From: "List.rb" <list.rb@...>
Date: 2008-11-13T15:14:35+09:00
Subject: Re: Issue with block and getting to local variables

One thing with locals that got me is that you have to define them  
first so the /parser?/ doesn't bail.

I.e

### breaks:
lamb = lambda { a+b }
a = 1
b = 2
p lamb.call


You must put a,b = nil,nil before the lambda definition :-/

( sorry for top post, on iphone just realized it, no clipboard )

On Nov 12, 2008, at 10:47 PM, "Eric I." <rubytraining@gmail.com> wrote:

> On Nov 12, 5:59 pm, Tarek Other <cashew...@yahoo.com> wrote:
>
>>
>> i.e.) I want to know if there is a way to call the block such that it
>> knows or has access to all the local variables of the caller without
>> having to pass those local variables in.
>
> Hi Tarek,
>
> Yes, this is the standard behavior of blocks.  Blocks are closures,
> which means that they have access to the surrounding environment.
>
> For example, this code works just fine, even though "y" is a local
> variable used set outside the block and used inside the block:
>
> ====
>
> def method1(&block)
>  0.upto(12) do |v|
>    yield v
>  end
> end
>
> def method2(y)
>  method1 do |z|
>    puts "#{y} * #{z} = #{y * z}"
>  end
> end
>
> puts "Let's do the 3 times tables:"
> method2(3)
>
> ====
>
> I hope that helps,
>
> Eric
>
> ====
>
> Are you looking for on-site Ruby or Ruby on Rails training
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>
>