r - import all the functions of a package except one when building a package

Question

I'm building an R package (mypackage) that imports data.table and another package (let's call it myotherpackage).

Imports: data.table, myotherpackage is in the DESCRIPTION file of mypackage.

myotherpackage imports dplyr, which has several functions named like the data.table functions, so I get warnings like this everytime I load mypackage:

Warning: replacing previous import ‘data.table::first’ by ‘dplyr::first’ when loading ‘mypackage’

Is there a way to import all the functions of data.table except "first" for example? I'd then use data.table::first in the code if I need to use it. Or is there a better way to handle it? I'm trying to avoid the warning every time someones imports the package. Thank you!

Answer 1

The NAMESPACE file is somewhat flexible here, as described in Writing R Extensions.

The two main import directives are:

import(PACKAGE)

which imports all objects in the namespace into your package. The second option is to do specific imports using:

importFrom(PACKAGE, foo)

which gives you access to foo() without needing the fully qualified reference PACKAGE::foo().

But these aren't the only two options. You can also use the except argument to exclude just a handful of imports:

import(PACKAGE, except=c(foo,bar))

which gives you everything from PACKAGE's namespace but foo() and bar(). This is useful - as in your case - for avoiding conflicts.

For roxygen, great catch on figuring out that you can do:

#' @rawNamespace import(PACKAGE, except = foo)

to pass a raw NAMESPACE directive through roxygen.