From: Robert Klemme <shortcutter@...>
Date: 2009-01-10T03:09:39+09:00
Subject: Re: Using a method as input to another method

On 09.01.2009 18:48, Erick Star wrote:
> Hi, I was wondering if it was possible to do something like the
> following:
> 
> class A
> 
> def b
>  stuff
> end
> 
> def c
>  stuff
> end
> 
> def d(x)
>  self.x
> end
> end

You can leave out method d and use send() directly, i.e.

a = A.new
a.send(:b)

However:

> Then use thing.d(a) with thing an instance of A?
> Basically, given a long list of methods belonging to a class, if you
> wanted ruby to apply methods based on the state of the program, how
> would you set it up besides doing:
> 
> case A
> when b
>  thing.stuff
> when c
>  thing.otherstuff

State pattern comes to mind.

http://en.wikipedia.org/wiki/State_pattern

There are a number of options for modeling this besides of state 
pattern.  Generally any OO approach exploits overriding of methods, i.e. 
you have several classes which share a method with identical signature 
but different behavior.

Kind regards

	robert


-- 
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