| ns-load {base} | R Documentation |
Functions to load and unload namespaces.
attachNamespace(ns, pos = 2, dataPath = NULL, depends = NULL)
loadNamespace(package, lib.loc = NULL,
keep.source = getOption("keep.source.pkgs"),
partial = FALSE)
requireNamespace(package, ..., quietly = FALSE)
loadedNamespaces()
unloadNamespace(ns)
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. |
depends |
|
package |
string naming the package/namespace to load. |
lib.loc |
character vector specifying library search path. |
keep.source |
Now ignored except during package installation.
For more details see this argument to |
partial |
logical; if true, stop just after loading code. |
quietly |
logical: should progress and error messages be suppressed? |
... |
further arguments to be passed to |
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 namespace and registers it in
an internal data base. A request to load a namespace when one of that
name 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 namespace (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 --lazy option.
loadNamespace does not attach the namespace it loads to the
search path. attachNamespace can be used to attach a frame
containing the exported values of a namespace to the search path (but
this is almost always done via library). The
hook function .onAttach is run after the namespace
exports are attached.
requireNamespace is a wrapper for loadNamespace
analogous to require that returns a logical value.
loadedNamespaces returns a character vector of the names of
the loaded namespaces.
unloadNamespace can be used to attempt to force a namespace to
be unloaded. If the namespace is attached, it is first
detached, thereby running a .Last.lib function
in the namespace if one is exported. Then an error is signaled if the
namespace is imported by other loaded namespaces, and the namespace
is not unloaded. If defined, a hook function .onUnload
is run before removing the namespace from the internal registry.
See the comments in the help for detach about some
issues with unloading and reloading namespaces.
attachNamespace returns invisibly the package environment it
adds to the search path.
loadNamespace returns the namespace environment, either one
already loaded or the one the function causes to be loaded.
requireNamespace returns TRUE if it succeeds or
FALSE.
loadedNamespaces returns a character vector.
unloadNamespace returns NULL, invisibly.
Luke Tierney and R-core