NAME

assertions - select assertions in blocks of code

SYNOPSIS

  sub assert (&) : assertion { &{$_[0]}() }

  use assertions 'foo';
  assert { print "asserting 'foo'\n" };

  {
      use assertions qw( foo bar );
      assert { print "asserting 'foo' and 'bar'\n" };
  }

  {
      use assertions qw( bar );
      assert { print "asserting only 'bar'\n" };
  }

  {
      use assertions ' _ && bar ';
      assert { print "asserting 'foo' && 'bar'\n" };
  }

  assert { print "asserting 'foo' again\n" };

DESCRIPTION

The assertions pragma specifies the tags used to enable and disable the execution of assertion subroutines.

An assertion subroutine is declared with the :assertion attribute. This subroutine is not normally executed : it's optimized away by perl at compile-time.

The assertion pragma associates to its lexical scope one or several assertion tags. Then, to activate the execution of the assertions subroutines in this scope, these tags must be given to perl via the -A command-line option.

SEE ALSO

perlrun.

AUTHOR

Salvador Fandiño, <sfandino@yahoo.com>

COPYRIGHT AND LICENSE

Copyright 2002 by Salvador Fandiño

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