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)
