I'm saying it's a bad assumption to make.

We know that the perl interpreter will parse this equivalently to: 

my @hiddenlist = (
     'A', 1,
     'A', 2,
     'A', 3
);
my %lilhash;
while (@hiddenlist)
{
     my $hiddenkey = shift @hiddenlist;
     $lilhash{$hiddenkey} = shift @hiddenlist;
}
print $lilhash{'A'};

[download]
However, the kinds of assumptions you are making have been made by many folks for years, and it's this kind of assumption that can stymy any interesting optimizations that the interpreter could do with bulk insertions.

I just think it's a bad idea when the word "order" and the word "hash" come anywhere near each other to start making such assumptions. Regardless of how safe or well-entrenched the idiom may be, my advice is: the hash is unordered and the list is ordered and if you care about order, be explicit.

--
[ e d @ h a l l e y . c c ]

In reply to Re^3: Bulk hash population order by halley
in thread Bulk hash population order by JakeIII

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.