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ConstOptree(3pm) User Contributed Perl Documentation ConstOptree(3pm)

NAME

B::ConstOptree - Optree constant folding for $^O, $^V, and $]

SYNOPSIS

 $ perl -MO=ConstOptree -MO=Deparse} -e \
        'require ($^O eq "MSWin32" ? "Win32.pm" : "POSIX.pm")'
 require 'POSIX.pm';
 -e syntax OK

DESCRIPTION

This module propagates constant folding for $^O, $^V, and $] variables by installing custom PL_check handlers for numeric and string comparison opcodes. In the handlers, references to $^O, $^V, and $] arguments are replaced with constant terms like "linux", v5.16.1, and 5.016001, respectively.

CAVEATS

Since regexp matching is not subject to constant folding, expressions like "$^O =~ /win32/i" will not be reduced.

AUTHOR

Written by Alexey Tourbin <at@altlinux.org>.

COPYING

Copyright (c) 2012 Alexey Tourbin

This is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

2024-03-07 perl v5.38.2