Re^3: Style: buried variables or double referencing?

Depends. Readonly is slow, and not everyone can use Readonly::XS. The following code takes 48 seconds:

use Readonly;
Readonly $C1 => 1;

my $t0 = time();
my $a = 2;
for (1 .. 10000000) {
    if ($a ++ == $C1) {
        ;
    }
}
print time() - $t0;
[download]

When this takes 4 second:

use constant C1 => 1;

my $t0 = time();
my $a = 2;
for (1 .. 10000000) {
    if ($a ++ == C1) {
        ;
    }
}
print time() - $t0;
[download]

If performance is important, use constant.

Comment on Re^3: Style: buried variables or double referencing? Select or Download Code

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Re^4: Style: buried variables or double referencing? by tilly (Archbishop) on Aug 21, 2005 at 05:06 UTC
I'd be happier developing with a function that called Readonly in development and then something like this in production: `sub fake_readonly { $_[0] = $_[1]; }` [download] And now you get most of the advantages of Readonly, but performance is not a problem. (I don't like constant because I'm a big fan of interpolating, and I often have to check whether someone has a constant or function because I'm afraid that it will try to suck up arguments.)	[reply] [d/l]
Re^4: Style: buried variables or double referencing? by Anonymous Monk on Aug 22, 2005 at 09:58 UTC
That's a difference of 4.4 microseconds. That's a difference I'm willing to take in most of my programs.	[reply]