From: Robert Dober <robert.dober@...>
Date: 2010-04-18T02:58:07+09:00
Subject: Re: Undifined local variable or method error

On Sat, Apr 17, 2010 at 7:30 PM, Simbolla Simbolla <vinod236@gmail.com> wrote:
> Hi all,
>
> Below is my code
>
>  h={}
>  arr=[]
> def gethash
>  h[1]=0
>  return h
> end
> arr[0]=gethash
> puts arr[0].each {|k,v| puts "key #{k} value #{v}"}

to my dismay
def xxx... end
is *not* a closure
while
define_method :xxx is
IOW
h is just not visible in def while it would if you define gethas via
define_method

be careful though on the toplevel you cannot use define_method, do
something like
include( Module::new do
  h = {}
  define_method :xxx do h.tap{ |hh| h[1] = 0 } end
end )

puts xxx
xxx[:a] = 42
puts xxx

oh yes this code is ugly, but I wanted to demonstrate the semantics...
HTH
R.


-- 
The best way to predict the future is to invent it.
-- Alan Kay