Book Image

Learning Functional Programming in Go

By : Lex Sheehan
Book Image

Learning Functional Programming in Go

By: Lex Sheehan

Overview of this book

Lex Sheehan begins slowly, using easy-to-understand illustrations and working Go code to teach core functional programming (FP) principles such as referential transparency, laziness, recursion, currying, and chaining continuations. This book is a tutorial for programmers looking to learn FP and apply it to write better code. Lex guides readers from basic techniques to advanced topics in a logical, concise, and clear progression. The book is divided into four modules. The first module explains the functional style of programming: pure functional programming, manipulating collections, and using higher-order functions. In the second module, you will learn design patterns that you can use to build FP-style applications. In the next module, you will learn FP techniques that you can use to improve your API signatures, increase performance, and build better cloud-native applications. The last module covers Category Theory, Functors, Monoids, Monads, Type classes and Generics. By the end of the book, you will be adept at building applications the FP way.
Table of Contents (21 chapters)
Title Page
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Itertools


Itertools is a Go package that provides many of the same high-order functions from the Python standard library.

Next, we see the different types of high-order functions provided by Itertools. High-order functions provide the vocabulary for the declarative coding style.

Infinite iterator creators:

  • Count(i): Infinite count from i
  • Cycle(iter): Infinite cycling of iter (requires memory)
  • Repeat(element [, n]): Repeat the element n times (or infinitely)

Iterator destroyers:

  • Reduce(iter, reducer, memo): Reduce (or Foldl) across the iterator
  • List(iter): Create a list from the iterator

Iterator modifiers:

  • Chain(iters...): Chain together multiple iterators.
  • DropWhile(predicate, iter): Drop elements until predicate(el) == false.
  • TakeWhile(predicate, iter): Take elements until predicate(el) == false.
  • Filter(predicate, iter): Filter out elements when predicate(el) == false.
  • FilterFalse(predicate, iter): Filter out elements when predicate(el) == true.
  • Slice(iter, start[, stop[, step]]): Drop elements until...