From: Daniel Berger <djberg96@...>
Date: 2006-11-30T00:45:11+09:00
Subject: Re: `attr_accessor` and predicate/question mark methods.

Tim Becker wrote:
> Hi,
> I just stumbled across this weird behaviour and I'm puzzled that I've
> not noticed it before. If I use `attr_accessor` to define a predicate
> method, i.e. one ending in a question mark, the following happens:
>
> class Test
> attr_accessor :weird?
> end
>
> t = new Test
> t.weird?     => nil
> t.weird?=true     => SyntaxError: compile error
>
> Which is only mildly confusing, considering it's implied somewhere in
> the pickaxe book that bangs or question marks are only allowed at the
> end of method names. In fact:
>
> class Test2
> def weird?= val
> end
> end
>
> fails with `SyntaxError` as well. What's baffling me is that
> `attr_accessor`'s  is capable of adding the method `weird?=`, which
> can be verified calling `methods`:
>
> t.methods => [... "weird?=" ...]
>
> The method is there, only calling it causes the `SyntaxError`... Am I
> missing something entirely obvious here?
>    -tim

This was a bug that was "fixed" in a 1.8.5.  In 1.8.5 trying to do
'attr_accessor :weird?' raises a NameError.

I had voted that doing 'attr_accessor :weird?' should create a "weird?"
and "weird=" method, but I was shot down by programmers who were more
interested in being correct than useful (am I bitter? nah).  See
ruby-core:5796 and following for more information.

Regards,

Dan

PS - My apologies if this is a double post - Google server flaked out.