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README

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Abstruct

The a package includes simple Go utilities for collection operation. This package is inspired by the language integrated query (LINQ) in .NET Framework. There are no structs/interfaces equivalent to the Enumerable class or the IEnumerable interface, so deferred execution using the iterator pattern is not possible.

Currently implemented

• AggregateSelect
  • the original function
• AggregateSelectWithIndex
  • the original function
• All
• Any
• Chunk
• ChunkWithErr
• Contains
• Distinct
• DistinctBy
• DistinctByWithErr
• Filters
  • the original function
  • Filters() returns results corresponding to filters and the unfiltered result.
• FirstOrDefault
• GroupBy
• GroupByWithErr
• LastOrDefault
• MaxBy
• MaxByWithErr
• MinBy
• MinByWithErr
• OrderBy
• OrderByWithErr
• OrderByDescending
• OrderByDescendingWithErr
• Select
• SelectWithErr
• SelectMany
• Sort
  • support for multi-sorting with combinations of OrderBy, ThenBy, OrderByDescending, and ThenByDescending.
• Sum
• SumWithErr
• Switch
  • the original function
  • Switch() returns results corresponding to cases and the unfiltered result.
• ToMap
  • as an alternative to ToDictionary
• ToMapWithErr
• Where
• WhereSelect
  • the original function
  • WhereSelect() is convenient when using Where() and Select() at the same time.
• WhereSelectWithErr

Todo

• Doc
• Implement
  • Aggregate
  • AsEnumerable
  • Average
  • Cast
  • Concat
  • Count
  • DefaultIfEmpty
  • ElementAt
  • ElementAtOrDefault
  • Empty
  • Except
  • ExceptBy
  • First
  • GroupJoin
  • Intersect
  • IntersectBy
  • Join
  • Last
  • LongCount
  • Max
  • Min
  • OfType
  • Order
  • OrderDescending
  • Prepend
  • Range
  • Repeat
  • Reverse
  • SequenceEqual
  • Single
  • SingleOrDefault
  • Skip
  • SkipLast
  • SkipWhile
  • Sum
    • for only number slice
  • Take
  • TakeLast
  • TakeWhile
  • ThenBy
  • ThenByDescending
  • ToArray
  • ToHashSet
  • ToList
  • ToLookup
  • TryGetNonEnumeratedCount
  • Union
  • UnionBy
  • Zip
• Test
  • ToMap
  • WhereSelect

Tests

• How to measure code coverage
  • go test -cover ./...
• How to find not covered lines of code
  • go test -cover ./... -coverprofile=cover.out
  • go tool cover -html=cover.out -o cover.html
  • see cover.html

Documentation

Index

• Variables
• func AggregateSelect[T, S any](src []T, initialF func(T) S, f func(S, T) S) S
• func AggregateSelectWithIndex[T, S any](src []T, initialF func(T) S, f func(S, T, int) S) S
• func All[T any](src []T, a func(T) bool) bool
• func Any[T any](src []T, a func(T) bool) bool
• func Chunk[T any](src []T, size int) [][]T
• func ChunkWithErr[T any](src []T, size int) ([][]T, error)
• func Contains[T comparable](src []T, e T) bool
• func Distinct[T comparable](src []T) []T
• func DistinctBy[T any, K comparable](src []T, d func(T) K) []T
• func DistinctByWithErr[T any, K comparable](src []T, d func(T) K) ([]T, error)
• func Filters[T any](src []T, fs ...func(T) bool) ([][]T, []T)
• func FirstOrDefault[T any](src []T) T
• func GroupBy[K comparable, T any](src []T, k func(T) K) map[K][]T
• func GroupByWithErr[K comparable, T any](src []T, k func(T) K) (map[K][]T, error)
• func LastOrDefault[T any](src []T) T
• func MaxBy[T any, S cmp.Ordered](src []T, m func(T) S) T
• func MaxByWithErr[T any, S cmp.Ordered](src []T, m func(T) S) (T, error)
• func MinBy[T any, S cmp.Ordered](src []T, m func(T) S) T
• func MinByWithErr[T any, S cmp.Ordered](src []T, m func(T) S) (T, error)
• func OrderBy[T any, S cmp.Ordered](src []T, o func(T) S) []T
• func OrderByDescending[T any, S cmp.Ordered](src []T, o func(T) S) []T
• func OrderByDescendingWithErr[T any, S cmp.Ordered](src []T, o func(T) S) ([]T, error)
• func OrderByWithErr[T any, S cmp.Ordered](src []T, o func(T) S) ([]T, error)
• func Select[T, S any](src []T, s func(T) S) []S
• func SelectMany[T, S any](src []T, s func(T) []S) []S
• func SelectWithErr[T, S any](src []T, s func(T) S) ([]S, error)
• func Sort[T any](src []T, cmps ...func(t1 T, t2 T) bool) []T
• func Sum[T any, S number](src []T, s func(T) S) S
• func SumWithErr[T any, S number](src []T, s func(T) S) (S, error)
• func Switch[T any](src []T, fs ...func(T) bool) ([][]T, []T)
• func ToMap[K comparable, T any](src []T, k func(T) K) map[K]T
• func ToMapWithErr[K comparable, T any](src []T, k func(T) K) (map[K]T, error)
• func Where[T any](src []T, w func(T) bool) []T
• func WhereSelect[T, S any](src []T, w func(T) bool, s func(T) S) []S
• func WhereSelectWithErr[T, S any](src []T, w func(T) bool, s func(T) S) ([]S, error)

