Using the map family of functions in purrr

R’s base functional programming tool kit is a little sparse. The purrr package was created in order to extend it and create a complete and consistent set of tools for working with functions and data structures. purrr provides a set of functions for functional programming, including the widely used map family of functions. The map functions allow you to iterate over a collection (such as a list or vector) and apply a function to each element, returning the results as a new list or vector.

The functions vary according to what they expect as input, what they iterate over, and what types and structures they return. Like the apply functions, they can simplify repetitive tasks, such as data manipulation or model fitting, by automatically handling the iteration process for you but by ensuring they always return the specified types and structures they help us to build more streamlined and effective code that is less prone to bugs.

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