From: "Gerardo Santana Gómez Garrido" <gerardo.santana@...>
Date: 2008-05-04T02:59:15+09:00
Subject: Re: Why there is not "replace" method for Fixnum?

On Sat, May 3, 2008 at 12:39 PM, Iñaki Baz Castillo <ibc@aliax.net> wrote:
> Hi, using String#replace I can "simulate" a pointer (thanks to David A. for
>  the explanation):
>
>   a = "orignal a value"
>   b = a
>   b = "new value"
>   a
>   => "original a value"
>   b
>   => "new value"
>
>  This is obvious: after the new assigment of "b" it points to a different
>  object.
>
>  So I can use "replace":
>
>   a = "orignal a value"
>   b = a
>   b.replace "new value"
>   a
>   => "new value"
>   b
>   => "new value"
>
>
>  But Fixnum has not this method "replace", neither Float. Doesn't make sense
>  any primitive Ruby Class having this "replace" method instead of just one of
>  them?

Strings are mutable. Neither Fixnum or Float are; they are immediates.
Which means that you can alter the content of a String object, because
it's actually a pointer to data, while a Fixnum object *is* its
content itself. This is done for performance I think.

-- 
Gerardo Santana