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Re: Bug in namespaces in 9.1?

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On 22/03/2026 19:13, Harald Oehlmann wrote:
> Am 22.03.2026 um 15:09 schrieb Simon Geard:
>> I've had a couple of scripts which work fine in 8.6 but fail in 9.0
>> and 9.1 Below is a small program that exhibits this change of behaviour:
>>
>> namespace eval GUI {
>>
>>      variable x_counter 1
>>
>>      proc create {} {
>>          puts "\tGUI::create => $GUI::x_counter"
>>      }
>> }
>> puts "Tcl patchlevel = [info patchlevel]"
>> puts "\tGUI exists = [namespace exists GUI]"
>> puts "\tGUI::x_counter exists = [info exists GUI::x_counter]"
>> puts "\tx_counter = $GUI::x_counter"
>>
>> if {[catch {GUI::create} err]} {
>>      puts "\t***Error: $err"
>> } else {
>>      puts "\t*** Success ***"
>> }
>>
>> Output:
>> Tcl patchlevel = 8.6.13
>>          GUI exists = 1
>>          GUI::x_counter exists = 1
>>          x_counter = 1
>>          GUI::create => 1
>>          *** Success ***
>>
>> Tcl patchlevel = 9.0.0
>>          GUI exists = 1
>>          GUI::x_counter exists = 1
>>          x_counter = 1
>>          ***Error: can't read "GUI::x_counter": no such variable
>>
>> Tcl patchlevel = 9.1a1
>>          GUI exists = 1
>>          GUI::x_counter exists = 1
>>          x_counter = 1
>>          ***Error: can't read "GUI::x_counter": no such variable
>>
>>
>> To me this looks like a bug since the variable exists and it'd be
>> really strange for a variable to exist that causes a crash when used.
>>
>> Thanks for any help.
>>
>> Simon
>>
> 
> Dear Simon,
> this is intended. You are using a miss-behaviour of 8.6, that it
> searches a variable not starting with "::" in the global namespace, if
> it is not found in the current namespace.

Was that 8.6 behaviour intended at the time by its implementer,
reviewers and enjoyed for its utility by scripters at the time or almost
completely disregarded?

What are the reasons for the choice to search the toplevel or not? I
recall that searching top-level namespaces in most scripting languages
with tcl-namespace-like features is desirable to facilitate migrating
first approximation scripts to more structured expressions.

Is it only a mis-behaviour by today's tcl developers' judgement but
desirable by other days' developers' judgement?


-- 
Tristan Wibberley

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Thread

Bug in namespaces in 9.1? Simon Geard <simon@whiteowl.co.uk> - 2026-03-22 14:09 +0000
  Re: Bug in namespaces in 9.1? Harald Oehlmann <wortkarg3@yahoo.com> - 2026-03-22 20:13 +0100
    Re: Bug in namespaces in 9.1? Simon Geard <simon@whiteowl.co.uk> - 2026-03-22 20:17 +0000
      Re: Bug in namespaces in 9.1? Emiliano <emiliano@example.invalid> - 2026-03-23 02:02 -0300
        Re: Bug in namespaces in 9.1? Harald Oehlmann <wortkarg3@yahoo.com> - 2026-03-23 10:16 +0100
    Re: Bug in namespaces in 9.1? Tristan Wibberley <tristan.wibberley+netnews2@alumni.manchester.ac.uk> - 2026-03-22 22:54 +0000

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