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Ticket UUID: 1577282
Title: TIP 283: ensemble's command resolution
Type: RFE Version: None
Submitter: msofer Created on: 2006-10-14 17:28:58
Subsystem: 21. [namespace] Assigned To: dkf
Priority: 7 High Severity:
Status: Open Last Modified: 2009-07-13 19:35:57
Resolution: None Closed By:
    Closed on:
Description:
[namespace unknown] should be able to follow [namespace
path] and [namespace unknown] lookup behaviour.

After application of [Patch 1577278], adding a line
  iPtr->lookupNsPtr = ensemblePtr->nsPtr;
just before the call to Tcl_EvalObjv in
NamespaceImplementationCmd enables this behaviour.

If the registered ensemble unknownProc returns a FQ
command as first element of the list, the resolution is
still global. If the name is not FQ, the resolution
will follow whatever rules the ensemble's namespace has
set in place.
User Comments: dkf added on 2009-07-13 19:35:57:
The NRE-enabled command dispatch function allows control over the command resolution context. Might be worth looking at whether this FRQ can be dealt with through that route.

msofer added on 2006-11-02 03:40:28:

File Added - 201011: tip283-1.patch

msofer added on 2006-11-02 03:40:27:
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user_id=148712

Updated patch that works in HEAD. It breaks test cmdAH-24.12
in a weird manner - by breaking autoloading of [clock scan].
The reason is exposed below; the problem with clock can be
fixed easily, but the wider problem may be more important.

*** DANGER ***

As the "fix" for [info level] in HEAD was reverted (Bug
1577492, previously called "let [info level] know ensemble
rewrites"), this new feature breaks nother usual idiom.

  'uplevel 1 [info level 0]' is NOT GUARANTEED to call the
present proc again

This is because:
(a) 'namespace ensemble' does not push a new frame
(b) 'namespace ensemble' calls by simple name (non qualified)
(c) 'info level 0' reflects only the actual call, ie, a
simple name

As an illustration, with this patch we get:

% namespace eval a {
    variable ct 0
    namespace ensemble create -map {x scan}
    proc scan args {
        variable ct
        if {$ct} {
            puts YES
            return
        }
        incr ct
        uplevel 1 [info level 0]
    }
}
% a x
wrong # args: should be "scan string format ?varName varName
...?"

msofer added on 2006-10-26 08:13:12:

File Added - 200065: tip283.patch

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Updated patch: code, docs, (incomplete) tests

msofer added on 2006-10-15 01:16:16:

File Added - 198173: eunknown.patch

msofer added on 2006-10-15 01:16:15:
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Patch for docs and tests attached

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