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Find the package qualifier for a topic

Source: R/topic.R
topic_qualifier.Rd

Determines whether a topic needs a package qualifier when linking from the documentation of another package. The from package is checked first, followed by packages, and then the base packages. Re-exported objects are attributed to their original package. Results are cached alongside the from package's topic index, so repeated lookups are cheap.

Usage

topic_qualifier(topic, from, packages = character())

Arguments

topic

A single string naming an alias, matched exactly.

from

The name or source directory of the package you are linking from. If it documents topic, no qualifier is needed.

packages

A character vector of additional packages to search, typically the dependencies of from (as computed by pkg_search_deps()). Base packages are always included.

Value

  • NULL if the topic isn't documented by from, packages, or the base packages.

  • NA_character_ if the topic needs no qualifier because it's documented by from or a base package.

  • Otherwise, the package name(s) that could qualify the topic: usually one, but more if the topic is ambiguous, in which case it's up to the caller to decide how to respond.

Examples

topic_qualifier("rnorm", "stats")
#> [1] NA