The progressify() function rewrites (transpiles) calls to sequential and parallel map-reduce functions such as base::lapply(), purrr::map(), foreach::foreach(), and plyr::llply() to signal progress updates. By combining this function with R's native pipe operator, you have a straightforward way to report progress on iterative computations with minimal refactoring, e.g. lapply(x, fcn) |> progressify() and purrr::map(x, fcn) |> progressify()'. It is compatible with the parallel-processing map-reduce packages future.apply', furrr', crossmap', foreach', doFuture', and futurize'. It also supports domain-specific packages including boot', fwb', lme4', partykit', sandwich', and SimDesign', e.g. boot::boot(data, stat, R) |> progressify()'.