ns-lowlev                package:base                R Documentation

Low Level Name Space Support Functions

Description:

     Low level name space support functions.

Usage:

     loadingNamespaceInfo()
     saveNamespaceImage(package, rdafile, lib.loc = NULL,
                        keep.source = getOption("keep.source.pkgs"),
                        compress = TRUE)

Arguments:

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

 rdafile: name of file to save to.

 lib.loc: character vector specifying library search path.

keep.source: logical specifying whether to retain source.

compress: option passed to 'save'.

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'.  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'
     option.

     '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.

     'loadingNamespaceInfo' returns a list of the arguments that would
     be passed to '.onLoad' when a name space is being loaded. An error
     is signaled of a name space is not currently being loaded.

     'saveNamespaceImage' is used to save name space images for
     packages installed with '--save'.

Author(s):

     Luke Tierney

