Unconventional Looping with goto

By: w1ldc4rd-w1z4rd
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Today, we’re exploring a Perl script that demonstrates some unconventional techniques: using goto to create a loop in an unexpected place. Let’s break down this fascinating piece of code:

#!/usr/bin/env perl

use feature qw|say|;

my $n = 7;

if ($n == 10)
{
    say qq|I see a ${n}!|;
}
else
{ R:
    say qq(Hmmm... looking for 10... \$n = ${\$n++});
    sleep 1; 
    $n > 10 ? say qq(Yay! It's a ${\--$n}!) : goto R;
}

Let’s dissect this script and explore its unique features:

The line:

say qq(Hmmm... looking for 10... \$n = ${\$n++});

Does two things:

Note the use of ${} for complex expressions in interpolation. ${\$n++} dereferences $n, increments it, and interpolates the result.

$n > 10 ? say qq(Yay! It's a ${\--$n}!) : goto R;

If $n is greater than 10, it decrements $n and prints a success message. Otherwise, it jumps back to the R: label, creating a loop.

This script demonstrates how goto can be used to create a loop in an unconventional place - inside an else block. While goto is often frowned upon due to its potential to create spaghetti code, this example shows how it can be used creatively.

This code is a fascinating demonstration of Perl’s capabilities, it’s not typically recommended for production code. Clear, maintainable code is usually preferable to clever tricks. However, understanding these techniques can deepen your appreciation of Perl’s flexibility and power.

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