Skip to contents

Build a lookup table of CRAN archive first appearance dates

Source: R/get_first_release.R
build_archive_df.Rd

Constructs a data frame mapping package names to their earliest known appearance in the CRAN archive, inferred from file modification times.

Usage

build_archive_df(cran_archive_db = NULL)

Arguments

cran_archive_db

Optional result of tools::CRAN_archive_db(). If not supplied, it is retrieved internally.

Value

A data frame with columns:

  • package – package name

  • archive_date – earliest archive date (Date) or NA

Details

The CRAN archive database is a named list of data frames, one per package. For each package, the earliest file mtime is used as a proxy for the archive entry date. Packages with empty archive entries return NA.

This function is intended to be called once and the result reused for efficient per-package lookups.

Examples

if (FALSE) { # \dontrun{
archive_db <- tools::CRAN_archive_db()
archive_df <- build_archive_df(archive_db)
} # }