tye, you're just picking the nits in a different way. And, to be honest, I've never thought about "undef" as "uninit". In more general computer science terms, I would expect: 

  my   $t;  # perl
  int* pi;  // C/C++

[download]
to be uninitialised. But I would expect: 
  my   $t = undef; # perl
  int* pi = NULL;  // C/C++

[download]
to be initialised but not really usuable. The fact that perl guarantees that uninitialised variables are undef allows the semantics you're arguing for, that they mean the same thing in perl, but that just seems to be an accident due to a feature.

I don't think I would really be in favour of having the perl runtime distinguish between undef and uninitialised - that's just more code to run in lots of places, and would likely break another feature of perl: autovivication. Just as simply assigning to $h{blah} will create the blah key, shouldn't using $a automatically initialise ... to undef? IMNSHO, fixing the error message is sufficient. And all that would break is the test suite for perl itself ... and a few other modules that catch warnings and respond to them (in other words, I understand why it's not being fixed).

What we probably should be doing is giving our error messages and warnings a prefix tag that our code can look for instead. Rather than "Use of uninitialized value in ...", why not "PERL0183W: Use of uninitialized value in ..."? With the latter, we can change the text all we want, as long as the prefix stays the same. All tests, signal handlers (for __WARN__ and __DIE__), and $@ checks could simply look for /^PERL0183W:/, and text changing won't affect them. I realise that the majority of error and warning messages won't change. But by having it as a standard for all internal messages, we won't need to worry about the ones that do need change.


NOTE: if the original post had "use diagnostics", it would tell you that "an undefined value was used as if it were already defined." Then this whole thread might have been averted, and I would not have had to tell Ovid to calm down ;-}

In reply to Re^4: A bit more clarity on uninitialized value in string ne (init vs def) by Tanktalus
in thread A bit more clarity on uninitialized value in string ne by wolis

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.