fast-replace/go-fast-replace/internal/corpus/corpus.go

package corpus

import (
	"fmt"
	"math/rand"
	"strings"
)

func MakeCorpus(n int) string {
	// Generate data
	lineLength := 100
	var lines []string
	for i := 1; i <= n; i++ {
		lines = append(lines, makeLine(i, lineLength))
	}

	// Randomize
	for i := range lines {
	    j := rand.Intn(i + 1)
	    lines[i], lines[j] = lines[j], lines[i]
	}

	return strings.Join(lines, "\n")
}

func makeLine(line int, lineLength int) string {
	var key string = fmt.Sprintf("%06d", line)
	lineLength = lineLength - len(key)

	var firstLen int = rand.Intn(lineLength)
	var secondLen int = lineLength - firstLen

	return randomString(firstLen) + key + randomString(secondLen)
}

func randomString(n int) string {
    var letters = []rune("abcdefghijklmnopqrstuvwxyz")
	var length int = len(letters)

    s := make([]rune, n)
    for i := range s {
        s[i] = letters[rand.Intn(length)]
    }

    return string(s)
}