A minimal, unifying API for scripts and packages to report progress
updates from anywhere including when using parallel processing. The
package is designed such that the developer can to focus on what
progress should be reported on without having to worry about how
to present it. The end user has full control of how, where, and
when to render these progress updates, e.g. in the terminal using
utils::txtProgressBar() or progress::progress_bar(), in a graphical
user interface using utils::winProgressBar(), tcltk::tkProgressBar()
or shiny::withProgress(), via the speakers using beep::beepr(), or
on a file system via the size of a file. Anyone can add additional,
customized, progression handlers. The 'progressr' package uses R's
condition framework for signaling progress updated. Because of this,
progress can be reported from almost anywhere in R, e.g. from
classical for and while loops, from map-reduce APIs like the lapply()
family of functions, 'purrr', 'plyr', and 'foreach'. It will also
work with parallel processing via the 'future' framework, e.g.
future.apply::future_lapply(), furrr::future_map(), and 'foreach'
with 'doFuture'. The package is compatible with Shiny applications.