Re: [OpenBIOS] Fwd: [PATCH] Adds local variable support to OpenBIOS.

[Programmingkid]

On Sep 1, 2012, at 7:51 PM, [e-mail] wrote:
> Message: 2
> Date: Fri, 31 Aug 2012 13:40:58 -0500
> From: Tarl Neustaedter 
> To: The OpenBIOS Mailinglist 
> Subject: Re: [OpenBIOS] Fwd: [PATCH] Adds local variable support to
>    OpenBIOS.
> Message-ID: 
> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
>
> On 2012-Aug-31 09:50 , Programmingkid wrote:
> > Are you saying my-variable is better than myVariable?
>
> Yes.

I have changed all my code from camelCase to hyphens.
> > How do global variables get you in trouble in recursion? Do you have 
> > an example?
>
> Not off-hand, we learn to avoid doing that. To construct one - let's 
> take a method doing recursion properly, and break it:
>
> \ Correct way, using stack manipulation
> : fibonacci ( fib -- return ) recursive
>    dup 2 >= if                 ( fib )
>       dup 1- fibonnaci         ( fib fib-1 )
>       swap 2 - fibonnaci       ( fib-1 fib-2 )
>       +                        ( fib )
>    then                        ( fib )
> ;
>
> \ Incorrect way - using variable "fib", which will get overwritten 
> during recursion
> 0 value fib;
> : fibonnaci ( fib -- return ) recursive
>    to fib \ to avoid stack manipulation
>    fib 2 < if
>       fib exit
>    then
>    fib 1- fibonnaci           ( fib-1)
>    fib 2 - fibonnaci          ( fib-1 fib-2 )
>                      ( fib )
>
> ;

There is nothing to worry about. All the global variables in my code are only used at compile- time - not during runtime.