Replace rope with lineArray

cmd/micro/lineArray.go

@@ -0,0 +1,133 @@
+package main
+
+import (
+	"bytes"
+	"unicode/utf8"
+)
+
+func runeToByteIndex(n int, txt []byte) int {
+	if n == 0 {
+		return 0
+	}
+
+	count := 0
+	i := 0
+	for len(txt) > 0 {
+		_, size := utf8.DecodeRune(txt)
+
+		txt = txt[size:]
+		count += size
+		i++
+
+		if i == n {
+			break
+		}
+	}
+	return count
+}
+
+type LineArray struct {
+	lines [][]byte
+}
+
+func NewLineArray(text []byte) *LineArray {
+	la := new(LineArray)
+	split := bytes.Split(text, []byte("\n"))
+	la.lines = make([][]byte, len(split))
+	for i := range split {
+		la.lines[i] = make([]byte, len(split[i]))
+		copy(la.lines[i], split[i])
+	}
+
+	return la
+}
+
+func (la *LineArray) String() string {
+	return string(bytes.Join(la.lines, []byte("\n")))
+}
+
+func (la *LineArray) NewlineBelow(y int) {
+	la.lines = append(la.lines, []byte(" "))
+	copy(la.lines[y+2:], la.lines[y+1:])
+	la.lines[y+1] = []byte("")
+}
+
+func (la *LineArray) insert(pos Loc, value []byte) {
+	x, y := runeToByteIndex(pos.X, la.lines[pos.Y]), pos.Y
+	// x, y := pos.x, pos.y
+	for i := 0; i < len(value); i++ {
+		if value[i] == '\n' {
+			la.Split(Loc{x, y})
+			x = 0
+			y++
+			continue
+		}
+		la.insertByte(Loc{x, y}, value[i])
+		x++
+	}
+}
+
+func (la *LineArray) insertByte(pos Loc, value byte) {
+	la.lines[pos.Y] = append(la.lines[pos.Y], 0)
+	copy(la.lines[pos.Y][pos.X+1:], la.lines[pos.Y][pos.X:])
+	la.lines[pos.Y][pos.X] = value
+}
+
+func (la *LineArray) JoinLines(a, b int) {
+	la.insert(Loc{len(la.lines[a]), a}, la.lines[b])
+	la.DeleteLine(b)
+}
+
+func (la *LineArray) Split(pos Loc) {
+	la.NewlineBelow(pos.Y)
+	la.insert(Loc{0, pos.Y + 1}, la.lines[pos.Y][pos.X:])
+	la.DeleteToEnd(Loc{pos.X, pos.Y})
+}
+
+func (la *LineArray) remove(start, end Loc) string {
+	sub := la.Substr(start, end)
+	startX := runeToByteIndex(start.X, la.lines[start.Y])
+	endX := runeToByteIndex(end.X, la.lines[end.Y])
+	if start.Y == end.Y {
+		la.lines[start.Y] = append(la.lines[start.Y][:startX], la.lines[start.Y][endX:]...)
+	} else {
+		for i := start.Y + 1; i <= end.Y-1; i++ {
+			la.DeleteLine(i)
+		}
+		la.DeleteToEnd(Loc{startX, start.Y})
+		la.DeleteFromStart(Loc{endX - 1, start.Y + 1})
+		la.JoinLines(start.Y, start.Y+1)
+	}
+	return sub
+}
+
+func (la *LineArray) DeleteToEnd(pos Loc) {
+	la.lines[pos.Y] = la.lines[pos.Y][:pos.X]
+}
+
+func (la *LineArray) DeleteFromStart(pos Loc) {
+	la.lines[pos.Y] = la.lines[pos.Y][pos.X+1:]
+}
+
+func (la *LineArray) DeleteLine(y int) {
+	la.lines = la.lines[:y+copy(la.lines[y:], la.lines[y+1:])]
+}
+
+func (la *LineArray) DeleteByte(pos Loc) {
+	la.lines[pos.Y] = la.lines[pos.Y][:pos.X+copy(la.lines[pos.Y][pos.X:], la.lines[pos.Y][pos.X+1:])]
+}
+
+func (la *LineArray) Substr(start, end Loc) string {
+	startX := runeToByteIndex(start.X, la.lines[start.Y])
+	endX := runeToByteIndex(end.X, la.lines[end.Y])
+	if start.Y == end.Y {
+		return string(la.lines[start.Y][startX:endX])
+	}
+	var str string
+	str += string(la.lines[start.Y][startX:]) + "\n"
+	for i := start.Y + 1; i <= end.Y-1; i++ {
+		str += string(la.lines[i]) + "\n"
+	}
+	str += string(la.lines[end.Y][:endX])
+	return str
+}