I don't think 'excessive overhead' has any meaning without a context. It might be excessive for some applications and not for others.

And I think the interface is sufficiently interesting that the overhead might be worth spending. Being able to write 

    $stack = newitem;

[download]
for a push operation and 
    $top = $stack;

[download]
for a pop operation is pretty clever.

But one thing I would do differently is to resolve the fifo/lifo string to boolean in the TIESCALAR method instead of doing it over and over on every FETCH. Just change the TIESCALAR like this: 

sub TIESCALAR {
    return unless $_[1] =~ /[fl]i[fl]o/i;
    my $stack = $_[1] =~ /([fl])i\1o/i;
)   return bless [$stack,[]], $_[0];
}

[download]
Then we can eliminate the regex from FETCH; the if line becomes simply: 
    if ($_[0]->[0]) {

[download]

In reply to Re: Simple stack implementation by Dominus
in thread Simple stack implementation by quidity

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.