Reorganize file structure

cmd/micro/buffer/loc.go

@@ -0,0 +1,118 @@
+package buffer
+
+import (
+	"unicode/utf8"
+
+	"github.com/zyedidia/micro/cmd/micro/util"
+)
+
+// 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
+	}
+	return l.Y == b.Y && l.X < b.X
+}
+
+// GreaterThan returns true if b is bigger
+func (l Loc) GreaterThan(b Loc) bool {
+	if l.Y > b.Y {
+		return true
+	}
+	return l.Y == b.Y && l.X > b.X
+}
+
+// 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
+	}
+	return l == b
+}
+
+// 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
+	}
+	return l == b
+}
+
+// The following functions require a buffer to know where newlines are
+
+// Diff returns the distance between two locations
+func Diff(a, b Loc, buf *Buffer) int {
+	if a.Y == b.Y {
+		if a.X > b.X {
+			return a.X - b.X
+		}
+		return b.X - a.X
+	}
+
+	// Make sure a is guaranteed to be less than b
+	if b.LessThan(a) {
+		a, b = b, a
+	}
+
+	loc := 0
+	for i := a.Y + 1; i < b.Y; i++ {
+		// + 1 for the newline
+		loc += utf8.RuneCount(buf.LineBytes(i)) + 1
+	}
+	loc += utf8.RuneCount(buf.LineBytes(a.Y)) - a.X + b.X + 1
+	return loc
+}
+
+// This moves the location one character to the right
+func (l Loc) right(buf *Buffer) Loc {
+	if l == buf.End() {
+		return Loc{l.X + 1, l.Y}
+	}
+	var res Loc
+	if l.X < utf8.RuneCount(buf.LineBytes(l.Y)) {
+		res = Loc{l.X + 1, l.Y}
+	} else {
+		res = Loc{0, l.Y + 1}
+	}
+	return res
+}
+
+// This moves the given location one character to the left
+func (l Loc) left(buf *Buffer) Loc {
+	if l == buf.Start() {
+		return Loc{l.X - 1, l.Y}
+	}
+	var res Loc
+	if l.X > 0 {
+		res = Loc{l.X - 1, l.Y}
+	} else {
+		res = Loc{utf8.RuneCount(buf.LineBytes(l.Y - 1)), l.Y - 1}
+	}
+	return res
+}
+
+// Move moves the cursor n characters to the left or right
+// It moves the cursor left if n is negative
+func (l Loc) Move(n int, buf *Buffer) Loc {
+	if n > 0 {
+		for i := 0; i < n; i++ {
+			l = l.right(buf)
+		}
+		return l
+	}
+	for i := 0; i < util.Abs(n); i++ {
+		l = l.left(buf)
+	}
+	return l
+}