Tcl7.6 User Commands Man Page -- import (n)
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NAME

import - change the "import" list for a namespace

SYNOPSIS

import option ?arg arg ...?

DESCRIPTION

The import command is used to query or modify the import list for the current namespace context. Command, variable and namespace names are sought first in the current namespace context, then in all imported namespaces. This means that commands/variables can be referenced in an imported namespace without the usual namespace qualifiers. When a namespace is added to the import list, it acts as if it were a part of the namespace that imports it.

By default, each namespace imports its parent. This allows commands and variables at the global scope to be accessed transparently in child namespaces. Frequently-used libraries can also be added to the import list, but it is a good idea to import namespaces sparingly. If each namespace imported all of the others, there would be very little advantage to using namespaces.

By default, namespaces are imported in a "public" mode. This means that public commands/variables can be accessed transparently, but protected and private elements remain hidden. Namespaces can also be imported in a "protected" mode. This means that public and protected commands/variables can be accessed transparently, but private elements remain hidden. There is no way to import in a "private" mode, so private elements always remain hidden from other namespaces.

The option argument determines what action is carried out by the command. The legal options (which may be abbreviated) are:

import add name ?name...? ?-where pos...? Adds one or more namespace name references to the import list in the current namespace context. Each name reference may be a namespace name, or a list with two elements: the first element is the namespace name, and the second is the import protection level, either "public" or "protected".

The -where flag can be used to specify where the list of name's should be added in the existing import list: -after pos ?pos...?
Namespace name's are inserted after the position of namespace pos on the list. If more than one pos namespace is specified, the name's are inserted after the pos nearest the end of the list.

-before pos ?pos...?
Namespace name's are inserted before the position of namespace pos on the list. If more than one pos namespace is specified, the name's are inserted before the pos nearest the start of the list.

import all ?name?
Returns the namespace search path used for command/variable resolution in namespace name, or in the current namespace context if name is not specified. This is the list of namespaces found by starting at the target namespace, and following its tree of import references. Each element on the return list is itself a list containing a namespace name and its import protection level (public or protected).

import list ?importList?
Returns the import list in the current namespace context. Each element on the return list is itself a list containing a namespace name and its import protection level (public or protected). If a new importList is specified, then the import list is set to this. The elements of importList can be simple namespace names or two-element lists with a namespace name and its import protection level.

import remove name ?name...?
Removes one or more namespace name's from the import list in the current namespace context. Each name reference can be simple namespace name or a two-element list with a namespace name and its import protection level.

KEYWORDS

namespace, import, private, protected, public

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