ns-load                 package:base                 R Documentation

Loading and Unloading Name Spaces

Description:

     Functions to load and unload namespaces.

Usage:

     attachNamespace(ns, pos = 2, dataPath = NULL)
     loadNamespace(package, lib.loc = NULL,
                   keep.source = getOption("keep.source.pkgs"),
                   partial = FALSE, declarativeOnly = FALSE)
     loadedNamespaces()
     unloadNamespace(ns)

Arguments:

      ns: string or namespace object.

     pos: integer specifying position to attach.

dataPath: path to directory containing a database of datasets to be
          lazy-loaded into the attached environment.

 package: string naming the package/name space to load.

 lib.loc: character vector specifying library search path.

keep.source: logical specifying whether to retain source. This applies
          only to the specified name space, and not to other name
          spaces which might be loaded to satisfy imports.

          For more details see this argument to 'library'. 

 partial: logical; if true, stop just after loading code.

declarativeOnly: logical; disables '.Import', etc, if true.

Details:

     The functions 'loadNamespace' and 'attachNamespace' are usually
     called implicitly when 'library' is used to load a name space and
     any imports needed.  However it may be useful to call these
     functions directly at times.

     'loadNamespace' loads the specified name space and registers it in
     an internal data base.  A request to load a name space that is
     already loaded has no effect.  The arguments have the same meaning
     as the corresponding arguments to 'library', whose help page
     explains the details of how a particular installed package comes
     to be chosen.  After loading, 'loadNamespace' looks for a hook
     function named '.onLoad' as an internal variable in the name space
     (it should not be exported).  This function is called with the
     same arguments as '.First.lib'.  Partial loading is used to
     support installation with the '--save' and '--lazy' options.

     'loadNamespace' does not attach the name space it loads to the
     search path.  'attachNamespace' can be used to attach a frame
     containing the exported values of a name space to the search path.
     The hook function '.onAttach' is run after the name space exports
     are attached.

     'loadedNamespaces' returns a character vector of the names of the
     loaded name spaces.

     'unloadNamespace' can be used to force a name space to be
     unloaded.  An error is signaled if the name space is imported by
     other loaded name spaces.  If defined, a hook function '.onUnload'
     is run before removing the name space from the internal registry.
     'unloadNamespace' will first 'detach' a package of the same name
     if one is on the path, thereby running a '.Last.lib' function in
     the package if one is exported.

Author(s):

     Luke Tierney

