[Tcl-bugs] [ tcl-Bugs-219387 ] info locals seems not to work properly

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Bugs item #219387, was opened at 2000-10-26 06:12
Message generated for change (Comment added) made by phoinix77
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Category: 17. Commands I-L
Group: obsolete: 8.3.2
Status: Open
Resolution: Fixed
Priority: 8
Private: No
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Don Porter (dgp)
Summary: info locals seems not to work properly

Initial Comment:
OriginalBugID: 6131 Bug
Version: 8.3.2
SubmitDate: '2000-08-14'
LastModified: '2000-10-25'
Severity: MED
Status: UnAssn
Submitter: techsupp
OS: Linux-SuSE
OSVersion: SuSE 6.4
Machine: AMD K6
FixedDate: '2000-10-25'
ClosedDate: '2000-10-25'


Name:
Christian Eva

ReproducibleScript:
proc xloc {args} {
    global Defaults LikeDictionaries env L1
    global Dictionaries

    foreach m $args {
        set $m $m
    }

    puts "locals=[info locals]"

    set L1 [info locals]
    puts "L1=$L1"

    unset args

    foreach a [info locals {[a-zA-Z]?*}] {
        puts "a=$a"
        eval set v \$$a
        set Dictionaries($a) $v
    }
}

set L1 empty

xloc a aA b Ba ccc 

puts "L1=$L1"

parray Dictionaries
# end

bash-2.03$ tclsh8.0 localtest
locals=args m L1 a ccc b aA Ba
L1=args m L1 a ccc b aA Ba
a=L1
a=ccc
a=aA
a=Ba
L1=args m L1 a ccc b aA Ba
Dictionaries(Ba)  = Ba
Dictionaries(L1)  = args m L1 a ccc b aA Ba
Dictionaries(aA)  = aA
Dictionaries(ccc) = ccc
bash-2.03$ 

bash-2.03$ tclsh8.3 localtest
locals=args m L1 a Dictionaries ccc b aA Ba
L1=args m L1 a Dictionaries ccc b aA Ba
a=L1
a=Dictionaries
can't read "Dictionaries": variable is array
    while executing
"set v $Dictionaries"
    ("eval" body line 1)
    invoked from within
"eval set v \$$a"
    (procedure "xloc" line 18)
    invoked from within
"xloc a aA b Ba ccc "
    (file "localtest" line 25)
bash-2.03$

ObservedBehavior:
First I do not understand why "info locals" does list the global variables. It seems to lists them as soon as they are referenced in the procedure. 

Second: The example works in tcl8.0 but not in 8.3. If I put the line
    global Dictionaries

down into the foreach loop it works as a workaround:
    foreach a [info locals {[a-zA-Z]?*}] {
        global Dictionaries
        puts "a=$a"
        eval set v \$$a
        set Dictionaries($a) $v
    }

This is an extract out of a running program since 7.6. In 8.0 the error does not cause trouble but under 8.3 it crashes.

DesiredBehavior:
I would expect the varables listed in the global statement not to be
listed by "info locals" at all.





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Comment By: Christian Knoepfel Eva (phoinix77)
Date: 2008-08-29 16:51

Message:
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user_id=2176213
Originator: NO

Please close this ticket.

I was the original submitter of this ticket.
I understand the philosophy behind the behaviour as you explain it.
It is just annoying as we still have the mentioned program running on
8.0,
but I will eventually change it as we have the most of our programs now
converted to run on 8.5.

Christian Eva

----------------------------------------------------------------------

Comment By: Donal K. Fellows (dkf)
Date: 2008-08-29 15:20

Message:
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Originator: NO

I've no idea; I've forgotten everything about this bug that I ever knew.

At a guess, someone seems to be wanting [info locals] to not return linked
variables. If they want stuff that's been brought in by [upvar] but not by
[global], I don't want to know.

I have no plans to do anything about this bug. The world hasn't ended.

----------------------------------------------------------------------

Comment By: Don Porter (dgp)
Date: 2008-08-29 15:08

Message:
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Originator: NO


The doc change noted here (from a
2000-11-21 commit!) has been flagged
on comp.lang.tcl as incorrect.

Is there any recollection beyond
what's recorded here how that
change came about, and how it came
to be incorrect?


----------------------------------------------------------------------

Comment By: Donal K. Fellows (dkf)
Date: 2000-12-01 13:56

Message:
There is a difference when you consider passing in search patterns with
namespace qualifiers.  [info locals] only finds variables in the current
naming context, [info globals] only finds variables in the global naming
context, and [info vars] finds variables in either the current naming
context or any named one (with qualifiers added.)  The difference is
admittedly slight, but it is significant.  The current behaviour is also
correct and documented correctly.

----------------------------------------------------------------------

Comment By: Marc Ziegenhagen (mzi)
Date: 2000-12-01 12:19

Message:
I have the same problem and can't understand the differences between info
locals and info vars. In the release 8.3.2 there is not a difference.
Marc Ziegenhagen

----------------------------------------------------------------------

Comment By: Donal K. Fellows (dkf)
Date: 2000-11-15 14:58

Message:
[info locals] lists the variables that are visible in the current context. 
All [global] does is create a local alias for each named global variable
with the "same" name as the global variable (it doesn't work
quite like that if you put in namespace qualifiers, but that's a separate
story.)  This is not a bug, or certainly not a functional one.  Maybe a
documentation change would help instead?

----------------------------------------------------------------------

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