Perl isn't a good language for writing fast code in.

If I agreed with this I'd be disappointed - the perl porters put a lot of effort into improving the speed of perl, and trying to avoid speed loss.

It is true that perl wouldn't be a good choice for an interrupt handler (say), where you need to be able to impose very tight bounds on average and maximum latency.

However I have written lots of code that needed to be fast simply because it was doing an awful lot of work - the sort of recursive calculations that require billions of iterations - and I've found perl fine for such work. And for those cases, shaving a few microseconds can make a noticeable difference.

Similarly, when some code will create many millions of in-memory records, the few bytes-per-record saving that means you don't start swapping can also make a big difference.

I think the assembler background does give a helpful tint to the mindset, in that you get into the habit of applying the various micro-optimisations automatically, and the benefits do mount up.

The important thing though is to keep a balance, and not let the optimisations affect readability (hence maintainability) too much; and to remember that finding a slightly better algorithm will likely put all the micro-optimisations into the pale.

Hugo

In reply to Re^3: Using aliases in for loops or not? by hv
in thread Using aliases in for loops or not? by jkva

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.