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NAME
Loop - Smart, Simple, Recursive Iterators for Perl programming.
SYNOPSIS
use Loop;
Loop::Array @array, sub
{
my ($index,$value)=@_;
print "at index '$index', value='$value'\n";
}
ABSTRACT
This module is intended to implement simple iterators on perl variables with little code required of the programmer using them.
Some additional advantages over standard perl iterators:
Array iterators give access to the current index within the array. Hash iterators can be nested upon the same hash without conflicts. File iterators allow simple file munging in a few lines of code.
DESCRIPTION
Loop on an Array
# loop on an array, at index 3, change the value in the array to "three"
my @array = qw (alpha bravo charlie delta echo);
Loop::Array @array, sub
{
my($index,$val)=@_;
if($index == 3)
{
# modify the element in the original array
# note that when you want to change the original array,
# you must assign to the parameter array @_
$_[1] = 'three';
}
}
Loop on a Hash
# loop on a hash, perform nested iteration on the same hash.
my %hash =
(
blue => 'moon',
green => 'egg',
red => 'baron',
);
Loop::Hash (%hash, sub
{
my($key1,$val1)=@_;
print "checking key1 $key1, val1 $val1 for collisions \n";
Loop::Hash (%hash, sub
{
my($key2,$val2)=@_;
print "\tchecking key2 $key2, val2 $val2 for collisions \n";
print "\t $val2 is not $key1\n"
unless($key1 eq $key2);
return;
});
});
Loop on a File
# loop through a file, read it line by line, and grep for a string.
Loop::File "tfile.pl", sub
{
my($linenum,$linestr)=@_;
if($linestr =~ /search/)
{
print "found at line $linenum: $linestr";
}
};
EXPORT
none
SEE ALSO
AUTHOR
Greg London, http://www.greglondon.com
COPYRIGHT AND LICENSE
Copyright 2003 by Greg London, All Rights Reserved
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.