From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2007-08-31T17:35:11+09:00
Subject: Re: Dispatching when function name is stated as a symbol

On 8/31/07, Ronald Fischer <ronald.fischer@venyon.com> wrote:
> Can someone point out an elegant way to solve the following problem?
>
> I have a module with a function f and additional functions g1, g2, ...,
> which basically looks like this:
>
> module M
>   def f(&cb)
>     ...
>     x=cb.call
>     # DO SOMETHING .... see below
>   end
>   def g1(a,b,c)
>     ...
>   end
>   def g2(d,e)
>     ...
>   end
>   # etc
> end
>
> The DO SOMETHING part looks like this: The proc object being called
> is supposed to return an array, where the first element is a symbol
> corresponding to one of the function names g1, g2 ...., and the
> remaining array elements corresponding to the parameters of this
> function. Hence, if
>   x=cb.call
> causes x to contain [:g2, 25, 'dummy'], I would like to execute
>   g2(25,'dummy')
>
> I have not found a convincing way of doing this.

Would this work for you?

def f(&cb)
	x=cb.call
	name = x[0]
	args = x[1..-1]
	send(name, *args);
end
	
def g1(a,b,c)
	puts "g1: #{a}, #{b}, #{c}"
end
	
def g2(d,e)
	puts "g1: #{a}, #{b}, #{c}"
end

irb(main):017:0> f {[:g1, 1, 2, 3]}
g1: 1, 2, 3
=> nil
irb(main):018:0> f {[:g2, 1, 2, 3]}
g2: 1, 2, 3
=> nil

Hope this helps,

Jesus.