Re: [TCLCORE] handling loops interruption within a 'try'

[Csaba N. <csa...@t-...>]

The following *restructured* code works for me as expected:

proc p {}
     while {[some_expensive_query]} {

         # ....

         if {[some_intervening_condition]} {
             return -code break ;# -level 1
         }

         # ....
     }
}

try {
     p
} on break {} {
     puts " ---- break ----"
     puts "Loop interrupted by break"
} on ok {} {
     puts "Loop completed normally"
} finally {
     puts "done"
}


Am 01.04.25 um 07:27 schrieb Massimo Manghi:
> I apologize for (ab)using this mailing list to ask a question that maybe 
> has a trivial answer.
> 
> I just can't have the 'on break' clause be triggered in a loop 
> controlled by a 'try' construct
> 
> try {
>      while {[some_expensive_query]} {
> 
>          # ....
> 
>          if {[some_intervening_condition]} {
>              return -code break -level 0
>          }
> 
>          # ....
>      }
> } on break {} {
>      puts " ---- break ----"
>      puts "Loop interrupted by break"
> } on ok {} {
>      puts "Loop completed normally"
> } finally {
>      puts "done"
> }
> 
> and you have a normal termination even though the loop was interrupted 
> prematurely by [some_intervening_condition]
> 
> I can get what I want by raising an exception with 'throw' and then 
> using the trap clause which allows extra control over the cause of the 
> exception (-errorcode receives no special treatment unless the option - 
> code error is passed) but what is the purpose of the 'on break' clause 
> if it's not handling a break?
> 
>   -- Massimo
> 
> 
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-- 
Csaba Nemethi  https://www.nemethi.de  mailto:csa...@t-...