package match

// todo common table of rune's length

import (

	"fmt"

	"strings"

)

const lenOne = 1

const lenZero = 0

const lenNo = -1

type Matcher interface {

	Match(string) bool

	Index(string) (int, []int)

	Len() int

	String() string

}

type Matchers []Matcher

func (m Matchers) String() string {

	var s []string

	for _, matcher := range m {

		s = append(s, fmt.Sprint(matcher))

	}

	return fmt.Sprintf("%s", strings.Join(s, ","))

}

// appendMerge merges and sorts given already SORTED and UNIQUE segments.

func appendMerge(target, sub []int) []int {

	lt, ls := len(target), len(sub)

	out := make([]int, 0, lt+ls)

	for x, y := 0, 0; x < lt || y < ls; {

		if x >= lt {

			out = append(out, sub[y:]...)

			break

		}

		if y >= ls {

			out = append(out, target[x:]...)

			break

		}

		xValue := target[x]

		yValue := sub[y]

		switch {

		case xValue == yValue:

			out = append(out, xValue)

			x++

			y++

		case xValue < yValue:

			out = append(out, xValue)

			x++

		case yValue < xValue:

			out = append(out, yValue)

			y++

		}

	}

	target = append(target[:0], out...)

	return target

}

func reverseSegments(input []int) {

	l := len(input)

	m := l / 2

	for i := 0; i < m; i++ {

		input[i], input[l-i-1] = input[l-i-1], input[i]

	}

}