README.md

Comparison betewen the "map as a set" and a string slice accessed by two functions. "Sort" based and "for" based search included too.

Use this command to run the benchmark tests

go test -bench=.

main.go

package main

import (
	"sort"
)

func main() {}

func containsWithSort(s []string, searchterm string) bool {
	i := sort.SearchStrings(s, searchterm)
	return i < len(s) && s[i] == searchterm
}

func containsWithFor(s []string, e string) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

main_test.go

package main

import (
	"testing"
)

var stringSlice = []string{"hello", "world", "good", "bad", "red", "back"}

var mapWithEmptyStruct = map[string]struct{}{
	"hello": {},
	"world": {},
	"good":  {},
	"bad":   {},
	"red":   {},
	"back":  {},
}

const (
	notElement = "notInTheListOrMap"
	element    = "good"
)

func BenchmarkContainsWithSortNotFound(b *testing.B) {
	for i := 0; i < b.N; i++ {
		containsWithSort(stringSlice, notElement)
	}
}

func BenchmarkContainsWithSortFound(b *testing.B) {

	for i := 0; i < b.N; i++ {
		containsWithSort(stringSlice, element)
	}
}

func BenchmarkContainsWithForNotFound(b *testing.B) {
	for i := 0; i < b.N; i++ {
		containsWithFor(stringSlice, notElement)
	}
}

func BenchmarkContainsWithForFound(b *testing.B) {
	for i := 0; i < b.N; i++ {
		containsWithFor(stringSlice, element)
	}
}

func BenchmarkContainsMapNotFound(b *testing.B) {
	for i := 0; i < b.N; i++ {
		_, _ = mapWithEmptyStruct[notElement]
	}
}

func BenchmarkContainsMapFound(b *testing.B) {
	for i := 0; i < b.N; i++ {
		_, _ = mapWithEmptyStruct[element]
	}
}

For anyone viewing these and interested at a glance, these were my benchmark results. Obviously, these will vary with hardware and current load so run them yourself for a better idea.

CPU: AMD Ryzen 7 3700X

Run 1

Running tool: C:\Go\bin\go.exe test -benchmem -run=^$ gist.github.com/NorbertFenk/7bed6760198800207e84f141c41d93c7 -bench ^(BenchmarkContainsWithSortNotFound|BenchmarkContainsWithSortFound|BenchmarkContainsWithForNotFound|BenchmarkContainsWithForFound|BenchmarkContainsMapNotFound|BenchmarkContainsMapFound)$

goos: windows
goarch: amd64
pkg: gist.github.com/NorbertFenk/7bed6760198800207e84f141c41d93c7
BenchmarkContainsWithSortNotFound-16    	59999400	        19.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsWithSortFound-16       	63158226	        19.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsWithForNotFound-16     	275229483	         4.28 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsWithForFound-16        	274600044	         4.36 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsMapNotFound-16         	158269209	         7.58 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsMapFound-16            	227704286	         5.30 ns/op	       0 B/op	       0 allocs/op
PASS
ok  	gist.github.com/NorbertFenk/7bed6760198800207e84f141c41d93c7	9.541s
Success: Benchmarks passed.

Run 2

goos: windows
goarch: amd64
pkg: gist.github.com/NorbertFenk/7bed6760198800207e84f141c41d93c7
BenchmarkContainsWithSortNotFound-16    	63147924	        19.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsWithSortFound-16       	60002400	        19.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsWithForNotFound-16     	279070026	         4.27 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsWithForFound-16        	275229609	         4.36 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsMapNotFound-16         	158520411	         7.59 ns/op	       0 B/op	       0 allocs/op
BenchmarkContainsMapFound-16            	226684977	         5.27 ns/op	       0 B/op	       0 allocs/op
PASS
ok  	gist.github.com/NorbertFenk/7bed6760198800207e84f141c41d93c7	9.556s
Success: Benchmarks passed.