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Find the first CRAN release exporting a symbol

Source: R/get_first_export_cran.R
get_first_export_cran.Rd

This function identifies the earliest version of a package on CRAN that explicitly exports a given symbol in its NAMESPACE via export(). It intentionally ignores exportPattern() to avoid false positives.

Usage

get_first_export_cran(
  package,
  fname,
  date_only = FALSE,
  repos = "https://cloud.r-project.org",
  cache_dir = getOption("ggext.cran_cache", file.path(tempdir(), "cran_export_cache"))
)

Arguments

package

Character. The name of the CRAN package (e.g. "ggplot2").

fname

Character. The symbol to search for (e.g. "geom_point").

date_only

Logical. If TRUE, return only the publication Date. Defaults to FALSE.

repos

Character. The CRAN mirror URL. Defaults to "https://cloud.r-project.org".

cache_dir

Character. Directory used to cache parsed CRAN metadata. Defaults to getOption("ggext.cran_cache"), falling back to a temporary directory.

Value

If date_only = TRUE, a Date object or NA.

Otherwise, a one-row data.frame with columns:

  • package: package name

  • fname: function name

  • version: CRAN version where the symbol is first exported

  • first_cran: CRAN publication date (may be NA for older releases)

  • is_reexport: logical indicating whether the symbol is imported via importFrom() (i.e., a re-export)

Returns NULL if the symbol is never exported.

Details

Re-exports are detected by checking for a corresponding importFrom() directive for the same symbol.

Results are cached per package and per version to avoid repeatedly downloading and parsing CRAN tarballs.