Subj : Translating CASE from BAS
To   : Mark Lewis
From : Mike Luther
Date : Sat Feb 10 2001 04:32 am

Yur are precisely correct Mark

 ml> one of the things i was thinking about while writting the above was 
 ml> 'program efficiency'... in some situations this can be 
 ml> important...

 ml> if switch case is faster then if/then/else, then 
 ml> 'converting' to single value for that purpose once is 
 ml> a necessary evil until such time as one gets the 
 ml> chance to rework that section...

 ml> thinking about situations where the switch case stuff 
 ml> may possibly be executed hundreds of times a second vs 
 ml> if/then/else trees running hundreds of times a 
 ml> second...

 ml> == example ==
 ml>   red    == 1;
 ml>   blue   == 2;
 ml>   yellow == 3;

 ml> procedure routine1;
 ml> {
 ml>   input "what's your color?",color$;
 ml>   if color$ = "red" then color == red
 ml>     else if
 ml>       color$ = "blue" then color == blue
 ml>         else if
 ml>           color$ = "yellow" then color == yellow;
 ml> }

 ml> procedure routine2;
 ml> {
 ml>   case color of
 ml>    red : do_red_routine;
 ml>    blue : do_blue_routine;
 ml>    yellow : do_yellow_routine;
 ml> }

 ml> procedure routine3;
 ml> {
 ml>   case color of
 ml>    red : do_red_routine2;
 ml>    blue : do_blue_routine2;
 ml>    yellow : do_yellow_routine2;
 ml> }

 ml> {
 ml>   routine1;
 ml>   while 1==1 do
 ml>   {
 ml>     routine2;
 ml>     routine3;
 ml>   }
 ml> }
 ml> == end of example ==

Plus the worst of the Weevil's is that INSTR routines in BASIC, as most 
recently written are terribly fast from the way the assembler is coded that the 
modern compilers use!

As well, if, as in my case, go-no/go decisions are expected in real-time to 
literally half-second do-it or don't-do-it decisions, you are comparing COMM 
port I/O in real time against networked stored data from the hard disk,record 
lock withstanding, in the middle of it all!

What really makes it so intriquing to work with this stuff in OS/2, even in 
DOS-VDM's, is that the absolutely superb disk caching and HPFS file system 
begins to make what you are illustrating absolutely crucial in determining a 
fair shot at system-wide response time optimization!

There is this superb joke about the two boll weevils!  The 40# boll weevil eats 
twice as much cotton as the 20# boll weevil!  Therefore, when you kill each 
with a double barrel 12 gauge, you fall on your knees and say, "Thank you Lord, 
for teaching me the lesser of two weevils!  I've got seed left!"

Not with OS/2.  There is this voice from above that booms, "Sorry, your cotton 
was already gone by the time you got that Ithica!  Next time get down your 
Browning!   Make love, not war!"


Chuckle.


Mike @ 117/3001

--- Maximus/2 3.01
 * Origin: Ziplog Public Port (1:117/3001)

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