twharmon / slices

Pure functions for slices.

Slices

Pure functions for slices. Slices are never operated on "in place". Instead, new ones are returned.

Documentation

For full documentation see pkg.go.dev.

Install

go get github.com/twharmon/slices

Usage

package main

import (
	"fmt"

	"github.com/twharmon/slices"
)

func main() {
	// use plain go slices
	s := []string{"foo", "ba"}

	// append new item to end of slice
	s = slices.Append(s, "b")
	fmt.Println(s) // [foo ba b]
	
	// sort by string length, ascending
	sorted := slices.SortFunc(s, func(a, b string) bool {
		return len(a) < len(b)
	})
	// original slice is not chaged
	fmt.Println(s, sorted) // [foo ba b] [b ba foo]

	// sum the lengths of all the strings    
	totalLen := slices.Reduce(s, func(cnt int, i string) int {
		return cnt + len(i)
	})
	fmt.Println(totalLen) // 6

	// find the first item with length 2
	str := slices.Find(s, func(item string) bool { return len(item) == 2 })    
	fmt.Println(str) // ba

	// map slice to new slice of different type
	ints := slices.Map(s, func(item string) int { return len(s) })    
	fmt.Println(ints) // [3 2 1]
}

Benchmarks

goos: darwin
goarch: arm64
pkg: github.com/twharmon/slices

BenchmarkSortFunc/std_lib-10         	  116497	      9424 ns/op	    4152 B/op	       3 allocs/op
BenchmarkSortFunc/slices-10          	  101791	     11479 ns/op	    4096 B/op	       1 allocs/op
BenchmarkSort/std_lib-10             	  125790	      9441 ns/op	    4120 B/op	       2 allocs/op
BenchmarkSort/slices-10              	  113931	     10162 ns/op	    4096 B/op	       1 allocs/op

BenchmarkReverse-10                  	 1631348	       749.4 ns/op	    4096 B/op	       1 allocs/op
BenchmarkConcat-10                   	  275463	      4259 ns/op	   40960 B/op	       1 allocs/op
BenchmarkFilter-10                   	 1000000	      1018 ns/op	    4096 B/op	       1 allocs/op

BenchmarkUnion/2x20-10               	 3258876	       361.2 ns/op	      32 B/op	       1 allocs/op
BenchmarkUnion/20x2-10               	  502176	      2329 ns/op	    1592 B/op	       3 allocs/op
BenchmarkUnion/20x2000-10            	    1140	   1054108 ns/op	    1590 B/op	       3 allocs/op
BenchmarkUnion/2000x20-10            	     714	   1697117 ns/op	  142481 B/op	      39 allocs/op

BenchmarkIntersection/2x20-10        	 2380771	       498.0 ns/op	      48 B/op	       1 allocs/op
BenchmarkIntersection/20x2-10        	  821226	      1427 ns/op	    1196 B/op	       3 allocs/op
BenchmarkIntersection/20x2000-10     	    1178	   1020620 ns/op	    1282 B/op	       3 allocs/op
BenchmarkIntersection/2000x20-10     	     938	   1276258 ns/op	  203294 B/op	      58 allocs/op

Contribute

Make a pull request.