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rexpss

How can I use something like `package::%to%` in a function/package

I want to use functions from the expss package in my own functions/packages. I usually call the functions along with their packages (e.g. dplyr::mutate(...)).

The expss package has a function/operator %to%, and I don't know how I can do the same here, i.e. expss::%to% doesn't work, neither does expss::'%to%'.

What can I do?

Solution

  • Infix operators must be attached to be usable; you can’t use them prefixed with the package name.1

    Inside a package, the conventional way is to add an importFrom directive to your NAMESPACE file or, if you’re using ‘roxygen2’, add the following Roxygen directive somewhere:

    #' @importFrom expss %to%

    Outside of package code, you could use ‘box’ to attach just the operator:

    box::use(expss[`%to%`])

    Or you can use simple assignment (this is the easiest solution in the simplest case but it becomes a lot of distracting code for multiple operators):

    `%to%` = expss::`%to%`

    1 Except using regular function call syntax:

    expss::`%to%`(…)