From: dblack@...
Date: 2006-07-12T02:00:24+09:00
Subject: Re: blocks and procs

Hi --

On Wed, 12 Jul 2006, Dark Ambient wrote:

> Just curious, I'm just learning about Procs, and have already looked at
> using blocks.
> Are they very close in the way they function.  It seems that way to me.
> Perhaps I'm wrong.
> Is one favoured above the other ?

They're different things.  A block is a syntactic construct, part of a
method call.  A Proc object is an object.

They are, however, closely related.  Using special argument syntax, a
method can turn the block supplied to it into a Proc:

   def meth(&block)
     # block is the Proc version of the block
     block.call  # etc.
   end

   meth { # this is the block }

Also, you can use Proc objects as block substitutes:

   meth &some_proc_object


David

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