Load an Rcpp Module into a Package
One or more calls to loadModule
will be included in the source
code for a package to load modules and optionally expose objects from
them. The actual extraction of the module takes place at load time.
loadModule(module, what = , loadNow, env =)
module |
The name of the C++ module to load. The code for the module should be
in the same package as the R call to |
what |
The objects to expose in the package's namespace corresponding to objects in the module. By default, nothing is exposed. The special value Otherwise, if supplied this should be a character vector, the elements being objects defined in the module. The vector can have a names attribute, in which case the non-empty names will be used to rename the objects; otherwise, the name of the object in the package namespace will be the same as the name in the C++ module. |
loadNow, env |
A logical flag to say whether the load actions should happen now, and the environment into which the objects should be inserted. When called from the source of a package, both of these arguments should usually be omitted. The value of The value of |
If the purpose of loading the module is to define classes based on C++
classes, see setRcppClass()
, which does the necessary
module loading for you.
When the module can be started (at namespace load time), the function
Module()
returns an environment with a description of
the module's contents. Function loadModule()
saves this as a
metadata object in the package namespace. Therefore multiple calls to
loadModule()
are an efficient way to extract different objects
from the module.
Requesting an object that does not exist in the module produces a warning.
Since assignments from the call cannot take place until namespace
loading time, any computations using the objects must also be
postponed until this time. Use load actions
(setLoadAction
) and make sure that the load action is
specified after the call to loadModule()
.
If the load takes place, the module environment is returned. Usually however the function is called for its side effects.
This function requires version 2.15.0 of R or later, in order to
use load actions, introduced in that version. See the note in the
help page for setRcppClass()
for details.
John Chambers
setRcppClass()
to avoid the explicit call.
loadRcppModules()
for a (deprecated) shotgun procedure to load all
modules.
## Not run: loadModule("yada", TRUE) # load all the objects from module "yada" ## End(Not run)
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