collections

README

go-collections

Basic collections with Go using generics.

Table of Contents

• Installation
• Usage
• Contributing
• License

Installation

go get github.com/gopher-utils/go-collections

Usage

Below is an example of how you can use go-collections in your project.

package main

import (
	"fmt"

	"github.com/gopher-utils/go-collections/collections"
)

func main() {
	// Create a new empty list of integers with capacity 10
	emptyList := collections.NewList[int](10)
	// Insert a number
	emptyList.Add(1)
	fmt.Println(emptyList) // Prints [1]

	// Create a list of integers with repeating ones of size 5
	repeatingList := collections.RepeatingList(1, 5)
	fmt.Println(repeatingList) // Prints [1,1,1,1,1]

	// Create a list from array
	fromArrayList := collections.ToList([]int{2, 3, 4})
	fmt.Println(fromArrayList) // Prints [2,3,4]

	// Concatenate two lists together
	emptyList.Extend(fromArrayList)
	fmt.Println(emptyList) // Prints [1,2,3,4]
}

Please check the documentation for more comprehensive usage.

Contributing

Any contributions to this repo are always welcome. Please check the Contribution Guidelines for details.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Documentation

Index

• Variables
• func Avg[V Number](c Collection[V]) V
• func Max[V Number](c Collection[V]) V
• func Min[V Number](c Collection[V]) V
• func Reduce[T CollectionElement](l *List[T], callback listReduceFunction[T], initialValue T) T
• func Sum[V Number](c Collection[V]) V
• type Collection
• type CollectionElement
• type CollectionType
• type Equatable
• type GenericType
• type List
  • func Map[T CollectionElement, E CollectionElement](l *List[T], callback listMapFunction[T, E]) *List[E]
  • func NewList[T CollectionElement](capacity int) *List[T]
  • func RepeatingList[T CollectionElement](element T, times int) *List[T]
  • func ToList[T CollectionElement](array []T) *List[T]
  • func (l *List[T]) Add(item T)
  • func (l *List[T]) Contains(item T) bool
  • func (l *List[T]) CountOf(item T) (count int)
  • func (l *List[T]) Distinct() *List[T]
  • func (l *List[T]) Extend(l2 *List[T])
  • func (l *List[T]) Get(index int) (item T, err error)
  • func (l *List[T]) IndexOf(item T) int
  • func (l *List[T]) RemoveAll(item T) error
  • func (l *List[T]) RemoveDuplicates()
  • func (l *List[T]) RemoveFirst(item T) error
  • func (l *List[T]) Size() int
  • func (l *List[T]) String() string
  • func (l *List[T]) ToArray() []T
  • func (_ List[T]) Type() CollectionType
  • func (l *List[T]) Where(f func(T) bool) *List[T]
• type Number
• type Set
  • func NewSet[T CollectionElement]() *Set[T]
  • func ToSet[T CollectionElement](array []T) *Set[T]
  • func (s *Set[T]) Add(item T)
  • func (s *Set[T]) Clear()
  • func (s *Set[T]) Contains(item T) bool
  • func (s *Set[T]) Difference(s2 *Set[T]) *Set[T]
  • func (s *Set[T]) Extend(s2 *Set[T])
  • func (s *Set[T]) Intersection(s2 *Set[T]) *Set[T]
  • func (s *Set[T]) Remove(item T) error
  • func (s *Set[T]) Size() int
  • func (s *Set[T]) String() string
  • func (s *Set[T]) ToArray() []T
  • func (_ Set[T]) Type() CollectionType
  • func (s *Set[T]) Union(s2 *Set[T]) *Set[T]

Variables

var (
	ErrIndexOutOfRange = errors.New("linq: index out of range")
	ErrItemNotFound    = errors.New("linq: item not found")
)

Functions

func Avg

func Avg[V Number](c Collection[V]) V

Returns the average of all elements present in the given collection. This method supports only numerical types.

func Max

func Max[V Number](c Collection[V]) V

Returns maximum element present in the given collection. This method supports only numerical types.

func Min

func Min[V Number](c Collection[V]) V

Returns minimum element present in the given collection. This method supports only numerical types.

func Reduce

func Reduce[T CollectionElement](l *List[T], callback listReduceFunction[T], initialValue T) T

Use Reduce to reduce the given list elements to a single element of same type T based on a callback function.

func Sum

func Sum[V Number](c Collection[V]) V

Returns the sum of all elements present in the given collection. This method supports only numerical types.

