/ 
Loop-Control-0.01
River stage zero No dependents
/ Loop::Control

NAME

Loop::Control - FIRST and NEXT functions for loops

SYNOPSIS

use Loop::Control;

for (1..10) {
    FIRST { print "called only in the first iteration" };
    FIRST { print "also called only in the first iteration" };
    # do things
    NEXT { print "called at the end of each iteration" };
    NEXT { print "also called at the end of each iteration" };
    # do more things
    next if rand() < 0.5
    # the NEXT code will be executed even if the loop is ended with next()
}

DESCRIPTION

This module provides ways to execute code at certain points in a for or while loop that are outside the normal control flow. For example, you could have code that executes only during the first iteration of a loop, or code that executes after every iteration of the loop, regardless of how the iteration ended (normally or via next). .

METHODS

FIRST

Automatically exported, this function is meant to be placed inside a for or while loop. It takes a code block which it will execute only during the first iteration of the loop. They block is run at the point where the FIRST statement occurs. You can specify several FIRST blocks in a loop. If the loop is called recursively, each recursion level is treated as a separate loop.

The block will have additional entries in the call stack, that is, caller() will not show the same results as the code that is placed directly in the loop.

NEXT

Automatically exported, this function is meant to be placed inside a for or while loop. It takes a code block which it will execute after each iteration of the loop, regardless of whether the loop iteration ended normally or via next. You can specify several NEXT blocks in a loop, and they will be run in the reverse order in which they were encountered.

The block will have additional entries in the call stack, that is, caller() will not show the same results as the code that is placed directly in the loop.

callstack_depth

Convenience function that returns the number of levels on the call stack, that is, the maximum number for which caller($i) will return data. The number includes the call stack entry for callstack_depth() itself. This function is used by NEXT and is not exported.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests through the web interface at http://rt.cpan.org.

INSTALLATION

See perlmodinstall for information and options on installing Perl modules.

AVAILABILITY

The latest version of this module is available from the Comprehensive Perl Archive Network (CPAN). Visit http://www.perl.com/CPAN/ to find a CPAN site near you. Or see http://www.perl.com/CPAN/authors/id/M/MA/MARCEL/.

The development version lives at http://github.com/hanekomu/loop-control/. Instead of sending patches, please fork this project using the standard git and github infrastructure.

AUTHORS

Marcel Grünauer, <marcel@cpan.org>

COPYRIGHT AND LICENSE

Copyright 2009 by Marcel Grünauer

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.