From: Clifford Heath <no.spam@...>
Date: 2007-03-19T09:10:05+09:00
Subject: Re: attr_accessor

David A. Black wrote:
> Wouldn't it be better to call that checked_attr?  I'm just thinking
> that it's mostly checking the class, rather than the type

You have the choice of using class checking or block-based checking,
which can perform whatever type checks are relevant, including respond_to?
and related checks. The parameter list consists of a list of any of four
kinds of things:
* a Class (which is used for subsequent class checks),
* nil (indicating that nil values are allowed),
* a Symbol, which creates an attribute having the defined checks,
* any other value, which is used as a default value.
The block, if any, is applied to all created attributes.

Class checking is just a shorthand limited form of type checking. I'm
fully aware if the distinction, but this method encourages type checking,
not just class checking, so I think it's correctly named.

The gem also contains "array_attr", which creates a subclass of Array that
overrides every mutating method of Array to provide the same checking for
array attributes as well (with the exception of nil and default values).

Take a look at the RDoc for more info.

Clifford Heath.