From: Simon Krahnke <overlord@...>
Date: 2008-06-04T10:04:20+09:00
Subject: Re: Beginner help

* Justin To <tekmc@hotmail.com> (20:38) schrieb:

> What does this mean? What did I do wrong?

You are confusing blocks and procs. Every method can have a single
block, which can be tested by block_given? and called by yield. Procs
are Objects that have a call method.

There is no special syntax for defining a method that takes a block:

,----
| def a
|   yield 1
| end
| 
| a { | n | puts n }
| 
| def b(arg)
|   yield 1 + arg
| end
| 
| b(1) { | n | puts n }
`----

You can turn a block into a Proc:

,----
| def c(&block)
|   block.call 1
| end
| 
| def d(arg, &block)
|   block.call(1 + arg)
| end
`----

That's in fact what the proc method does:

,----
| p = proc { | n | puts n }
| p.call 1
`----

mfg,                   simon .... l