LINQ for Go with type parameters

LINQ (Language-Integrated Query) is a component that adds data querying capabilities of Microsoft .Net languages. This package provides the implementation of the LINQ functions for Go with type parameters.

Quick Start

Install

go get github.com/makiuchi-d/linq/v2

Example

package main

import (
	"fmt"

	"github.com/makiuchi-d/linq/v2"
)

type Student struct {
	Name  string
	Class string
	Score int
}

func main() {
	students := []Student{
		// generated by https://testdata.userlocal.jp/
		{"熊木 緑", "1-A", 953},
		{"山本 千佳子", "1-C", 559},
		{"星 雅彦", "1-B", 136},
		{"齊藤 綾子", "1-A", 149},
		{"杉原 和己", "1-C", 737},
		{"山路 信之", "1-B", 425},
		{"佐々木 淑子", "1-C", 759},
		{"三宅 直人", "1-B", 594},
		{"緒方 俊", "1-B", 405},
		{"稲井 隆生", "1-A", 495},
	}

	e1 := linq.FromSlice(students)
	e2 := linq.Where(e1, func(s Student) (bool, error) { return s.Class == "1-B", nil })
	e3 := linq.OrderByDescending(e2, func(s Student) (int, error) { return s.Score, nil })

	linq.ForEach(e3, func(s Student) error {
		fmt.Printf("%d %s\n", s.Score, s.Name)
		return nil
	})
}

Output:

594 三宅 直人
425 山路 信之
405 緒方 俊
136 星 雅彦

Functions

italics are unique to this package.

Sorting Data

• OrderBy
• OrderByDescending
• OrderByFunc
• ThenBy
• ThenByDescending
• Reverse

Set Operations

• Distinct
• DistinctBy
• Except
• ExceptBy
• Intersect
• IntersectBy
• Union
• UnionBy

Filtering Data

• Where

Quantifier Operations

• All
• Any
• Contains
• ContainsFunc

Projection Operations

• Select
• SelectMany
• Zip

Partitioning Data

• Skip
• SkipLast
• SkipWhile
• Take
• TakeLast
• TakeWhile
• Chunk

Join Operations

• GroupJoin
• Join

Grouping Data

• GroupBy

Generation Operations

• DefaultIfEmpty
• Empty
• Range
• Repeat

Element Operations

• ElementAt
• ElementAtOrDefault
• First
• FirstOrDefault
• Last
• LastOrDefault
• Single
• SingleOrDefault

Converting Data Types

• FromMap
• FromSlice
• ToMap
• ToMapFunc
• ToSlice

Concatenation Operations

• Concat

Aggregation Operations

• Aggregate
• Average
• Count
• Max
• MaxBy
• MaxByFunc
• Min
• MinBy
• MinByFunc
• Sum
• Sumf

Other

• ForEach
• Generator

C# LINQ Documents

Standard Query Operators

Sorting Data

• [x] OrderBy
• [x] OrderByDescending
• [x] ThenBy
• [x] ThenByDescending
• [x] Reverse

Set Operations

• [x] Distinct
• [x] DistinctBy
• [x] Except
• [x] ExceptBy
• [x] Intersect
• [x] IntersectBy
• [x] Union
• [x] UnionBy

Filtering Data

• [ ] OfType
• [x] Where

Quantifier Operations

• [x] All
• [x] Any
• [x] Contains

Projection Operations

• [x] Select
• [x] SelectMany
• [x] Zip

Partitioning Data

• [x] Skip
• [x] SkipLast
• [x] SkipWhile
• [x] Take
• [x] TakeLast
• [x] TakeWhile
• [x] Chunk

Join Operations

• [x] Join
• [x] GroupJoin

Grouping Data

• [x] GroupBy
• [ ] ToLookup

Generation Operations

• [x] DefaultIfEmpty
• [x] Empty
• [x] Range
• [x] Repeat

Equality Operations

• [ ] SequenceEqual

Element Operations

• [x] ElementAt
• [x] ElementAtOrDefault
• [x] First
• [x] FirstOrDefault
• [x] Last
• [x] LastOrDefault
• [x] Single
• [x] SingleOrDefault

Converting Data Types

• [ ] AsEnumerable
• [ ] AsQueryable
• [ ] Cast
• [ ] OfType
• [ ] ToArray
• [ ] ToDictionary
• [ ] ToList
• [ ] ToLookup

Concatenation Operations

• [x] Concat

Aggregation Operations

• [x] Aggregate
• [x] Average
• [x] Count
• [ ] LongCount
• [x] Max
• [x] MaxBy
• [x] Min
• [x] MinBy
• [x] Sum