testing string reversals

reversal_test.go

package tests

// RESULTS
// 
// Benchmark_Reveral_Buffer-4       3000000               507 ns/op
// Benchmark_Reveral_Concat-4        500000              3703 ns/op
// Benchmark_Reversal_Append-4       300000              4496 ns/op

import (
	"testing"
	"bytes"
)

var subject = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
var reversed = "ZYXWVUTSRQPONMLKJIHGFEDCBAzyxwvutsrqponmlkjihgfedcba9876543210"

func Reversal_Buffer(s string) string {
		var ret bytes.Buffer
		
		for i := len(s); i > 0; i-- {
			ret.WriteByte(s[i-1])
		}

		return ret.String()
}

func Reversal_Concat(s string) string {
		var ret string

		for i := 0; i < len(s); i++ {
			ret = s[i:i+1] + ret
		}

		return ret
}

func Reversal_Append(s string) string {
		var ret []byte

		for i := 0; i < len(s); i++ {
			ret = append([]byte{s[i]}, ret...)
		}

		return string(ret)
}

func Test_Reversal_Buffer(t *testing.T) {
	if Reversal_Buffer(subject) != reversed {
		t.Error("bad reversal")
	}
}

func Test_Reversal_Concat(t *testing.T) {
	if Reversal_Concat(subject) != reversed {
		t.Error("bad reversal")
	}
}

func Test_Reversal_Append(t *testing.T) {
	if Reversal_Append(subject) != reversed {
		t.Error("bad reversal")
	}
}

func Benchmark_Reveral_Buffer(b *testing.B) {
	for n := 0; n < b.N; n++ {
		Reversal_Buffer(subject)
	}
}

func Benchmark_Reveral_Concat(b *testing.B) {
	for n := 0; n < b.N; n++ {
		Reversal_Concat(subject)
	}
}

func Benchmark_Reversal_Append(b *testing.B) {
	for n := 0; n < b.N; n++ {
		Reversal_Append(subject)
	}
}