Omg, I love this. Did you ever have a clear, slick little function that needs to return a boolean, and you also want to communicate an error condition? You basically have the choice of returning two values, reversing the consuming condition (meaning an empty return value be considered true), or using a string reference as an argument to the function.

Witness Perl 6: 
sub slick()
{
    if do-stuff
    {
      return "SomeValue";
    }
    else
    {
      return "Some error message" but False;
    }
}

if my $result = slick
{
    process( $result );
}
else
{
    log-error( $result );
}

[download]


holli

You can lead your users to water, but alas, you cannot drown them.

In reply to [Perl 6]: Small discoveries V, True / False / FileNotFound by holli

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