# struct::map(3tcl) 1 struct ""

## Name

struct::map - Manage key/value maps

## Synopsis

- package require struct::map ?1?

- ::struct::map mapName
- mapName method ?arg arg ...?
- mapName get
- mapName names
- mapName set name ?value?
- mapName unset ?pattern...?

## Description

Provides a snit class whose instances manage a key/value map. In other words, an object wrapper around Tcl arrays.

## API

The main command provides construction of maps:

::struct::map mapName

  Creates a new, empty map with an associated global Tcl command whose name is mapName. It may be used to invoke various operations on the map. It has the following general form:

  mapName method ?arg arg ...?

    method and arguments determine the exact behavior of the command.

  If mapName is specified as %AUTO% a unique name will be generated by the package itself. The result of the command is the fully-qualified name of the instance command.

The following commands are possible for map objects:

mapName get

  Returns the entire map as a Tcl dictionary.

mapName names

  Returns the list of all keys known to the map, in arbitrary order.

mapName set name ?value?

  Sets key name to the specified value, if the value specified. Returns the value for the key. Throws an error if the key is not known.

mapName unset ?pattern...?

  Removes all keys matching at least one of the glob patterns from the map. If no pattern is specified all keys are removed. In other words, the default pattern is *. The result of the command is the empty string.

## Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category struct :: matrix 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.