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Build Status Build status CRAN\_Status\_Badge Downloads from the RStudio CRAN mirror Project Status: Active - The project has reached a stable, usable state and is being actively developed.

functools provides tools for Functional Programming in R. It accomplishes several goals:

  • Add support to the usual higher order functional suspects (Filter(), Map(), Reduce(), etc.) with higher order functions (Compose(), Memoise(), Partial(), Reject(), Fail_With(), Reduce_Right(), All(), Any(), and Best()).

  • Supply higher order function generators (Andify() and Orify()) to make composing predicate functions easier.

  • Provide wrappers (Apply(), Lapply(), Mapply(), Sapply(), Tapply(), and Vapply()) around their respective base R functionals to create an API with consistent naming convention, positional arguments, and argument names.

  • Implement common constants as functions (True(), False(), Identity(), Null(), and Na()) for point-free programming.

  • Extend abstract concepts of existiness and truthiness through functions (Existy() and Truthy()).

functools achieves these goals through three main types of function design patterns:

  • Closures (functions that take data and return functions)

  • Functionals (functions that take functions and return data)

  • Function Operators (functions that take functions and return functions)


You can install:

  • the latest released version from CRAN with

  • the latest development version from github with

    if (packageVersion("devtools") < 1.6) {

If you encounter a clear bug, please file a minimal reproducible example on github.


The original author of functools is Paul Hendricks.

Support via Gratipay