From: SonOfLilit <sonoflilit@...>
Date: 2007-02-18T21:05:29+09:00
Subject: Re: exit in a bloc DRY way...

A google turns up this:

In Ruby, break exits the block with value "nil". The caller must check
after each closure call to see if the value returned was "nil", and
break itself, if necessary. A side effect is that you can't return
"nil" from a block without terminating the calling structure. (As it
happens, this is almost always acceptable.)

Use IRB to figure if indeed the standard methods that accept blocks do
this checking.

contact.each {|c|  nb -= 1; exit;  if c.from == parameter } # the
second ; is definitely wrong

Perhaps you meant:

contact.each {|c| if c.from == parameter; nb -= 1; break; end }

Well, if each is defined and the Enumerable mixin is mixed in (it
usually is), you get #find for free, so:

$ ri Enumerable#find
-------------------------------------------------------- Enumerable#f
ind
     enum.detect(ifnone = nil) {| obj | block }  => obj or nil
     enum.find(ifnone = nil)   {| obj | block }  => obj or nil
---------------------------------------------------------------------
---
     Passes each entry in _enum_ to _block_. Returns the first for wh
ich
     _block_ is not +false+. If no object matches, calls _ifnone_ and
     returns its result when it is specified, or returns +nil+

        (1..10).detect  {|i| i % 5 == 0 and i % 7 == 0 }   #=> nil
        (1..100).detect {|i| i % 5 == 0 and i % 7 == 0 }   #=> 35


So how about:


nb = -1 if contact.find{|c| c.from == parameter }

?

This seems good.

Plug: Have a look at the adopt-a-newbie thread


Aur Saraf

On 2/18/07, Josselin <josselin@wanadoo.fr> wrote:
>  I wrote this code that's running well..
>            origin = false
>            contact.each {|c|  origin = true  if c.from == parameter }
>            nb -= 1 if origin
>
> is there any way to write it in one line ?  (exiting from the bloc when
> the condition is true)
> something like :
>            contact.each {|c|  nb -= 1; exit;  if c.from == parameter }
>
> tfyl
>
> joss
>
>
>
>