From: 1337p337 <1337p337@...>
Date: 2005-09-23T11:54:22+09:00
Subject: Re: static local variables

While there isn't a direct equivalent, you can do something similar.

def fibonacci_generator
	current = 1
	previous = 0
	lambda {
		tmp = previous
		previous = current
		current = tmp + previous
	}
end

You can use it like this:

irb(main):015:0> fib = fibonacci_generator
=> #<Proc:0x00002aaaab22c9c0@(irb):4>
irb(main):016:0> 10.times { puts fib.call }
1
2
3
5
8
13
21
34
55
89

Basically, by returning a proc that contains local state and then calling it,
you can get something similar to a static variable.  Unlike C, though, you can
have multiple instances of the proc.

On 22/09/05, jdm <xyz@xyz.com> wrote:
> i'm trying to create what C calls a static local variable inside a particular
> method, i.e. this variable should not be visible outside the method and its
> value should survive the activation of the method.
>
> instance variables are "static" but visible to all methods of the instance.
>
> local variables are visible only to a particular method but aren't "static".
>
> i've been through the pickaxe book and nothing obvious popped out at me. it
> seems i could synthesize the desired functionality using singleton methods
> attached to a particular instance (or maybe by defining a block within the
> method) but i'm hoping there's a simpler, cleaner way.
>
> thanx in advance.
>
>
>
>