Re: HP67/97/41 translator


<gerard.evrard@xxxxxxx> schrieb im Newsbeitrag
news:1180023728.587561.39400@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
The main problem remains GTO ... You can't translate it in easy way...

...one of the thing that I most like in (User)RPL is the lacking of
GOTO, a superflous ...

You like to feel pain ? There is a name for this disease.

I prefer powerful languages like :
RPN (has GOTO),
Pascal (has GOTO),
C++ (has GOTO),
or even BASIC (has GOTO).
Is there a scheme here ?
I decide what I want and the language provides the support.

As for RPL, you can't even break out of a loop. Yuck.

This is NOT correct.

Of course you can 'break out' of a loop, if you really want to.
JHM shows how to do it in UserRPL,
I'll indicate how to do it in SysRPL.

Consider the following code snippet:

DO
:: ..some_code..

..test_condition..
case ExitAtLOOP

..some_other_code..
;
LOOP

If ..test_condition.. returns TRUE,
the ExitAtLOOP word will be evaluated.
ExitAtLOOP is the same as 'ZEROISTOPSTO',
in other words : Loop end has been reached.

This is the clean and supported way to terminate a loop
at any time.

You can also exit a loop using an error condition.

You could even exit a loop using return stack manipulating words,
but that would indicate a code design problem,
not a limitation of the language...

Please refer to RPLMAN.DOC for more info on this topic.

BTW: As mentioned in my earlier post, even SysRPL has a GOTO ;-)

Don't get me wrong:
When programming an HP-41, be it RPN or (in most cases) ML,
you'll need GO jumps.

However, RPL isn't RPN nor BASIC nor Pascal .
It's RPL, a combination of FORTH and LISP.

To get the most out of your HP-48 based machine,
it's best to use the language which is suited best for the platform,
and that's RPL, where you simply don't need GO jumps.

HTH

Raymond



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