From: Joel VanderWerf <vjoel@...>
Date: 2009-04-10T02:54:16+09:00
Subject: Re: Calling a Function Before It's Defined

Mark Bilk wrote:
> I would like to be able to call a function (or a class,
> when I get more object-oriented) earlier in the program
> file than where I define it.  Such a "top-down" layout
> seems natural to me.  In C I could use a function
> prototype for this.  If I try it in Ruby, I get an error
> (see code below).

Two ways:

foo
BEGIN {
   def foo; end
}

or

END {
   foo
}
def foo; end

> Even if I do define everything before I use it, how could
> I write a recursive function, or two mutually recursive
> functions?

Define the two functions before you call either one. No prob.

def foo(n); p n; bar(n-1); end
def bar(n); foo(n) if n>0; end

p bar(3)

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407