NAME

Context::Handle - A convenient context propagation proxy thingy.

SYNOPSIS

use Context::Handle qw/context_sensitive/;

            sub wrapping {
                    my $rv = context_sensitive {
                            $some_thing->method(); # anything really
                    };

                    # you can do anything here

                    $rv->return; # returns the value in the right context

                    # not reached
            }

DESCRIPTION

This module lets you delegate to another method and return the value without caring about context propagation.

The level of support is tied to what Want does - this module tries to make all the distinctions Want can make fully supported, for example array dereference context, boolean context, etc.

EXPORTS

Nothing is exported by default.

context_sensitive BLOCK

This is a convenience shortcut that calls "new"

METHODS
Regular Usage
new $code

        This method invokes $code in the calling sub's context, and returns
        an object that saves the return value.

rv_container

        This instance method returns the return value container object. The
        only useful methods for the RV containers is "value", which has a
        delegator anyway.

value

This returns the value from the "rv_container"

return

This (ab)uses Want to perform a double return.

Saying

$rv->return;

is just like

return $rv->value;

Introspection
Incidientially due to the needs of the wrapping layer this module also provides an OO interface to Want, more or less ;-)

bool
void
scalar
list
refarray
refhash
refscalar
refobject
refcode
refglob

All of these methods return boolean values, with respect to the

TODO

• pseudoboolean context - the right side of && and the left side of || evaulate in boolean context, but still return a meaningful value.
• Glob assignment context. I'm not sure how to make the value propagate back once it's been assigned to the glob - it's hard to know what it is without inspecting the slots and that's kinda tricky.
• Lvalue assignment
• use Sub::Uplevel to hide the wrapping
• context arity - Want's count stuff. This can probably be done using @list[0..$x] = (...), but might need to be emulated with eval. See "perldoc -f split".

ACKNOWLEGMENTS

Robin Houston for Want and lots of help by email

AUTHOR

Yuval Kogman <nothingmuch@woobling.org>

COPYRIGHT & LICENSE

            Copyright (c) 2006 the aforementioned authors. All rights
            reserved. This program is free software; you can redistribute
            it and/or modify it under the same terms as Perl itself.