Every now and again, I want to set the value of a number of properties on an object from a hash, where the method name is the same as the key name, but with a prefix, eg
$object->set_date( $hash{ date } );
But how to do this for all the keys in a hash? I've thought of two methods:
Method 1:
---------
for ( keys %hash ) {
my $method = "set_$_";
$object->$method( $hash{ $_ } );
}
Method 2:
---------
for ( keys %hash ) {
$object->${ \"set_$_" }( $hash{ $_ } );
}
I prefer the second method, because it is shorter, but (1) it is less readable and (2) Perl::Tidy reformats it with a space before the arrow, which still works, but looks rather odd:
$object ->${ \"set_$_" }( $hash{$_} );
Which method would you prefer? One of the above, or some other syntax?
(Note: I benchmarked the difference between these two, and while the temp var is slightly faster, the difference is negligible.)
#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw(cmpthese);
package foo;
{
sub set_var1 { }
sub set_var2 { }
sub set_var3 { }
sub set_var4 { }
sub set_var5 { }
}
package main;
my $object = bless {}, 'foo';
my %hash = map { ( "var$_" => $_ ) } ( 1 .. 5 );
sub temp_var {
for ( keys %hash ) {
my $method = "set_$_";
$object->$method( $hash{$_} );
}
}
sub deref {
for ( keys %hash ) {
$object ->${ \"set_$_" }( $hash{$_} );
}
}
cmpthese( 1_000_000,
{ temp_var => \&temp_var,
deref => \&deref
}
);
Results:
Rate deref temp_var
deref 176991/s -- -18%
temp_var 215054/s 22% --
Update: corrected a typo in Method 2, thanks to zwon for pointing it out
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