You've run into probably the most vague area of Perl parsing DWIMery. It is the only place in the Perl source code that mentions "weigh". How to interpret such things in a regex is determined by weighing several different criteria so there is no easy explanation as to what Perl will choose. For example, I'm disappointed that in a regex Perl chooses to interpret [$] as the start of a character class followed by the contents of the $] variable. I think it got that DWIM aspect just wrong.

But in your case, I think Perl got the DWIM correct. The string case is fairly straight-forward and mostly just greedy parsing so it always pulls in the trailing {...} to make a hash deref unless you do something to tell it not to.

For the regex case, {5} looks more like a quantifier than like a hash key because a hard-coded number as a hash keys is a bit unlikely, though this isn't a slam-dunk winner.

- tye        

In reply to Re: Interpolation differences between Strings and Regular Expressions (weight) by tye
in thread Interpolation differences between Strings and Regular Expressions by wind

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.