Variables

var ErrArg error = errors.New("argument error")

var ErrDuplicateKeyValue error = errors.New("duplicate key value error")

Functions

func AggregateSelect

func AggregateSelect[T, S any](src []T, initialF func(T) S, f func(S, T) S) S

func AggregateSelectWithIndex

func AggregateSelectWithIndex[T, S any](src []T, initialF func(T) S, f func(S, T, int) S) S

func All

func All[T any](src []T, a func(T) bool) bool

func Any

func Any[T any](src []T, a func(T) bool) bool

func Chunk

func Chunk[T any](src []T, size int) [][]T

func ChunkWithErr

func ChunkWithErr[T any](src []T, size int) ([][]T, error)

func Contains

func Contains[T comparable](src []T, e T) bool

func Distinct

func Distinct[T comparable](src []T) []T

func DistinctBy

func DistinctBy[T any, K comparable](src []T, d func(T) K) []T

func DistinctByWithErr

func DistinctByWithErr[T any, K comparable](src []T, d func(T) K) ([]T, error)

func Filters

func Filters[T any](src []T, fs ...func(T) bool) ([][]T, []T)

func FirstOrDefault

func FirstOrDefault[T any](src []T) T

func GroupBy

func GroupBy[K comparable, T any](src []T, k func(T) K) map[K][]T

func GroupByWithErr

func GroupByWithErr[K comparable, T any](src []T, k func(T) K) (map[K][]T, error)

func LastOrDefault

func LastOrDefault[T any](src []T) T

func MaxBy

func MaxBy[T any, S cmp.Ordered](src []T, m func(T) S) T

func MaxByWithErr

func MaxByWithErr[T any, S cmp.Ordered](src []T, m func(T) S) (T, error)

func MinBy

func MinBy[T any, S cmp.Ordered](src []T, m func(T) S) T

func MinByWithErr

func MinByWithErr[T any, S cmp.Ordered](src []T, m func(T) S) (T, error)

func OrderBy

func OrderBy[T any, S cmp.Ordered](src []T, o func(T) S) []T

func OrderByDescending

func OrderByDescending[T any, S cmp.Ordered](src []T, o func(T) S) []T

func OrderByDescendingWithErr

func OrderByDescendingWithErr[T any, S cmp.Ordered](src []T, o func(T) S) ([]T, error)

func OrderByWithErr

func OrderByWithErr[T any, S cmp.Ordered](src []T, o func(T) S) ([]T, error)

func Select

func Select[T, S any](src []T, s func(T) S) []S

func SelectMany

func SelectMany[T, S any](src []T, s func(T) []S) []S

func SelectWithErr

func SelectWithErr[T, S any](src []T, s func(T) S) ([]S, error)

func Sort

func Sort[T any](src []T, cmps ...func(t1 T, t2 T) bool) []T

func Sum

func Sum[T any, S number](src []T, s func(T) S) S

func SumWithErr

func SumWithErr[T any, S number](src []T, s func(T) S) (S, error)

func Switch

func Switch[T any](src []T, fs ...func(T) bool) ([][]T, []T)

Switch is a function

func ToMap

func ToMap[K comparable, T any](src []T, k func(T) K) map[K]T

func ToMapWithErr

func ToMapWithErr[K comparable, T any](src []T, k func(T) K) (map[K]T, error)

func Where

func Where[T any](src []T, w func(T) bool) []T

func WhereSelect

func WhereSelect[T, S any](src []T, w func(T) bool, s func(T) S) []S

func WhereSelectWithErr

func WhereSelectWithErr[T, S any](src []T, w func(T) bool, s func(T) S) ([]S, error)