Refactor emacs keybind

emacs.go

@@ -13,8 +13,6 @@ Moving the cursor
 * [x] Ctrl + e   Go to the End of the line (End)
 * [x] Ctrl + p   Previous command (Up arrow)
 * [x] Ctrl + n   Next command (Down arrow)
-* [ ] Alt + b   Back (left) one word
-* [ ] Alt + f   Forward (right) one word
 * [x] Ctrl + f   Forward one character
 * [x] Ctrl + b   Backward one character
 * [x] Ctrl + xx  Toggle between the start of line and current cursor position
@@ -23,8 +21,6 @@ Editing
 -------
 
 * [ ] Ctrl + L   Clear the Screen, similar to the clear command
-* [ ] Alt + Del Delete the Word before the cursor.
-* [ ] Alt + d   Delete the Word after the cursor.
 * [x] Ctrl + d   Delete character under the cursor
 * [x] Ctrl + h   Delete character before the cursor (Backspace)
 
@@ -32,97 +28,82 @@ Editing
 * [x] Ctrl + k   Cut the Line after the cursor to the clipboard.
 * [x] Ctrl + u   Cut/delete the Line before the cursor to the clipboard.
 
-* [ ] Alt + t   Swap current word with previous
 * [ ] Ctrl + t   Swap the last two characters before the cursor (typo).
 * [ ] Esc  + t   Swap the last two words before the cursor.
 
 * [ ] ctrl + y   Paste the last thing to be cut (yank)
-* [ ] Alt + u   UPPER capitalize every character from the cursor to the end of the current word.
-* [ ] Alt + l   Lower the case of every character from the cursor to the end of the current word.
-* [ ] Alt + c   Capitalize the character under the cursor and move to the end of the word.
-* [ ] Alt + r   Cancel the changes and put back the line as it was in the history (revert).
 * [ ] ctrl + _   Undo
 
 */
 
-var emacsKeyBindings = []KeyBind {
+var emacsKeyBindings = []KeyBind{
 	// Go to the End of the line
 	{
 		Key: ControlE,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			x := []rune(buf.Document().TextAfterCursor())
 			buf.CursorRight(len(x))
-			return buf
 		},
 	},
 	// Go to the beginning of the line
 	{
 		Key: ControlA,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			x := []rune(buf.Document().TextBeforeCursor())
 			buf.CursorLeft(len(x))
-			return buf
 		},
 	},
 	// Cut the Line after the cursor
 	{
 		Key: ControlK,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			x := []rune(buf.Document().TextAfterCursor())
 			buf.Delete(len(x))
-			return buf
 		},
 	},
 	// Cut/delete the Line before the cursor
 	{
 		Key: ControlU,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			x := []rune(buf.Document().TextBeforeCursor())
 			buf.DeleteBeforeCursor(len(x))
-			return buf
 		},
 	},
 	// Delete character under the cursor
 	{
 		Key: ControlD,
-		Fn: func(buf *Buffer) *Buffer {
-			if buf.Text() == "" {
-				return buf  // This means just exit.
+		Fn: func(buf *Buffer) {
+			if buf.Text() != "" {
+				buf.Delete(1)
 			}
-			buf.Delete(1)
-			return buf
 		},
 	},
 	// Backspace
 	{
 		Key: ControlH,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			buf.DeleteBeforeCursor(1)
-			return buf
 		},
 	},
 	// Right allow: Forward one character
 	{
 		Key: ControlF,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			buf.CursorRight(1)
-			return buf
 		},
 	},
 	// Left allow: Backward one character
 	{
 		Key: ControlB,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			buf.CursorLeft(1)
-			return buf
 		},
 	},
 	// Cut the Word before the cursor.
 	{
 		Key: ControlW,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			buf.DeleteBeforeCursor(len([]rune(buf.Document().GetWordBeforeCursor())))
-			return buf
 		},
 	},
 }

emacs_test.go

@@ -0,0 +1,32 @@
+package prompt
+
+import "testing"
+
+func TestEmacsKeyBindings(t *testing.T) {
+	buf := NewBuffer()
+	buf.InsertText("abcde", false, true)
+	if buf.CursorPosition != len("abcde") {
+		t.Errorf("Want %d, but got %d", len("abcde"), buf.CursorPosition)
+	}
+
+	// Go to the beginning of the line
+	applyEmacsKeyBind(buf, ControlA)
+	if buf.CursorPosition != 0 {
+		t.Errorf("Want %d, but got %d", 0, buf.CursorPosition)
+	}
+
+	// Go to the end of the line
+	applyEmacsKeyBind(buf, ControlE)
+	if buf.CursorPosition != len("abcde") {
+		t.Errorf("Want %d, but got %d", len("abcde"), buf.CursorPosition)
+	}
+}
+
+func applyEmacsKeyBind(buf *Buffer, key Key) {
+	for i := range emacsKeyBindings {
+		kb := emacsKeyBindings[i]
+		if kb.Key == key {
+			kb.Fn(buf)
+		}
+	}
+}

key_bind.go

@@ -1,6 +1,6 @@
 package prompt
 
-type KeyBindFunc func(*Buffer) *Buffer
+type KeyBindFunc func(*Buffer)
 
 type KeyBind struct {
 	Key Key
@@ -11,59 +11,52 @@ type KeyBindMode string
 
 const (
 	CommonKeyBind KeyBindMode = "common"
-	EmacsKeyBind KeyBindMode = "emacs"
+	EmacsKeyBind  KeyBindMode = "emacs"
 )
 
-var commonKeyBindings = []KeyBind {
+var commonKeyBindings = []KeyBind{
 	// Go to the End of the line
 	{
 		Key: End,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			x := []rune(buf.Document().TextAfterCursor())
 			buf.CursorRight(len(x))
-			return buf
 		},
 	},
 	// Go to the beginning of the line
 	{
 		Key: Home,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			x := []rune(buf.Document().TextBeforeCursor())
 			buf.CursorLeft(len(x))
-			return buf
 		},
 	},
 	// Delete character under the cursor
 	{
 		Key: Delete,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			buf.Delete(1)
-			return buf
 		},
 	},
 	// Backspace
 	{
 		Key: Backspace,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			buf.DeleteBeforeCursor(1)
-			return buf
 		},
 	},
 	// Right allow: Forward one character
 	{
 		Key: Right,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			buf.CursorRight(1)
-			return buf
 		},
 	},
 	// Left allow: Backward one character
 	{
 		Key: Left,
-		Fn: func(buf *Buffer) *Buffer {
+		Fn: func(buf *Buffer) {
 			buf.CursorLeft(1)
-			return buf
 		},
 	},
-
 }