From: David Masover <ninja@...>
Date: 2008-06-04T04:57:29+09:00
Subject: Re: Beginner help

On Tuesday 03 June 2008 13:38:38 Justin To wrote:
> def meth(proc)
>  yield("hello")
> end
> 
> meth(proc) {|var1|  puts "block" }

I'm not sure that's right. Basic way to do this would be:

def meth
  yield("hello")
end

meth { |var1| puts "block" }

Looking at your original message, are you wanting to do this with two 
blocks/procs? For example:

def meth(some_proc)
  some_proc.call 'calling proc'
  yield 'calling block'
end

meth(lambda{|x| puts x; puts 'in proc'}) {|x puts x; puts 'in block'}

That is really, really cumbersome to use. I haven't found a good way around 
it, though...

> Ok... I think I'm just confused about the above example... when i run 
> this an error comes up:
>  blank.rb:5:in `proc': tried to create Proc object without a block 
> (ArgumentError)
>   from blank.rb:5

The 'proc' method, by itself, is trying to create a Proc object. So, for 
example:

foo = proc { |var1| puts "block" }

Now "foo" is the proc, and can be passed around.