Types

type Collection

type Collection[T CollectionElement] interface {
	// Returns the type of the given collection.
	Type() CollectionType
	// Returns the size of the given collection.
	Size() int
	// Returns the description of the given collection.
	String() string
}

Generic interface that all collections must implement.

type CollectionElement

type CollectionElement interface {
	Equatable
}

A Generic interface that must be implemented by collection elements. By default, all primitive types and structs containing primitive types implement this interface.

type CollectionType

type CollectionType int

Typed constant that helps in determining the collection type.

const (
	TypeList    CollectionType = 0
	TypeSet     CollectionType = 1
	TypeHashmap CollectionType = 2
)

type Equatable

type Equatable interface {
	comparable
}

Interface with comparable constraint (== & != operator supportable).

type GenericType

type GenericType interface {
	Number | string
}

type List

type List[T CollectionElement] struct {
	// contains filtered or unexported fields
}

Collection that stores homogenous elements in a fixed order.

func Map

func Map[T CollectionElement, E CollectionElement](l *List[T], callback listMapFunction[T, E]) *List[E]

Use Map method to transform a list of a given type to another type.

func NewList

func NewList[T CollectionElement](capacity int) *List[T]

Factory method to create an empty list with predefined capacity.

func RepeatingList

func RepeatingList[T CollectionElement](element T, times int) *List[T]

Factory method to create a list with repeating values

func ToList

func ToList[T CollectionElement](array []T) *List[T]

Factory method to create a list from an array.

func (*List[T]) Add

func (l *List[T]) Add(item T)

Add element to list.

func (*List[T]) Contains

func (l *List[T]) Contains(item T) bool

Checks whether an element is present in the list.

func (*List[T]) CountOf

func (l *List[T]) CountOf(item T) (count int)

Returns number of occurences of given element in the list.

func (*List[T]) Distinct

func (l *List[T]) Distinct() *List[T]

Returns a new list containing unique elements.

func (*List[T]) Extend

func (l *List[T]) Extend(l2 *List[T])

Concatenate a list with another list.

func (*List[T]) Get

func (l *List[T]) Get(index int) (item T, err error)

Returns list element for a valid index. Returns error for an invalid index.

func (*List[T]) IndexOf

func (l *List[T]) IndexOf(item T) int

Returns the index of the first occurence of the element. If the element is not present in the list, it returns -1.

func (*List[T]) RemoveAll

func (l *List[T]) RemoveAll(item T) error

Removes all occurences of the given element from the list. Returns an error if the element is not present in the list.

func (*List[T]) RemoveDuplicates

func (l *List[T]) RemoveDuplicates()

Removes duplicates of elements in the list.

func (*List[T]) RemoveFirst

func (l *List[T]) RemoveFirst(item T) error

Removes first occurence of the given element from the list. Returns an error if the element is not present in the list.

func (*List[T]) Size

func (l *List[T]) Size() int

Returns the number of elements in the list.

func (*List[T]) String

func (l *List[T]) String() string

Returns a string description of the list.

func (*List[T]) ToArray

func (l *List[T]) ToArray() []T

Returns an slice containing elements of the list.

func (List[T]) Type

func (_ List[T]) Type() CollectionType

func (*List[T]) Where

func (l *List[T]) Where(f func(T) bool) *List[T]

Returns a filtered list based on the provided boolean function f.

type Number

type Number interface {
	int64 | float64 | int32 | int16 | int8 | int | float32
}

A Generic number interface that supports all basic number types.

type Set

type Set[T CollectionElement] struct {
	// contains filtered or unexported fields
}

Collection that stores a set of homogenous elements.

func NewSet

func NewSet[T CollectionElement]() *Set[T]

Factory method to create an empty set with predefined capacity.

func ToSet

func ToSet[T CollectionElement](array []T) *Set[T]

Factory method to create a set from an array.

func (*Set[T]) Add

func (s *Set[T]) Add(item T)

Add element to set.

func (*Set[T]) Clear

func (s *Set[T]) Clear()

Removes all elements from the set.

func (*Set[T]) Contains

func (s *Set[T]) Contains(item T) bool

Checks whether an element is present in the set.

func (*Set[T]) Difference

func (s *Set[T]) Difference(s2 *Set[T]) *Set[T]

Returns a new set instance containing elements that exists in the first set, but not in the second.

func (*Set[T]) Extend

func (s *Set[T]) Extend(s2 *Set[T])

Updates the current set to be it's union with another set.

func (*Set[T]) Intersection

func (s *Set[T]) Intersection(s2 *Set[T]) *Set[T]

Returns a new set instance containing the elements that exists in both sets.

func (*Set[T]) Remove

func (s *Set[T]) Remove(item T) error

Removes occurence of the given element from the set. Returns an error if the element is not present in the set.

func (*Set[T]) Size

func (s *Set[T]) Size() int

Returns the number of elements in the set.

func (*Set[T]) String

func (s *Set[T]) String() string

Returns a string description of the set.

func (*Set[T]) ToArray

func (s *Set[T]) ToArray() []T

Returns an slice containing elements of the set.

func (Set[T]) Type

func (_ Set[T]) Type() CollectionType

func (*Set[T]) Union

func (s *Set[T]) Union(s2 *Set[T]) *Set[T]

Returns a new set instance as the Union of both sets. This is the same as Extend, but without updating the rhs set.