gosub inside If ... endif

[marc_256]

Hi,

I'm using this simplified code

Code: Select all

Value = 2
  Select Value
    Case 1
      Debug "Value = 1"
      Gosub DrawValue1
    Case 2 
      Debug "Value = 2"
      Gosub DrawValue2
    Case 20 
      Debug "Value = 20"
      Gosub DrawValue20
    Default
      Debug "I don't know"
  EndSelect

this seems not to work,
so, I tried this one ...

Code: Select all

Value = 2
  If Value = 1
    Gosub DrawValue1
  ElseIf Value = 2
    Gosub DrawValue2
  ElseIf Value = 3
    Gosub DrawValue3
  Else
    Debug "I don't know"
  EndIf    

  End


DrawValue1:
    Debug "Value = 1"
    Return

DrawValue2:
    Debug "Value = 2"
    Return

DrawValue3:
    Debug "Value = 3"
    Return

same problem, PB is blocking.

- WIN 8.1 x64
tested with
- PB 5.45 LTS x64
- PB 5.61 Final x64

thanks,
marc,

[Demivec]

Both codes work fine for me with no errors or faults.

- WIN 8.1 x64
tested with
- PB 5.45 LTS x64
- PB 5.61 Final x64

I used this modifed version of the incomplete code sample containing the Select/Case method:

Code: Select all

Value = 2
  Select Value
    Case 1
      Debug "Value = 1"
      Gosub DrawValue1
    Case 2 
      Debug "Value = 2"
      Gosub DrawValue2
    Case 3 
      Debug "Value = 3"
      Gosub DrawValue3
    Default
      Debug "I don't know"
  EndSelect
 
  End
  
  DrawValue1:
    Debug "Value = 1"
    Return

DrawValue2:
    Debug "Value = 2"
    Return

DrawValue3:
    Debug "Value = 3"
    Return

[marc_256]

Hi Demivec,

thanks for testing,
it seems that my (very big) program have some bugs ?
It works fine for 10 loops in the If ... end if loop,
and then PB stops.

strange, probably one of my bugs ...

Is it allowed to use gosub inside select ...endselect and if ... endif loops ?

marc,

[Bisonte]

Another approach, to "simulate" the OnGoto and OnGosub commands of older basic's...
Without stack problems...

Code: Select all

Prototype proto_none() ; Declare your Procedure with Parameters

Structure struct_callprocs ; set it into a structure
  Go.proto_none  
EndStructure

; your procedures
Procedure DrawValue1() 
  Debug "Value = 1"
EndProcedure
Procedure DrawValue2()
  Debug "Value = 2"
EndProcedure
Procedure DrawValue3()
  Debug "Value = 3"
EndProcedure

; Declare an array
Global Dim DrawValues.struct_callprocs(3)

; Set the adresses of the procedures to the array
DrawValues(1)\Go = @DrawValue1()
DrawValues(2)\Go = @DrawValue2()
DrawValues(3)\Go = @DrawValue3()

; Let the show begin ....
Value = 1

If Value > 0 And Value <= ArraySize(DrawValues())
  DrawValues(Value)\Go()
Else
  Debug "Don't know"
EndIf

Thanx to Stargate, who shows me this way years ago.

[cas]

Rewrite your code to use procedures and macros instead of goto/gosub. There is nothing that you can not do with procedures and macros but can with goto/gosub. I can not think of any goto/gosub advantage. Ok, maybe code readability in some cases. But you can always name your procedure or macro gosub_DrawValue() in these rare cases.

[marc_256]

Hi Bisonte,
thanks for your help,
I rewrote my program with goto's in place of gosub's
and all works well,
so, it seems you are right it seems to be a problem with gosub return address. (? stack)

Hi cas,
well I'm programming for a long time this way,
and never had problems till this morning.
I must say that I just upgraded PB to PB 5.45F LTS x64 and 5.61F x64

to all,
- is there someone who knows how deep the gosub nesting may be in PB (levels)
- how big is the stack used by PB ?
- and can I set this stack memory size myself ?

tanks,
marc

[marc_256]

I think I found some errors in my programming,

http://www.purebasic.com/documentation/ ... thers.html
and
http://www.purebasic.com/documentation/ ... tinue.html

I gone a read some stuff about BREAK and CONTINUE first

marc,