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From: lennartb@lne.kth.se (Lennart Boerjeson @ KTH/LNE, The Royal Inst. of Tech.)
Newsgroups: comp.sys.handhelds
Subject: Re: BREAK and RETURN on the 48sx: where are they?
Message-ID: <00941516.C03464A0@lne.kth.se>
Date: 17 Dec 90 09:57:15 GMT
References: <8601@dog.ee.lbl.gov>
Sender: news@kth.se  (News Administrator)
Reply-To: lennartb@lne.kth.se (Lennart Boerjeson @ KTH/LNE, The Royal Inst. of Tech.)
Organization: KTH, Royal Institute of Technology, School of Electrical Engineering
Lines: 43

In article <8601@dog.ee.lbl.gov>, austern@ux5.lbl.gov (Matt Austern) writes:
>As far as I can tell, the HP 48 doesn't provide any way to break out
>of a loop in the middle (in C, break), and doesn't provide any way to
>return from a function anywhere but the end.  (in C, return).  Yes, I
>know that it's always possible to avoid using these if you put in an
>extra test or flag, but sometimes they are convenient.
>
>Am I missing something very basic?  Or if there really is no break or
>return, has anyone out there found a good kludge to simulate them?
>-- 
>Matthew Austern    austern@lbl.bitnet     Proverbs for paranoids, 3: If 
>(415) 644-2618     austern@ux5.lbl.gov    they can get you asking the wrong 
>                   austern@lbl.gov        questions, they don't have to worry
>                                          about answers.

I usually do that by surrounding the code I might want to break out of with
an IFERR. Then I can 'break' out with a DOERR call. E.g:

IFERR
... 
 DO
 ....
  ....
   ....
     "BREAK" DOERR
   ....
  ....
 UNTIL ... END
THEN
  IF ERRM "BREAK" SAME NOT THEN  @ Was it 'break' ? @
    ERRN DOERR                   @ No, resignal error @
  END
END


!++
! Lennart Boerjeson, System Manager
! School of Electrical Engineering
! Royal Institute of Technology
! S-100 44 Stockholm, Sweden
! tel: int+46-8-7907814
! Internet: lennartb@lne.kth.se
!--