Re: Local vs global variables in ADA

[Dennis Lee Bieber <wlfraed@ix.netcom.com>]

john mann fed this fish to the penguins on Wednesday 06 November 2002 
06:40 am:

> Dennis Lee Bieber <wlfraed@ix.netcom.com> wrote in message
> news:<p0u9qa.4p3.ln@beastie.ix.netcom.com>... <snip>
>>         And /neither/ structure really handles the form where you
>>         need a bit
>> of processing before you can do the test...
>> 
>> 
>>         loop
>>                 preprocessing which sets flag
>>             exit when <cond>
>>                 other processing
>>         end loop.
>> 
> 
> 
> Well, you could use a function to get the while test value.
> Couldn't you?

        Most of my experience is in FORTRAN, avoiding vendor specific 
extensions, but still... writing whole function WITH SIDE-EFFECTS and 
calling overhead to change

        read(unit,format, iostat=ios) v1, v2, v3
  10    if (ios .ne. EOF_VALUE) then
                other processing
                read(unit,format, iostat=ios) v1, v2, v3
        goto 10
        endif

into
        integer function funcwithsideeffects(a1,a2,a3)
        read(unit,format, iostat=is) a1, a2, a3
        funcwithsideeffects = is
        return

        ...

  10    if (funcwithsideeffects(v1,v2,v3) .ne. EOF_VALUE) then
                other processing
        goto 10
        endif

        
        Would have gotten jeers from code inspections at my former employer. 
Especially as I'd have to document/justify the creation of those 
snippet functions.

        As it is, I only used "goto" in constructs where the destination was 
before the goto (as anyone reading the code should have seen the target 
already, and not have to search). This is why I did not fake the Ada 
loop/exit when/end loop in FORTRAN... If I had, the result would have 
looked like:

   10   continue
                read(unit,format, iostat=ios) v1, v2, v3
                if (ios .eq. EOF_VALUE) goto 20
                other processing
        goto 10
   20   continue


        Granted, Ada's I/O system is such that creating a procedure to 
consolidate the three variable reads into one is feasible -- but again, 
to put the status return into it still requires a function with 
side-effects if one wants to use while ... loop/end loop




--  
 > ============================================================== <
 >   wlfraed@ix.netcom.com  | Wulfraed  Dennis Lee Bieber  KD6MOG <
 >      wulfraed@dm.net     |       Bestiaria Support Staff       <
 > ============================================================== <
 >        Bestiaria Home Page: http://www.beastie.dm.net/         <
 >            Home Page: http://www.dm.net/~wulfraed/             <