When should you prefer fat comma =>, and when should you avoid it?

In Perl, the fat comma (=>) is often used when you want to associate keys with values in a hash, making the code more readable. However, there are situations where it might be better to avoid using it, particularly when values are not clear or could be confused with code. Here's a brief guide:

When to use fat comma (=>)

• When defining hashes, to improve readability:
my %hash = ( key1 => 'value1', key2 => 'value2', );
• When passing arguments to functions to avoid confusion with commas:
sub example_function { my ($arg1 => $var1, $arg2 => $var2) = @_; }

When to avoid fat comma (=>)

• When the value could be interpreted as a number (e.g., in comparisons):
my @array = (1, 2, 3); my %hash = (1 => $array[0], 2 => $array[1]); # Better to use regular comma