Gosub by string

[aurelCB]

Hi...
You probably know that is in Creative Basic possible to jump to
subroutine with string if subroutine name are prefixed by string sign $:
like this:

Code Select Expand

Def w1:window
def mysub:string
mysub="newsub"
'create main window
openWindow w1,0,0,500,400,@minbox,0,"MainGUI",&main
Setwindowcolor w1,rgb(220,220,220)
'--------------------------------------------------------
gosub $mysub


'---------------------------------------------------------
run=1
waituntil w1=0

end

'-------------------------------------------------------
sub newsub
move w1,20,20:print w1,"OK"
return
endsub

'------------------------------------------------------
Sub main
Select @class
Case @idclosewindow
closewindow w1
Case @idcreate
Centerwindow w1
ENDSELECT
RETURN
ENDSUB

But same program not work in EB/IWB.
Is there a way to do similiar thing in EB/IWB ?

Using this method we can avoid long select/case and directly jump to subroutine.
Any ideas ....?

[Brian]

Aurel,

If you have a SUB named "Aurel" it is enough in IWB just to call Aurel(), as in:

Aurel()

SUB Aurel
   Called from Aurel()
ENDSUB

Brian

[LarryMc]

Not sure what you are ultimately trying to do.

If you are wanting to call different routines at a single point in your program by setting a string to a value and then doing the call I suggest you look at the IWB Help file Language/Subroutines/Indirectly calling subroutines section.

And the indirect_functions.iwb example.

LarryMc

[LarryMc]

What Brian posted is also correct.
Your code modified where it works in IWB:

Code Select Expand

Def w1:window
'def mysub:string
'mysub="newsub"
'create main window
openWindow w1,0,0,500,400,@minbox,0,"MainGUI",&main
Setwindowcolor w1,rgb(220,220,220)
'--------------------------------------------------------
mysub()


'---------------------------------------------------------
run=1
waituntil w1=0

end

'-------------------------------------------------------
sub newsub
move w1,20,20:print w1,"OK"
return
endsub

'------------------------------------------------------
Sub main
Select @class
Case @idclosewindow
closewindow w1
Case @idcreate
Centerwindow w1
ENDSELECT
RETURN
ENDSUB

LarryMc

[aurelCB]

Brian i know this of course....
Yes Larry i want to call muliple subs from one point using string.
You probably see this simple example from CB.
I already look into this example but this works with adresses...

[aurelCB]

Maby i must be more clear.
So what i want to do is next:
Get sub name from hash table (dictionary) and use this string to call
subroutine.

[LarryMc]

Maby i must be more clear.
So what i want to do is next:
Get sub name from hash table (dictionary) and use this string to call
subroutine.

The only way I know of doing that is creating a SELECT block; unless you can store a pointer to a subroutine in your hash instead of a string.

LarryMc

[aurelCB]

Uff yes Larry you right there is no way like in CB .
Hmm i dont know but i think that that i can store string pointer in hash.
I will try...

[zaphod]

hello,
you need to store an array of pointers like that :

Code Select Expand


DECLARE fnTemplate

Def w1:window
def mysub[2] as pointer 'string
mysub[0]=&newsub
mysub[1]=&newsub1
'create main window
openWindow w1,0,0,500,400,@minbox,0,"MainGUI",&main
Setwindowcolor w1,rgb(220,220,220)
'--------------------------------------------------------
!<fntemplate>mysub[0]()
!<fntemplate>mysub[1]()

'---------------------------------------------------------
run=1
waituntil w1=0

end

'-------------------------------------------------------
sub newsub
move w1,20,20:print w1,"OK"
return
endsub

sub newsub1
move w1,20,40:print w1,"O0K"
return
endsub
'------------------------------------------------------
Sub main
Select @class
Case @idclosewindow
closewindow w1
Case @idcreate
Centerwindow w1
ENDSELECT
RETURN
ENDSUB


[aurelCB]

Helo zaphod ...
good idea but not work.
i recive error -> invalid function pointer in this two lines:

Code Select Expand

!<fntemplate>mysub[0]()
!<fntemplate>mysub[1]()

Your code looks logical to me but still dont work...

[LarryMc]

Change

Code Select Expand

def mysub[2] as pointer 'string
to

Code Select Expand

def mysub[2] as UINT 'pointer 'string

and it should work.

LarryMc

[aurelCB]

Not work with strings...
hash table (dict) need string not UINT.

[aurelCB]

so i look into CB source code and find do_gosub structure.
But i simply do not uinderstand how misterP solve this thing:

Code Select Expand

if(*k=='$')
        {
                if(!(cv=find_var(k+1))) return(0);
                k = (TEXT *)cv->mem;

maby this piece of code is not for this place but im curious how this thing work
in CB.heck ...this looks like adventage of interpreter over compiler

[aurelCB]

Well it seems that will work with tamplate.
Here is code which use hash table:

Code Select Expand

'by zapHod array of strings as template
DECLARE fn()
'create hash table (dictionary)
strHash=DICTCREATE (100)

Def w1:window
def mysub[2] as uint 'string
'set two uintegers
mysub[0]=&newsub
mysub[1]=&newsub1
'test
MESSAGEBOX 0,"Adrr:"+str$(mysub[0]),"Test sub adress!"

'fill hash with strings
DictAdd(strHash,"s0",str$(mysub[0]))
DictAdd(strHash,"s1",str$(mysub[1]))

'create main window
openWindow w1,0,0,500,400,@minbox,0,"MainGUI",&main
Setwindowcolor w1,rgb(220,220,220)
'--------------------------------------------------------
uint temp
string temp$

'get string from hash table
temp$ = DictLookup(strHash,"s1")
'check if is not empty
IF temp$ <> ""
'set temp variable with subroutine adress
temp=VAL(DictLookup(strHash,"s1"))
IF temp <> 0
'jump indirectly to subroutine
!<fn>temp()
ENDIF
ENDIF

'---------------------------------------------------------
run=1
waituntil w1=0

end

'-------------------------------------------------------
sub newsub
move w1,20,20:print w1,"OK"
return
endsub

sub newsub1
move w1,20,40:print w1,"O0K"
return
endsub
'------------------------------------------------------
Sub main
Select @class
Case @idclosewindow
closewindow w1
Case @idcreate
Centerwindow w1
ENDSELECT
RETURN
ENDSUB

I hope that this will be usefull for anyone of you which have program with
long select/case block .

[aurelCB]

Just for info...
I don't know that this things exists in old implementation of FORTH language.
his is called direct threaded code (DTC).
from wikipaedia:
To save space, programmers squeezed the lists of subroutine calls into simple lists of subroutine addresses, and used a small loop to call each subroutine in turn.

[billhsln]

I am not 100% sure, but take a look at Indirectly calling subroutines, in the User's Guide.  It sounds like what you are looking to do.

Bill

[aurelCB]

Bill problem is solved and work fine