50) || noOpError("Test is wrong");
    return $test;
}
[download]

Benchmark: timing 10000 iterations of CarpAssert, OrAssert...
CarpAssert:  6 wallclock secs ( 6.54 usr +  0.00 sys =  6.54 CPU) @ 15
+29.05/s (n=10000)
  OrAssert:  7 wallclock secs ( 7.11 usr +  0.02 sys =  7.13 CPU) @ 14
+02.52/s (n=10000)
             Rate   OrAssert CarpAssert
OrAssert   1403/s         --        -8%
CarpAssert 1529/s         9%         --
[download]

An idea you might like to steal from it is to append if DEBUG to your assertions, where DEBUG is a constant that you can set to 1 in development/testing and to 0 in production. That way, you have all of the benefits of assertions in development, and none of the overhead in production (along with none of the benefits.)

Personally I do not like to turn off my assertions, I also see my debug statements as different from assertions. Besides IMO, having the if DEBUG at the end of the statement would really ruin the readability of it all.

-stvn

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