From: "David A. Black" <dblack@...>
Date: 2008-08-13T06:33:14+09:00
Subject: Re: Ruby 1.9: What to Expect by Sam Ruby @ OSCON 2008 Slide Deck Adapted S6/S9 (Single-Web Page) Version

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Hi --

On Wed, 13 Aug 2008, I=F1aki Baz Castillo wrote:

> El Martes, 12 de Agosto de 2008, I=F1aki Baz Castillo escribi=F3:
>
>> the result is the same (but true, if I run your code in 1.8 and 1.9 resu=
lt
>> is different, but I don't understand which is the difference between you=
r
>> code and mine).
>
> Maybe the difference occurs when the variable is passed to the block as
> parameter ( {|a| ..} ) ?

Yes. If it's a block parameter, it will not clobber the outer
variable. If you just use a variable (non-parameter) in the block,
then it is the same as the outer variable. (That's how blocks work as
closures.)

If you want to use a non-parameter inside a block and have it not
clobber an outside variable, you can declare it as a local variable by
putting it after a semi-colon in the parameter list:

   {|x,y,z;a| a =3D 1 }    # a is not bound to any block args but is
                         # local to the block


David

--=20
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