automagic (version 0.5.1)

parse_packages: Parse R code for required packages

Description

Parses an R or R Markdown file for the package names that would be required to run the code.

Usage

parse_packages(fl)

Arguments

fl

file to parse for required package names

Value

a vector of package names as character strings

Details

This function uses regular expressions to search through a file containing R code to find required package names. It extracts not only package names denoted by library and require, but also packages not attached to the global namespace, but are still called with :: or :::.

Because it relies on regular expressions, it assumes all packages adhere to the valid CRAN package name rules (contain only ASCII letters, numbers, and dot; have at least two characters and start with a letter and not end it a dot). Code is also tidying internally, making the code more predictable and easier to parse (removes comments, adds whitespace around operators, etc). R Markdown files are also supported by extracting only R code using purl.

See Also

install_package_guess, automagic

Examples

# NOT RUN {
cat('library(ggplot2)\n # library(curl)\n require(leaflet)\n CB::date_print()\n',file='temp.R')
parse_packages('temp.R')
unlink('temp.R')
# }