From: Angel Martin <angel@...>
Date: 2004-05-20T00:29:43+09:00
Subject: Re: Arguments and formal variables

El mi�, 19-05-2004 a las 16:38, Robert Klemme escribi�:
> "Angel Martin" <angel@tyrex.mine.nu> schrieb im Newsbeitrag
> news:1084970490.26805.37.camel@tyrex.mine.nu...
> > In first place I sorprised with te behavior of formal variables inside a
> > metod or proc:
> 
> Why are you surprised?  Formal method / proc parameters and bound to some
> ruby instances on method invocation.  Whenever you assign to them from
> inside the method / proc, only this variable binding changes.  These
> variables are not aliases for any other variables.  

Because a C pointer view :-)

It seems to me that the arguments in method are new instances of the
container, I mean:
'a' outside is a pointer(in C) to the struct that hold the container of
ref to obj
'a' arguments is a pointer to a new struct which contains the same ref,

If assign (=) change the ruby ref of the container, but in the new scope
'a' is now a container.dup, I can't change the ref outside :-(

The sentence "In Ruby all object are passed be reference" give me a
'pointer view' of this.

The Array wraping values IHMO seems to be a little Ugly, but simple
enought to me.

> If they would be, you
> could not do this, because initialization is done from an expression
> evaluation and not a variable:
Please, can you explain a litle more about?
What is the difference in initialization between a expresion evaluation
and a variable if expresion return some type of value.

Thanks,
  Angel