attach last key stroke to document

buffer.go

@@ -13,6 +13,7 @@ type Buffer struct {
 	cursorPosition  int
 	cacheDocument   *Document
 	preferredColumn int // Remember the original column for the next up/down movement.
+	lastKeyStroke   Key
 }
 
 // Text returns string of the current line.
@@ -30,6 +31,7 @@ func (b *Buffer) Document() (d *Document) {
 			cursorPosition: b.cursorPosition,
 		}
 	}
+	b.cacheDocument.lastKey = b.lastKeyStroke
 	return b.cacheDocument
 }
 

document.go

@@ -16,6 +16,7 @@ type Document struct {
 	// So if Document is "日本(cursor)語", cursorPosition is 2.
 	// But DisplayedCursorPosition returns 4 because '日' and '本' are double width characters.
 	cursorPosition int
+	lastKey        Key
 }
 
 // NewDocument return the new empty document.
@@ -26,6 +27,11 @@ func NewDocument() *Document {
 	}
 }
 
+// LastKeyStroke return the last key pressed in this document.
+func (d *Document) LastKeyStroke() Key {
+	return d.lastKey
+}
+
 // DisplayCursorPosition returns the cursor position on rendered text on terminal emulators.
 // So if Document is "日本(cursor)語", DisplayedCursorPosition returns 4 because '日' and '本' are double width characters.
 func (d *Document) DisplayCursorPosition() int {

prompt.go

@@ -98,7 +98,7 @@ func (p *Prompt) Run() {
 
 func (p *Prompt) feed(b []byte) (shouldExit bool, exec *Exec) {
 	key := GetKey(b)
-
+	p.buf.lastKeyStroke = key
 	// completion
 	completing := p.completion.Completing()
 	p.handleCompletionKeyBinding(key, completing)