Check::ISA(3) User Contributed Perl Documentation Check::ISA(3)NAMECheck::ISA - DWIM, correct checking of an object's class
SYNOPSIS
use Check::ISA;
if ( obj($foo, "SomeClass") ) {
$foo->some_method;
}
# instead of one of these methods:
UNIVERSAL::isa($foo, "SomeClass") # WRONG
ref $obj eq "SomeClass"; # VERY WRONG
$foo->isa("SomeClass") # May die
local $@; eval { $foo->isa("SomeClass") } # too long
DESCRIPTION
This module provides several functions to assist in testing whether a
value is an object, and if so asking about its class.
FUNCTIONS
obj $thing, [ $class ]
This function tests if $thing is an object.
If $class is provided, it also tests tests whether
"$thing->isa($class)".
$thing is considered an object if it's blessed, or if it's a "GLOB"
with a valid "IO" slot (the "IO" slot contains a FileHandle object
which is the actual invocant). This corresponds directly to
"gv_fetchmethod".
obj_does $thing, [ $class_or_role ]
Just like "obj" but uses "DOES" in UNIVERSAL instead of "isa" in
UNIVERSAL.
"DOES" in UNIVERSAL is just like "isa", except it's use is
encouraged to query about an interface, as opposed to the object
structure. If "DOES" is not overridden by th ebject, calling it is
semantically identical to calling "isa".
This is probably reccomended over "obj" for interoperability, but
can be slower on Perls before 5.10.
Note that "DOES" in UNIVERSAL
inv $thing, [ $class_or_role ]
Just like "obj_does", but also returns true for classes.
Note that this method is slower, but is supposed to return true for
any value you can call methods on (class, object, filehandle, etc).
Look into autobox if you would like to be able to call methods on
all values.
obj_can $thing, $method
inv_can $thing, $method
Checks if $thing is an object or class, and calls "can" on $thing
if appropriate.
SEE ALSO
UNIVERSAL, Params::Util, autobox, Moose, asa
VERSION CONTROL
This module is maintained using Darcs. You can get the latest version
from <http://nothingmuch.woobling.org/code>, and use "darcs send" to
commit changes.
AUTHOR
Yuval Kogman <nothingmuch@woobling.org>
COPYRIGHT
Copyright (c) 2008 Yuval Kogman. All rights reserved
This program is free software; you can redistribute
it and/or modify it under the same terms as Perl itself.
perl v5.14.1 2008-07-25 Check::ISA(3)
