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

Proof theory


Proof theory is a branch of mathematics where we make assumptions and apply logic to prove something. For example, if a and b can be proven to be true, then a is true and so is b.

Logical connectives

The following table depicts logical connectives, in order of precedence:

Symbol

Math name

English name

Go operator

Example

Meaning

¬  

Negation

NOT

!

¬a

not a

Conjunction

AND

&&

a ∧ b

a and b

Exclusive disjunction

exclusive or (XOR)

NA

a ⊕ b

either a or b (but not both)

Disjunction

OR

||

a ∨ b

a or b

Universal quantification

∀ x: A(x) means A(x) is true for all x

NA

∀a:A

all values a of type A

Existential quantification

∃ x: A(x) means there is at least one x such that A(x) is true

NA

∃a:A

there exists some value a of type A

Material implication

Implies

NA

a ⇒ b

if a then b

Material equivalence

a ⇔ b is true only if both a and b are false, or both a and b are true

NA

a ⇔ b

a if and only if b

Is defined as

a ≡ b means a is defined to be another name for b

NA

a ≡ b

a is logically equivalent to b

Turnstile

a ⊢ b means a...