NAME

Method::Utils - functional-style utilities for method calls

FUNCTIONS

All of the following functions are intended to be used as method call modifiers. That is, they return a SCALAR reference to a CODE reference which allows them to be used in the following syntax

 $ball->${possibly "bounce"}( "10 metres" );

Since the returned double-reference can be dereferenced by ${ } to obtain the CODE reference directly, it can be used to create new methods. For example:

 *bounce_if_you_can = ${possibly "bounce"};

The following utilities are described from the perspective of directly invoking the returned code, as in the first example.

possibly $method

Invokes the named method on the object or class and return what it returned, if it exists. If the method does not exist, returns undef in scalar context or the empty list in list context.

inwardly $method

outwardly $method

Invokes the named method on the object or class for every class that provides such a method in the @ISA heirarchy, not just the first one that is found. inwardly starts its search at the topmost class; that is, the class name (or type of the object) provided, and starts searching down towards superclasses. outwardly starts its search at the base-most superclass, searching upward before finally ending at the topmost class.

In the case of multiple inheritance, subclasses are always searched in the order that they appear in the @ISA array.

In the case that multiple inheritance brings the same subclass in more than once, they are arranged into a consistent order. That is, inwardly ensures that no superclass will be searched until every subclass that uses it has been searched first; while outwardly ensures that no superclass will be searched before every subclass that it uses has been searched already.

AUTHOR

Paul Evans <leonerd@leonerd.org.uk>