From 68147da8e92e5fb190cf91d3417a4ee8007cadf3 Mon Sep 17 00:00:00 2001
From: c-bata <contact@c-bata.link>
Date: Sun, 9 Jul 2017 22:55:59 +0900
Subject: [PATCH] Improve left and right moving

---
 main.go          | 10 ++++++++--
 prompt/buffer.go | 12 ++++++++----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/main.go b/main.go
index fe125df..8778dc0 100644
--- a/main.go
+++ b/main.go
@@ -43,13 +43,19 @@ func main() {
 		} else if ac.Key == prompt.Enter || ac.Key == prompt.ControlJ {
 			buffer.InsertText("\n", false, true)
 		} else if ac.Key == prompt.Left {
-			buffer.CursorLeft(1)
+			l := buffer.CursorLeft(1)
+			if l == 0 {
+				continue
+			}
 			out.CursorDown(1)
 			out.CursorBackward(1)
 			out.EraseDown()
 			out.CursorUp(1)
 		} else if ac.Key == prompt.Right {
-			buffer.CursorRight(1)
+			l := buffer.CursorRight(1)
+			if l == 0 {
+				continue
+			}
 			out.CursorDown(1)
 			out.EraseDown()
 			out.CursorForward(1)
diff --git a/prompt/buffer.go b/prompt/buffer.go
index 6c57c9a..139f54e 100644
--- a/prompt/buffer.go
+++ b/prompt/buffer.go
@@ -99,13 +99,17 @@ func (b *Buffer) setDocument(d *Document) {
 }
 
 // CursorLeft move to left on the current line.
-func (b *Buffer) CursorLeft(count int) {
-	b.CursorPosition += b.Document().GetCursorLeftPosition(count)
+func (b *Buffer) CursorLeft(count int) int {
+	l := b.Document().GetCursorLeftPosition(count)
+	b.CursorPosition += l
+	return -l
 }
 
 // CursorRight move to right on the current line.
-func (b *Buffer) CursorRight(count int) {
-	b.CursorPosition += b.Document().GetCursorRightPosition(count)
+func (b *Buffer) CursorRight(count int) int {
+	l := b.Document().GetCursorRightPosition(count)
+	b.CursorPosition += l
+	return l
 }
 
 // CursorUp move cursor to the previous line.