Check for presence of a package — checkPkgs • rock

This function efficiently checks for the presence of a package without loading it (unlike library() or require(). This is useful to force yourself to use the package::function syntax for addressing functions; you can make sure required packages are installed, but their namespace won't attach to the search path.

checkPkgs(
  ...,
  install = FALSE,
  load = FALSE,
  repos = "https://cran.rstudio.com"
)

Arguments

...: A series of packages. If the packages are named, the names are the package names, and the values are the minimum required package versions (see the second example).
install: Whether to install missing packages from repos.
load: Whether to load packages (which is exactly not the point of this function, but hey, YMMV).
repos: The repository to use if installing packages; default is the RStudio repository.

Value

Invisibly, a vector of the available packages.

Examples

# \donttest{
rock::checkPkgs('base');

### Require a version
rock::checkPkgs(rock = "0.5.0");

### This will show the error message
tryCatch(
  rock::checkPkgs(
    base = "99",
    stats = "42.5",
    ufs = 20
  ),
  error = print
);
#> <simpleError in rock::checkPkgs(base = "99", stats = "42.5", ufs = 20): Of package(s) 'base', 'stats' & 'ufs', you need at least versions 99, 42.5 & 20, respectively. Install those with:
#> 
#> install.packages(c('base', 'stats' & 'ufs'));
#> >
# }