Re: Euphoria features
----- Original Message -----
From: Everett Williams <rett at GVTC.COM>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Monday, November 15, 1999 11:34 AM
Subject: Re: Euphoria features
> On Mon, 15 Nov 1999 08:59:35 +0000, nieuwen at XS4ALL.NL wrote:
>
> >Lucius, goto's _are_ effective ..
> >One out of 10, maybe 15 algorithms I use, depends on flag variables to
jump out of multiple
> >levels of a loop. Now that's messy.
> >
>
> >Ralf Nieuwenhuijsen
>
> Ralf,
>
> Those flag variables, if named something explanatory provide status
> information that is most valuable, specifically in debugging or
influencing
> the code to be performed at the target of the goto. My favorite is a
> depth variable for recursive code.
A var you coded yourself, or the for/while vars? I addressed the for/while
vars earlier. You can do the tracing vars you write now, if you do, as you
do now.
>The other problem with goto, is that it
> is a tailless kite. It provides no pointer to it's source once it gets
where
> it is going.
Eu currently stores program flow, it can continue to do that, backtracing
that store as needed.
>I suspect that because of the violence done to block structures
> and the loss of state information(currently, in Euphoria, you are always
> in the main line, or in a procedure or function stack that leads back to
> the main line), the overhead alone will prevent the use of goto's if
> Robert is foolish enough to resurrect this long-dead canard for those
> who haven't learned how to structure their logic yet.
I know how to build up a huge pile of procedures, calling them as needed
with if statements, using global vars to pass back flags about whether to
call the next procedure, etc., and i consider that worse than any
block-scope-limited goto could ever be. It's more code, more overhead, and
harder to debug. I agree with Ralf on this one. Gimme a goto.
>By the way,
> routine_id() with call...call_back is a goto with many of the same
effects.
Routine_id() should be only setting a memory pointer before it is normally
set by the interpreter/compiler. No harm in that. In fact, if it's not done,
how can you have two functions call each other?
Kat
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