I actually gave five examples of side effects (looking at a value, assignment, warn, processing @ARGV, reading from a handle).

Well, you got me there. Shouldn't answer nodes right after rolling out of bed. Now, you might not call them side-effects, but than you have a private definition of a side-effect. Using private definitions doesn't contribute to succesful communication.

I thought that was quite clear.
Personally, I don't consider your two examples as side effects (even though some would)

Yes from a language design standpoint, Perl is full of side effects. I'm talking about the expectations of people using Perl. Yes, it's a well know trap and easy to avoid.

But it's non-intuitive and dare I say non-sensical. I'd be hard pressed to think of any situation were someone would want their loop iterations influenced transparently by code outside the current scope. Certainly that's what most people don't want the majority of the time. It doesn't follow expectation.


-Lee

perl digital dash (in progress)

In reply to Re^11: Spot the bug by shotgunefx
in thread Spot the bug by tlm

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.