note
tobyink
<p>Stringy eval has its uses. [mod://Moose] and [mod://Moo] use it extensively for creating fast inlined accessors and constructors. [mod://Template|Template-Toolkit] uses it to create templates.</p>
<p>However it can also enable all sorts of ugly practices. For example, poor man's symbolic references...</p>
<c>
use strict;
my $red = '#ff0000';
my $green = '#00ff00';
my $blue = '#0000ff';
my $colour = 'green';
my $hex = eval "\$$colour"; # symbolic reference
print "$hex\n";
</c>
<p>When many newcomers turn to stringy eval, it's often because they're unaware of a better solution to their problem.</p>
<p>This is my problem with [mod://Perl::Critic]. It takes a generally good guideline (stringy eval is often a bad idea; investigate other options first) and turns it into a concrete rule.</p>
<p>Yes, of course there's <c>no critic</c> comments but I don't really want to litter those around my code like rat droppings. (<c>no strict</c> and <c>no warnings</c> are already enough of an eyesore.)</p>
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<tt>perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'
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