go-intersect

Find the intersection of two iterable values.

This library provides multiple implementations which each have their strong and weak points.

Read the docs.

Installation

$ go get github.com/juliangruber/go-intersect

Example

import "github.com/juliangruber/go-intersect"
import "fmt"

func main() {
  a := []int{1, 2, 3}
  b := []int{2, 3, 4}
  fmt.Println(intersect.SimpleGeneric(a, b))
}

Generics

Go v1.18 now supports generics which increases performance compared to reflection. Below are benchmark results between reflection and generics of the hash intersection functions. Slice sizes of 1, 10, 100 1.000 and 10.000 are used.

The average time and allocated bytes are more than halved when using generics, and the number of times bytes have to be allocated from the heap are improved significantly.

Name	Runs	Average	Allocated	Allocations from heap
BenchmarkHash/Size_1-_interface-8	4.631.326	248.1 ns/op	80 B/op	5 allocs/op
BenchmarkHash/Size_1-_generics-8	22.551.091	46.19 ns/op	8 B/op	1 allocs/op
BenchmarkHash/Size_10-_interface-8	581.262	2.042 ns/op	547 B/op	24 allocs/op
BenchmarkHash/Size_10-_generics-8	2.043.096	549.6 ns/op	187 B/op	2 allocs/op
BenchmarkHash/Size_100-_interface-8	59.907	18.721 ns/op	7.325 B/op	213 allocs/op
BenchmarkHash/Size_100-_generics-8	126.622	8.221 ns/op	3.359 B/op	19 allocs/op
BenchmarkHash/Size_1000-_interface-8	7.114	22.1721 ns/op	112.405 B/op	2.038 allocs/op
BenchmarkHash/Size_1000-_generics-8	13.345	91.197 ns/op	53.323 B/op	74 allocs/op
BenchmarkHash/Size_10000-_interface-8	523	2.067.330 ns/op	875.731 B/op	20.173 allocs/op
BenchmarkHash/Size_10000-_generics-8	1.264	828.214 ns/op	427.541 B/op	320 allocs/op