Replace rope with lineArray

cmd/micro/loc.go

@@ -0,0 +1,120 @@
+package main
+
+// FromCharPos converts from a character position to an x, y position
+func FromCharPos(loc int, buf *Buffer) Loc {
+	charNum := 0
+	x, y := 0, 0
+
+	lineLen := Count(buf.Line(y)) + 1
+	for charNum+lineLen <= loc {
+		charNum += lineLen
+		y++
+		lineLen = Count(buf.Line(y)) + 1
+	}
+	x = loc - charNum
+
+	return Loc{x, y}
+}
+
+// ToCharPos converts from an x, y position to a character position
+func ToCharPos(start Loc, buf *Buffer) int {
+	x, y := start.X, start.Y
+	loc := 0
+	for i := 0; i < y; i++ {
+		// + 1 for the newline
+		loc += Count(buf.Line(i)) + 1
+	}
+	loc += x
+	return loc
+}
+
+// Loc stores a location
+type Loc struct {
+	X, Y int
+}
+
+// LessThan returns true if b is smaller
+func (l Loc) LessThan(b Loc) bool {
+	if l.Y < b.Y {
+		return true
+	}
+	if l.Y == b.Y && l.X < b.X {
+		return true
+	}
+	return false
+}
+
+// GreaterThan returns true if b is bigger
+func (l Loc) GreaterThan(b Loc) bool {
+	if l.Y > b.Y {
+		return true
+	}
+	if l.Y == b.Y && l.X > b.X {
+		return true
+	}
+	return false
+}
+
+// GreaterEqual returns true if b is greater than or equal to b
+func (l Loc) GreaterEqual(b Loc) bool {
+	if l.Y > b.Y {
+		return true
+	}
+	if l.Y == b.Y && l.X > b.X {
+		return true
+	}
+	if l == b {
+		return true
+	}
+	return false
+}
+
+// LessEqual returns true if b is less than or equal to b
+func (l Loc) LessEqual(b Loc) bool {
+	if l.Y < b.Y {
+		return true
+	}
+	if l.Y == b.Y && l.X < b.X {
+		return true
+	}
+	if l == b {
+		return true
+	}
+	return false
+}
+
+func (l Loc) right(n int, buf *Buffer) Loc {
+	if l == buf.End() {
+		return l
+	}
+	var res Loc
+	if l.X < Count(buf.Line(l.Y)) {
+		res = Loc{l.X + 1, l.Y}
+	} else {
+		res = Loc{0, l.Y + 1}
+	}
+	return res
+}
+func (l Loc) left(n int, buf *Buffer) Loc {
+	if l == buf.Start() {
+		return l
+	}
+	var res Loc
+	if l.X > 0 {
+		res = Loc{l.X - 1, l.Y}
+	} else {
+		res = Loc{Count(buf.Line(l.Y - 1)), l.Y - 1}
+	}
+	return res
+}
+
+func (l Loc) Move(n int, buf *Buffer) Loc {
+	if n > 0 {
+		return l.right(n, buf)
+	}
+	return l.left(Abs(n), buf)
+}
+
+// func (l Loc) DistanceTo(b Loc, buf *Buffer) int {
+//
+// }