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.