From: Mark Slagell <ms@...>
Date: 2001-08-16T00:15:23+09:00
Subject: [ruby-talk:19788] 2 iterator questions

I'm looking at some code in the FAQ (section 5) illustrating the
relationship between blocks and proc objects.  Two questions come to mind:

-------------------------------------
1. "An iterator is a method which accepts a block or a Proc object."  How
to accept a proc object?  I can't come up with working syntax.  This
chokes, anyway:

  pr = proc {|x| x+1}
  [1,2,3].each pr

Since the error indicates that pr is being treated as a paramater, I tried
this

  [1,2,3].each() pr

and got a parse error.  On the other hand there's no problem sending a
proc object through the regular argument list:

  def iter(aproc)
    aproc.call 17
  end

  iter pr   #->  18

Is that what is meant by saying iterators can accept proc objects?

-------------------------------------
2. The conversion of a block to a proc inside an iterator(sec. 5.3) is
interesting... I'm curious what use it might have though.  Any thoughts?

Thanks

  Mark