pluralization

[Vynce]

not always what you want, but a cute way to approach a standard data presentation issue -- and who can resist use of the x operator?

my $noun = 'iteration';

for my $count (0..2) { 
  my $declension = 's' x (abs($count) != 1);
  print "$count $noun$declension so far...\n";
}

[liverpole]

Interesting, for sure.  I've always favored the pithier version of:

for my $count (0..2) {
  my $s = (1 == $count)? "": "s";
  print "$count iteration$s so far...\n";
}

Of course, it's gotta be tweaked under certain circumstances:

for my $cheese_eaters (0..2) {
  my $noun = (1 == $count)? "mouse": "mice";
  print "$cheese_eaters $noun so far...\n";
}

By the way, the (<constant> == $count) is a habit I picked up from a company which had some good ideas about coding guidelines.  (It was for C, but applies to Perl as well).  The idea is that you can never accidentally write '=' instead of '==' because the compiler will detect an attempt to assign to a constant and forbid it outright.

[Vynce]

i think the x notation should theoretically be faster, because there is no branch -- just a repeat some (possibly zero) number of times.

LHS constants for comparison to avoid assignment is a pretty cool habit. perhaps perlmonks should have a "habits & practices" section.

[liverpole]

I'm not sure I completely agree.  The 'x' operator still has to perform a conditional evaluation at a lower level, and 'abs' will certainly chew up some time.  Here's what I get when I benchmark it:

Program 'benchmark.pl':

#!/usr/bin/perl -w

# Strict
use strict;
use warnings;

# User-defined
my $niter = 2000000;

# Libraries
use Benchmark;

# Main program
timethis($niter, \&sub1);
timethis($niter, \&sub2);

# Subroutines
sub sub1() {
    my $noun = 'iteration';
    for my $count (0..2) {
        my $declension = 's' x (abs($count) != 1);
        my $result = sprintf "$count $noun$declension so far...\n";
    }
}

sub sub2() {
    for my $count (0..2) {
    my $s = (1 == $count)? "": "s";
        my $result = sprintf "$count iteration$s so far...\n";
    }
}

Results:

[liverpole@diamond<28>]% benchmark.pl
timethis 2000000: 25 wallclock secs (20.27 usr +  0.05 sys = 20.32 CPU
+) @ 98425.20/s (n=2000000)
timethis 2000000: 19 wallclock secs (17.12 usr +  0.01 sys = 17.13 CPU
+) @ 116754.23/s (n=2000000)

Of course, I had to change "print" statements to "sprintf", since the program will be ridiculously I/O-bound otherwise.  But since I had to resort to an absurd iteration count anyway, it probably doesn't matter which you use for most cases.

Hey, I love your idea about a Perlmonks "habits & practices" section!  If something like that existed, I would reference it all the time.