is possible a variable goto or gosub?

is possible a variable goto or gosub? - Printable Version

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is possible a variable goto or gosub? - maeloterkim - 09-27-2021

Hi

in the original ZX spectrum basic you can do this

goto MyVariable or gosub MyVariable where this variable must be a line number

this way we can goto or gosub to diferents routines that are in diferents line numbers

but i tried this example with the compiler and says error: Syntax Error. Unexpected token 'MyRoutines' <ARRAY_ID>

This is the example you can try:

dim MyRoutines(2) as uInteger => { @MyRoutine1, _ '' address of my routine 1
                     @MyRoutine2, _ '' address of my routine 2
                    @MyRoutine3 _ '' address of my routine 3
}

dim myVariable as uByte = 1

gosub MyRoutines(myVariable)     '' you can try goto too

myLoop:
goto myLoop

MyRoutine1:
print "MyRoutine 1"
return

MyRoutine2:
print "MyRoutine 2"
return

MyRoutine3:
print "MyRoutine 3"
return

Is possible do something like that without a lot of ifs ?

I think i found a solution

The solution i found is this:

dim MyRoutines(2) as uInteger => { @MyRoutine1, _ '' address of my routine 1
@MyRoutine2, _ '' address of my routine 2
@MyRoutine3 _ '' address of my routine 3
}

dim myVariable as uByte = 0

poke uInteger (@pokeGosub1 + 1), MyRoutines(myVariable)

pokeGosub1:
gosub MyRoutine1

myLoop:
goto myLoop

MyRoutine1:
print "MyRoutine 1"
return

MyRoutine2:
print "MyRoutine 2"
return

MyRoutine3:
print "MyRoutine 3"
return

I do a poke with the routine direction just before the gosub

maybe you can implement this with the compiler

this way the behaviour is more like the original ZX spectrum Smile

RE: is possible a variable goto or gosub? - boriel - 09-28-2021

(09-27-2021, 01:50 PM)maeloterkim Wrote: Hi

in the original ZX spectrum basic you can do this

goto MyVariable or gosub MyVariable where this variable must be a line number

maybe you can implement this with the compiler

...

this way the behaviour is more like the original ZX spectrum

You don't need all of this. Use ON ... GOTO / ON GOSUB instead.

Code:
on myVariable gosub MyRoutine1, MyRoutine2, MyRoutine3

myLoop:

goto myLoop

MyRoutine1:

print "MyRoutine1"

return

MyRoutine2:

print "MyRoutine2"

return

MyRoutine3:

print "MyRoutine3"

return

Try this, and let me know if it works. Shy

RE: is possible a variable goto or gosub? - maeloterkim - 09-28-2021

(09-28-2021, 07:41 PM)boriel Wrote:
(09-27-2021, 01:50 PM)maeloterkim Wrote: Hi

in the original ZX spectrum basic you can do this

goto MyVariable or gosub MyVariable where this variable must be a line number

maybe you can implement this with the compiler

...

this way the behaviour is more like the original ZX spectrum

You don't need all of this. Use ON ... GOTO / ON GOSUB instead.

Code:
on myVariable gosub MyRoutine1, MyRoutine2, MyRoutine3 myLoop: goto myLoop MyRoutine1: print "MyRoutine1" return MyRoutine2: print "MyRoutine2" return MyRoutine3: print "MyRoutine3" return

Try this, and let me know if it works.

Yes it works

But i didnt found this ON .. GOTO OR GOSUB in the documentation ( https://zxbasic.readthedocs.io/en/docs/identifier/ )

maybe there is something or a lot more that we dont know Smile

RE: is possible a variable goto or gosub? - boriel - 09-29-2021

(09-28-2021, 09:56 PM)maeloterkim Wrote:
(09-28-2021, 07:41 PM)boriel Wrote:
(09-27-2021, 01:50 PM)maeloterkim Wrote: Hi

in the original ZX spectrum basic you can do this

goto MyVariable or gosub MyVariable where this variable must be a line number

maybe you can implement this with the compiler

...

this way the behaviour is more like the original ZX spectrum

You don't need all of this. Use ON ... GOTO / ON GOSUB instead.

Code:
on myVariable gosub MyRoutine1, MyRoutine2, MyRoutine3 myLoop: goto myLoop MyRoutine1: print "MyRoutine1" return MyRoutine2: print "MyRoutine2" return MyRoutine3: print "MyRoutine3" return

Try this, and let me know if it works.

Yes it works

But i didnt found this ON .. GOTO OR GOSUB in the documentation ( https://zxbasic.readthedocs.io/en/docs/identifier/ )

maybe there is something or a lot more that we dont know

Unfortunately (I checked yesterday) GOTO / GOSUB and IN documentation is lost (I moved the wiki long ago, some documents were not restored correctly). I'll put them back.

Thanks for reporting. If you find any other broken link, please let me know.