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const::fast(3pm) [debian man page]

Const::Fast(3pm)					User Contributed Perl Documentation					  Const::Fast(3pm)

NAME

       Const::Fast - Facility for creating read-only scalars, arrays, and hashes

VERSION

       version 0.011

SYNOPSIS

	use Const::Fast;

	const my $foo => 'a scalar value';
	const my @bar => qw/a list value/;
	const my %buz => (a => 'hash', of => 'something');

SUBROUTINES
/METHODS
   const $var, $value
   const @var, @value...
   const %var, %value...
       This the only function of this module and it is exported by default. It takes a scalar, array or hash lvalue as first argument, and a list
       of one or more values depending on the type of the first argument as the value for the variable. It will set the variable to that value and
       subsequently make it readonly. Arrays and hashes will be made deeply readonly.

       Exporting is done using Sub::Exporter for flexibility on import.

RATIONALE

       This module was written because I stumbled on some serious issues of Readonly that aren't easily fixable without breaking backwards
       compatibility in subtle ways. In particular Readonly's use of ties is a source of subtle bugs and bad performance. Instead, this module
       uses the builtin readonly feature of perl, making access to the variables just as fast as any normal variable without the weird side-
       effects of ties. Readonly can do the same for scalars when Readonly::XS is installed, but chooses not to do so in the most common case.
       This may change in the future if someone takes up maintenance of Readonly, and the two modules may be convergence if that happens.

CAVEATS

       Perl doesn't distinguish between restricted hashes and readonly hashes. This means that:

	use Const::Fast;
	const my %a => (foo => 1, bar => 2);
	say 1 unless $a{baz}

       Will give the error "Attempt to access disallowed key 'baz' in a restricted hash". You have to use "exists $a{baz}" instead. This is a
       limitation of perl that can hopefully be solved in the future.

ACKNOWLEDGEMENTS

       The interface for this module was inspired by Eric Roode's Readonly. The implementation is inspired by doing everything the opposite way
       Readonly does it.

AUTHOR

       Leon Timmermans <fawaka@gmail.com>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2010 by Leon Timmermans.

       This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

perl v5.14.2							    2012-04-22							  Const::Fast(3pm)

Check Out this Related Man Page

PPIx::Utilities::Statement(3pm) 			User Contributed Perl Documentation			   PPIx::Utilities::Statement(3pm)

NAME

       PPIx::Utilities::Statement - Extensions to PPI::Statement.

VERSION

       This document describes PPIx::Utilities::Statement version 1.1.0.

SYNOPSIS

	   use PPI::Document qw< >;

	   use PPIx::Utilities::Statement qw<
	       get_constant_name_elements_from_declaring_statement
	   >;

	   my $document = PPI::Document->new('Readonly::Scalar my $THINGY => 47.2;');

	   # Returns the PPI::Token::Symbol for "$THINGY".
	   my ($constant) = get_constant_name_elements_from_declaring_statement(
	       $document->schild(0)
	   );

DESCRIPTION

       This is a collection of functions for dealing with PPI::Statements.

INTERFACE

       Nothing is exported by default.

   "get_constant_name_elements_from_declaring_statement($statement)"
       Given a PPI::Statement, if the statement is a Readonly or Const::Fast declaration statement or a "use constant", returns the names of the
       things being defined.

       Given

	   use constant 1.16 FOO => 'bar';

       this will return the PPI::Token::Word containing 'FOO'.	Given

	   use constant 1.16 { FOO => 'bar', 'BAZ' => 'burfle' };

       this will return a list of the PPI::Tokens containing 'FOO' and 'BAZ'. Similarly, given

	   Readonly::Hash my %FOO => ( bar => 'baz' );

       or

	   const my %FOO => ( bar => 'baz' );

       this will return the PPI::Token::Symbol containing '%FOO'.

BUGS AND LIMITATIONS

       Please report any bugs or feature requests to "bug-ppix-utilities@rt.cpan.org", or through the web interface at <http://rt.cpan.org>.

AUTHOR

       Thomas R. Wyant, III "<wyant at cpan dot org>"

COPYRIGHT

       Copyright (c) 2009-2010 Thomas R. Wyant, III.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.  The full text of this license
       can be found in the LICENSE file included with this module.

perl v5.10.1							    2010-12-03					   PPIx::Utilities::Statement(3pm)
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