roxytypes

Typed parameter definition roxygen2 tag

Quick Start

Convert your package

If you already have a codebase and you’d like to convert it to use roxytypes, you can use:

roxytypes::convert()

You’ll be prompted with a preview of changes and the option to continue by making edits or aborting changes. By default, will look for type signatures as parenthesized inline code at the start of your descriptions. That is, that descriptions are written like (`type`) description.

If that’s not the case, you can specify your own format. For example, if your types were in square brackets, you could specify a format like:

roxytypes::convert(format = "[`{type}`] {description}")

By default, conversions will only happen if an existing type is found using the provided type format. If you’d like to convert all possible tags, pass unmatched = TRUE. However new typed tags will only be partially populated and will produce documentation notes until they are filled in.

Tags from scratch

Use the @typed tag to define parameters, replacing the @param tag.

The @typed tag expects input in the form:

#' @typed <var>: <type>
#'   <description>

The newline after the type field is a meaningful delimiter to avoid having to disambiguate between type annotations and written descriptions. In practice it looks something like this:

#' Example
#'
#' @typed who: character
#'   Who you'd like to say hello to.
#'
#' @typedreturn: NULL
#'   `cat` output returned.
#'
hello <- function(who = "World") {
  cat("Hello, ", who, "!\n", sep = "")
}

Next order of business is to install the package and declare the roxygen2 dependency.

DESCRIPTION

Config/Needs/documentation:
    roxytypes
Roxygen:
    list(markdown = TRUE, packages = "roxytypes")

With all of that set up, the only thing left is to rebuild your docs!

Configuration

roxytypes accepts a number of configuration fields. For defaults, see ?config.

Formatting

The style of documentation can be configured using Config/roxytypes:

DESCRIPTION

Config/roxytypes: list(format = "(`{type}`): {description}")

The format string uses glue and can be expected to have fields name, type and description. The parameter name will always be the named argument value, but may be reused for parts of the description.

Altenatively, you can provide a function that accepts the parsed roxygen2 tag and the fields as named arguments.

For more advanced formatting, see ?tags or ?typed.

roxylint compatible

@typed tags come with their own roxylint linters. To benefit from linting of @typed tags, simply add the roxylint::roxylint roclet.

DESCRIPTION

Roxygen:
  list(
    markdown = TRUE,
    packages = c("roxylint", "roxytypes"),
    roclets = c("namespace", "rd", "roxylint::roxylint")
  )

tip!

If your Roxygen section gets too long, you can also put this content in man/roxygen/meta.R where you can benefit from all the perks of your editor’s R file handling.