[Coco] [Color Computer] Question about BASIC coding guidelines

[Diego Barizo]

I did check that a while ago with some biggish program of mine, and 
there was an improvement.
Also noticed speed changes when doing
FOR A=0 TO 1 STEP 0
code that might change X or Y
IF X=Y THEN A=1
NEXT A

Instead of
90 code that might change X or Y
100 IF X<>Y THEN 90

But the difference is only notorious if the routine is after many code 
lines, because of the GOTO behavior explained before
Diego

Rogelio Perea wrote:
> I don't know if this would translate to the CoCo's Basic implementation: In
> order to speed up program execution time it was suggested to put all
> subroutines at the beginning of a program, that meant starting off with a 0
> GOTO XXX line sending control of the program to a bottom part where all
> variables were declared and then branch back to continue normal execution -
> all called subroutines within the running program would GOSUB to the initial
> lines of the code.
>
> This came from a TRS-80 Graphics book while discussing the implementation of
> an arcade game in Basic.
>
> Should probably toy with two versions of the same program this weekend and
> benchmark (if possible) any speed improvements/fallbacks between the two:
> one written in straightforward fashion and the other with the jump to
> declare + subroutines at the beggining.
>
>
>
> -=[ R ]=-
>
>
>
>
> On Wed, Oct 29, 2008 at 11:10 PM, James Diffendaffer<
> jdiffendaffer at yahoo.com>  wrote:
>
>    
>> As for searching through line numbers, Darren is right.  If the line
>> number is lower than the current one the interpreter starts at the
>> beginning.  If the line number is greater than the current one it
>> starts searching at the next line.  (Just so you know, there are some
>> BASICs out there that include the memory address of the lines being
>> called so no search occurs.  Not on the CoCo though.)
>>
>> There is one other important detail Darren left out.  Variables are
>> searched from start to end of the variable storage area so you want to
>> declare most used or time critical variables first.  Faster BASIC and
>> Other Mysteries or some similar book detailed this.
>>
>> Also, if you can keep a loop on a single line it's faster than spread
>> over multiple lines.  Actually, if you can reduce the number of lines
>> used by placing more on your lines the less searching has to take
>> place and the faster it takes place since code is stored in sort of a
>> linked list.  Less lines to search, the lest nodes in the list.
>>
>>      
>
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