From: David Masover <ninja@...>
Date: 2008-05-29T07:01:45+09:00
Subject: Re: The duck's backside

On Wednesday 28 May 2008 16:25:15 John Carter wrote:

> class MyObject
> 
>    def initialize( _a, _b, _c)
>      @a = _a.quacks_like( :qwaak, :waddle, :swim)
>      @b = _b.static_type_check String
>      @c = _c.polymorphic_type_check MyBaseClass
>    end
> 
>    # Without the checks above, the exceptions would be thrown here, with the 
buggyline nowhere on the backtrace!
>    def my_use
>       @a.qwaak( @b) + @c
>    end
> end

I'm fine with that, because 99% of the time, I'll never hit that exception. 
When I do, it's usually possible to deal with it -- in this case, you would 
find where @a is set, and add a check there.

I think you're arguing to add that check first. I would call that premature 
strictness -- but if you have to do it, I like your way.

Oh, also: Most of the time, I use setters/getters (attr_accessor), even when 
something's mostly going to be internal. That simplifies this process -- I 
know there was a problem with a, so I can override a's setter with something 
that performs the same check. But that's also probably overkill -- if a class 
can't fit on a page, it's probably too big and should be broken down.