From: Matt Maycock <ummaycoc@...>
Date: 2004-12-24T14:57:54+09:00
Subject: Re: SimpleDelegate (was Re: Inconsistency with IO.readlines)

So I glanced at delegate in the past but never really used it.  Today,
I saw this, and rewrote some old code thinking that using that would
be easier (this was after I decided to post but before clicking submit
[obviously :-)] - so you guys got my cutting edge changes!  really
just cleaned out 6 or so lines...)

My use of SimpleDelegator is that I don't want a case like this:
handle = nil
input_reader("myfile") {|handle| ...}
some_func(handle)

granted, the file ensures that things are closed off so I really don't
have to, but to go along with the idea of how things `should be' - I
used simple delegator for __set_obj__.  Just design philosophy.

The only case I can think of for this mattering in the file I gave is this:

handle = nil
input_reader(some_arg) {|handle| ...}
handle.puts "Meow Mix Please Deliver"

depending on the value of some_arg (nil or '-' vs otherwise) - the
above code works as expected.  This is especially important if you
factored your code such that inside {|handle| ...} all you did was
invoke a method and pass handle to it.  Now, you have a `bug' and it
doesn't event really look like anything remotely inputy-outputy except
for my function name.  So the guarantee of failure under any arguments
(ie purity in a sort of functional sense) is the benefit wrt the
handle.puts line, above.

I may have babbled there a bit - it's late.

Matthew Maycock

-- 
There's no word in the English language for what you do to the thing a
dead thing delegated to chase after you to make it stop chasing you.