NAME
Variable::Temp - Temporarily change the value of a variable.
VERSION
Version 0.03
SYNOPSIS
use Variable::Temp 'temp';
my $x = 1;
say $x; # 1
{
temp $x = 2;
say $x; # 2
}
say $x; # 1
DESCRIPTION
This module provides an utility routine that can be used to temporarily
change the value of a scalar, array or hash variable, until the end of
the current scope is reached where the original value of the variable is
restored. It is similar to "local", except that it can be applied onto
lexicals as well as globals, and that it replaces values by copying the
new value into the container variable instead of by aliasing.
FUNCTIONS
"temp"
temp $var;
temp $var = $value;
temp @var;
temp @var = \@value;
temp %var;
temp %var = \%value;
Temporarily replaces the value of the lexical or global variable $var by
$value (respectively @var by @value, %var by %value), or by "undef" if
$value is omitted (respectively empties @var and %var if the second
argument is omitted), until the end of the current scope. Any subsequent
assignments to this variable in the current (or any inferior) scope will
not affect the original value which will be restored into the variable
at scope end. Several "temp" calls can be made onto the same variable,
and the restore are processed in reverse order.
Note that destructors associated with the variable will not be called
when "temp" sets the temporary value, but only at the natural end of
life of the variable. They will trigger after any destructor associated
with the replacement value.
Due to a shortcoming in the handling of the "\$" prototype, which was
addressed in "perl" 5.14, the pseudo-statement "temp $var = $value" will
cause compilation errors on "perl" 5.12.x and below. If you want your
code to run on these versions of "perl", you are encouraged to use
"set_temp" instead.
"set_temp"
set_temp $var;
set_temp $var => $value;
set_temp @var;
set_temp @var => \@value;
set_temp %var;
set_temp %var => \%value;
A non-lvalue variant of "temp" that can be used with any version of
"perl".
EXPORT
The functions "temp" and "set_temp" are only exported on request by
specifying their names in the module import list.
DEPENDENCIES
perl 5.6.
Exporter (core since perl 5).
Scope::Upper.
Variable::Magic 0.51.
SEE ALSO
Scope::Upper.
"local" in perlfunc.
AUTHOR
Vincent Pit, "<perl at profvince.com>", <
http://www.profvince.com>.
You can contact me by mail or on "irc.perl.org" (vincent).
BUGS
Please report any bugs or feature requests to "bug-variable-temp at
rt.cpan.org", or through the web interface at
<
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Variable-Temp>. I will
be notified, and then you'll automatically be notified of progress on
your bug as I make changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc Variable::Temp
COPYRIGHT & LICENSE
Copyright 2015 Vincent Pit, all rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
