namespacex - Namespace utility commands

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# namespacex(n) 0.3 tcllib "Namespace utility commands"

## Name

namespacex - Namespace utility commands

## Synopsis

- package require Tcl 8.5
- package require namespacex ?0.3?

- ::namespacex hook add ?namespace? cmdprefix
- ::namespacex hook proc ?namespace? arguments body
- ::namespacex hook on ?namespace? guardcmdprefix actioncmdprefix
- ::namespacex hook next arg...
- ::namespacex import fromns cmdname ?newname ...?
- ::namespacex info allchildren namespace
- ::namespacex info allvars namespace
- ::namespacex normalize namespace
- ::namespacex info vars namespace ?pattern?
- ::namespacex state get namespace
- ::namespacex state set namespace dict
- ::namespacex state drop namespace
- ::namespacex strip prefix namespaces

## Description

This package provides a number of utility commands for working with namespaces. The commands fall into four categories:

1. Hook commands provide and manipulate a chain of commands which replaces the single regular namespace unknown handler.

2. An import command provides the ability to import any command from another namespace.

3. Information commands allow querying of variables and child namespaces.

4. State commands provide a means to serialize variable values in a namespace.

## Commands

::namespacex hook add ?namespace? cmdprefix

  Adds the cmdprefix to the chain of unknown command handlers that are invoked when the namespace would otherwise invoke its unknown handler. If namespace is not specified, then cmdprefix is added to the chain of handlers for the namespace of the caller.

  The chain of cmdprefix are executed in reverse order of addition, i.e. the most recently added cmdprefix is executed first. When executed, cmdprefix has additional arguments appended to it as would any namespace unknown handler.

::namespacex hook proc ?namespace? arguments body

  Adds an anonymous procedure to the chain of namespace unknown handlers for the namespace.

  If namespace is not specified, then the handler is added to the chain of handlers for the namespace of the caller.

  The arguments and body are specified as for the core proc command.

::namespacex hook on ?namespace? guardcmdprefix actioncmdprefix

  Adds a guarded action to the chain of namespace unknown handlers for the namespace.

  If namespace is not specified, then the handler is added to the chain of handlers for the namespace of the caller.

  The guardcmdprefix is executed first. If it returns a value that can be interpreted as false, then the next unknown hander in the chain is executed. Otherwise, actioncmdprefix is executed and the return value of the handler is the value returned by actioncmdprefix.

  When executed, both guardcmdprefix and actioncmdprefix have the same additional arguments appended as for any namespace unknown handler.

::namespacex hook next arg...

  This command is available to namespace hooks to execute the next hook in the chain of handlers for the namespace.

::namespacex import fromns cmdname ?newname ...?

  Imports the command cmdname from the fromns namespace into the namespace of the caller. The cmdname command is imported even if the fromns did not originally export the command.

  If newname is specified, then the imported command will be known by that name. Otherwise, the command retains is original name as given by cmdname.

  Additional pairs of cmdname / newname arguments may also be specified.

::namespacex info allchildren namespace

  Returns a list containing the names of all child namespaces in the specified namespace and its children. The names are all fully qualified.

::namespacex info allvars namespace

  Returns a list containing the names of all variables in the specified namespace and its children. The names are all given relative to namespace, and not fully qualified.

::namespacex normalize namespace

  Returns the absolute name of namespace, which is resolved relative to the namespace of the caller, with all unneeded colon characters removed.

::namespacex info vars namespace ?pattern?

  Returns a list containing the names of all variables in the specified namespace. If the pattern argument is specified, then only variables matching pattern are returned. Matching is determined using the same rules as for string match.

::namespacex state get namespace

  Returns a dictionary holding the names and values of all variables in the specified namespace and its child namespaces.

  Note that the names are all relative to namespace, and not fully qualified.

::namespacex state set namespace dict

  Takes a dictionary holding the names and values for a set of variables and replaces the current state of the specified namespace and its child namespaces with this state. The result of the command is the empty string.

::namespacex state drop namespace

  Unsets all variables in the specified namespace and its child namespaces. The result of the command is the empty string.

::namespacex strip prefix namespaces

  Each item in namespaces must be the absolute normalized name of a child namespace of namespace prefix. Returns the corresponding list of relative names of child namespaces.

## Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category namespacex of the Tcllib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide unified diffs, i.e the output of diff -u.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.

## Keywords

extended namespace, info, namespace unknown, namespace utilities, state (de)serialization, unknown hooking, utilities

## Copyright

Copyright © 200? Neil Madden (http://wiki.tcl.tk/12790)
Copyright © 200? Various (http://wiki.tcl.tk/1489)
Copyright © 2010 Documentation, Andreas Kupries