Collections

Collection of generic data structures in Go 📦

Free software: MIT License

Project Description

Small, useful, zero dependency implementations of generic collection data structures in Go:

Hash sets
Stacks
Queues

I wrote these primarily for use in some of my other projects but they are useful enough to be applicable in most scenarios (thanks to Go 1.18 and generics!).

Installation

go get github.com/FollowTheProcess/collections

Quickstart

Set

A set is an unordered collection of unique items offering fast lookup and membership checking.

// Initialise a new set with a concrete type
s := set.New[string]()

// Add items to the set
s.Add("hello")
s.Add("sets")
s.Add("in")
s.Add("go")

// All the methods you'd expect
s.Contains("hello") // true
s.Length() // 4

// Remove an item,
s.Remove("go")
s.Length() // 3

// Rich comparison with other sets
other := set.New[string]()
other.Add("hello")
other.Add("more")

// Union: combine both sets into one
set.Union(s, other) // ["hello", "in", "sets", "more", "go"]

// Intersection: all items present in both sets
set.Intersection(s, other) // ["hello"]

// Difference: items in s but not in other
set.Difference(s, other) // ["sets", "in", "go"]

Stack

A stack is a LIFO data structure useful in a variety of situations.

// Initialise a new stack with a concrete type
s := stack.New[string]()

// Push items onto the stack
s.Push("hello")
s.Push("stacks")
s.Push("in")
s.Push("go")

s.Length() // 4

// Pop items off the stack in LIFO order
item, _ := s.Pop()
fmt.Println(item) // "go"

item, _ = s.Pop()
fmt.Println(item) // "in"

item, _ = s.Pop()
fmt.Println(item) // "stacks"

item, _ = s.Pop()
fmt.Println(item) // "hello"

// Popping from an empty stack returns an error
_, err := s.Pop()
fmt.Println(err) // "pop from empty stack"

Queue

A queue is a FIFO data structure useful in a variety of situations.

// Initialise a new queue with a concrete type
q := queue.New[string]()

// Push items into the back of the queue
q.Push("hello")
q.Push("queues")
q.Push("in")
q.Push("go")

q.Length() // 4

// Pop items off the front of the queue
item, _ := q.Pop()
fmt.Println(item) // "hello"

item, _ = q.Pop()
fmt.Println(item) // "queues"

item, _ = q.Pop()
fmt.Println(item) // "in"

item, _ = q.Pop()
fmt.Println(item) // "go"

// Popping from an empty queue returns an error
_, err := q.Pop()
fmt.Println(err) // "pop from empty queue"