[vtkusers] tlcTK problems

[Christian Poecher]

For Tcl questions you'd better try the newsgroup comp.lang.tcl.
The problem with your code is, that the scope of variable a is just
crea. the line "global a" does exactly nothing. You must declare a
outside of the vars, if you want to work with globals.
The second error is, that you need a line "global a" in scrivi, to
access the var a.
I'd recommend reading the tcl-man entry for global for details on scope
of variables.
The corrected code is:
 
 proc crea {} {
 global a
 set a 4
 }
 
 proc scrivi {} {
 global a
 puts stdout $a
 }
 
 wm withdraw .
 
 set a init
 crea
 scrivi

Giancarlo Amati schrieb:
> 
> Hi everybody, I know that this is a Vtk mailing list, but I will disturb
> you for a tcl problem that concerning execution of tcl procedure; I have
> the following code:
> 
> proc crea {} {
> global a
> set a 4
> }
> 
> proc scrivi {} {
> puts stdout $a
> }
> 
> wm withdraw .
> 
> crea
> scrivi
> 
> the tcl interpreter give me the followind error:
> 
> Error in startup script: can't read "a": no such variable
>     while executing
> "puts stdout $a"
>     (procedure "scrivi" line 2)
>     invoked from within
> "scrivi"
>     (file "scrivi.tcl" line 13)
> 
> it seems that tcl interpreter executes scrivi procedure before crea
> procedure. Why? isn't tcl a sequential iterpreter?
> Any idea how to executer crea procedure before the second one?
> 
> Thank you very much.
> 
> Best regards,
> Giancarlo
> 
> ----------------------------------------
> dott. Giancarlo Amati                  |
> (amati at ira.cnr.it)                     |
>                                        |
> National Research Council              |
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Christian Poecher                      mailto:poecher at icom-consulting.de
ICOM GmbH   					Phone: +49 241 9367-1554
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