in reply to Cheap idioms

On the subject of cheap idioms... 
select( ( select(STDOUT), $| = 1 )[0] );

[download]
Took me a few minutes to work out, but I like it, a lot actually.

:-)

--- demerphq
my friends call me, usually because I'm late....

Replies are listed 'Best First'.
Re: Re: Cheap idioms
by Juerd (Abbot) on Oct 14, 2002 at 14:16 UTC

    select( ( select(STDOUT), $| = 1 )[0] );

    This only works if the inner select is evaluated before the assignment is, and I can't find any specification of evaluation order (remember ++$a, $a++, ++$a?)

    That's why I don't dare to use this idiom, although I see it often. I still prefer STDOUT->autoflush(1) (using IO::Handle). It's shorter too :) 

    - Yes, I reinvent wheels.
- Spam: Visit eurotraQ.

[reply]
[d/l]
[select]
      Ah, but you're wrong. In a simple list, as perlop explicitly states, operands are evaluated left-to-right. Otherwise, you couldn't write print("Done.\n"), exit if $done;

      either, but we all know that it works, right? Your example is problematic because is uses pre- and postincrement operators which mess with the order of side effects.

      IO::Handle loads over 1,000 lines of code - if it's just for a single autoflush, what's the point? Especially seeing as the select idiom is known and even delivered with the perldocs, it's safe to assume it isn't cryptic.

      Makeshifts last the longest.

[reply]
[d/l]
        Im sorry but I fail to understand how both these idioms work. I can see why it slurps a file, but cant really say exactly how... Could somebody explain the magic with ARGV?
[reply]

In Section Meditations