functools

functools extends 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(), 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(), Na()) for point-free programming.

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

Installation

You can install:

• the latest released version from CRAN with

  install.packages("functools")

• the latest development version from github with

  if (packageVersion("devtools") < 1.6) {
    install.packages("devtools")
  }
  devtools::install_github("paulhendricks/functools")

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