Using Ovid's example above ... 
sub whatFoo {
    if ($_[0] > 7) { 
        return 'ONE'
    } else {
        return 'TWO'
    }
}

sub whatBarBaz {
    my ($bar, $baz) = @_;

    return 'BAR' if $bar;
    return 'BAZ' if $baz;
    return 'DEFAULT';
}

sub no_op { }

my %Dispatch = (
    ONE => {
        BAR => \&firstBar,
        BAZ => \&firstBaz,
    },
    TWO => {
        BAR => \&secondBar,
        BAZ => \&secondBaz,
    },
);

# Put the defaults in as NO-OPs, unless we already have a
# default action
foreach my $key (keys %Dispatch) {
    $Dispatch{$key}{DEFAULT} = \&no_op
        unless exists $Dispatch{$key}{DEFAULT};
}

my $func = $Dispatch{whatFoo($foo)}{whatBarBaz($bar, $baz)};
$func->(@someArgs);

[download]
Seems pretty clear-cut to me ... Plus, it's extensible. If you have a $quz you want to put in, add your QUZ entries to the dispatch and then change whatBarBaz() to allow for QUZ.

------
We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

In reply to How to build a real multi-level dispatch table by dragonchild
in thread Why I Hate Nested If-Else blocks by jeffa

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.