TIP #214: Add New Object Introspection Command

TIP #214: ADD NEW OBJECT INTROSPECTION COMMAND
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========
Version:      $Revision: 1.1 $
Author:       <usus_at_aladyn.de>
State:        Draft
Type:         Project
Tcl-Version:  8.5
Vote:         Pending
Created:      Tuesday, 24 August 2004
URL:          http://purl.org/tcl/tip/214.html
WebEdit:      http://purl.org/tcl/tip/edit/214
Post-History:

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ABSTRACT
==========

This TIP proposes the new *representation* subcommand to /info* which
returns the internal representation of a variable's contents.

RATIONALE
===========

Inspired by a posting on <URL:news:comp.lang.tcl> by Victor Wagner, I
considered a facility to obtain the internal representation of a the
value in variable to be useful.

* It further completes the Tcl introspection commands.

* It offers a method to check the type of a variable without
conversion.

* During the development process it is useful to detect/avoid
shimmering and its negative performance effects.

PROPOSED CHANGE
=================

Add the new subcommand *info representation* with the following syntax:

*info representation* /varName/

It returns the type of the variable /varName/ or an error, if

* /varName/ doesn't exist,

* /varName/ is an array and no index is provided,

* /varName/ is a scalar variable but an index is provided.

IMPLEMENTATION
================

A patch against Tcl8.4.6 is available
[<URL:http://sf.net/tracker/?func=detail&...p/tcl_announce/
Send administrivia to tcl-announce-request@mitchell.org
Tcl/Tk at http://tcl.tk/ ]]