refactor

example/main.go

@@ -10,13 +10,12 @@ import (
 )
 
 func main() {
-	t, err := readline.NewTerminal()
+	l, err := readline.New("> ")
 	if err != nil {
 		panic(err)
 	}
-	defer t.Close()
+	defer l.Close()
 
-	l := t.NewReadline("> ")
 	log.SetOutput(l.Stderr())
 	for {
 		line, err := l.Readline()

history.go

@@ -1,56 +1,56 @@
 package readline
 
-func (l *Readline) PrevHistory() []rune {
-	if l.current == nil {
+func (o *Operation) PrevHistory() []rune {
+	if o.current == nil {
 		return nil
 	}
-	current := l.current.Prev()
+	current := o.current.Prev()
 	if current == nil {
 		return nil
 	}
-	l.current = current
+	o.current = current
 	return current.Value.([]rune)
 }
 
-func (l *Readline) NextHistory() []rune {
-	if l.current == nil {
+func (o *Operation) NextHistory() []rune {
+	if o.current == nil {
 		return nil
 	}
-	current := l.current.Next()
+	current := o.current.Next()
 	if current == nil {
 		return nil
 	}
-	l.current = current
+	o.current = current
 	return current.Value.([]rune)
 }
 
-func (l *Readline) NewHistory(current []rune) {
-	l.UpdateHistory(current)
-	if l.current != l.history.Back() {
+func (o *Operation) NewHistory(current []rune) {
+	o.UpdateHistory(current)
+	if o.current != o.history.Back() {
 		// move history item to current command
-		l.history.Remove(l.current)
-		use := l.current.Value.([]rune)
-		l.current = l.history.Back()
-		l.UpdateHistory(use)
+		o.history.Remove(o.current)
+		use := o.current.Value.([]rune)
+		o.current = o.history.Back()
+		o.UpdateHistory(use)
 	}
 
 	// push a new one to commit current command
-	l.PushHistory(nil)
+	o.PushHistory(nil)
 }
 
-func (l *Readline) UpdateHistory(s []rune) {
-	if l.current == nil {
-		l.PushHistory(s)
+func (o *Operation) UpdateHistory(s []rune) {
+	if o.current == nil {
+		o.PushHistory(s)
 		return
 	}
-	r := l.current.Value.([]rune)
-	l.current.Value = append(r[:0], s...)
+	r := o.current.Value.([]rune)
+	o.current.Value = append(r[:0], s...)
 }
 
-func (l *Readline) PushHistory(s []rune) {
+func (o *Operation) PushHistory(s []rune) {
 	// copy
 	newCopy := make([]rune, len(s))
 	copy(newCopy, s)
-	elem := l.history.PushBack(newCopy)
-	l.current = elem
+	elem := o.history.PushBack(newCopy)
+	o.current = elem
 }

operation.go

@@ -0,0 +1,131 @@
+package readline
+
+import (
+	"container/list"
+	"io"
+	"os"
+)
+
+type Operation struct {
+	r       *os.File
+	t       *Terminal
+	buf     *RuneBuffer
+	outchan chan []rune
+
+	history *list.List
+	current *list.Element
+}
+
+const (
+	CharLineStart = 0x1
+	CharLineEnd   = 0x5
+	CharNext      = 0xe
+	CharPrev      = 0x10
+	CharBackward  = 0x2
+	CharForward   = 0x6
+	CharEscape    = 0x7f
+	CharEnter     = 0xd
+	CharEnter2    = 0xa
+)
+
+type wrapWriter struct {
+	r      *Operation
+	target io.Writer
+}
+
+func (w *wrapWriter) Write(b []byte) (int, error) {
+	buf := w.r.buf
+	buf.Clean()
+	n, err := w.target.Write(b)
+	w.r.buf.RefreshSet(0, 0)
+	return n, err
+}
+
+func NewOperation(r *os.File, t *Terminal, prompt string) *Operation {
+	op := &Operation{
+		r:       r,
+		t:       t,
+		buf:     NewRuneBuffer(t, prompt),
+		outchan: make(chan []rune),
+		history: list.New(),
+	}
+	go op.ioloop()
+	return op
+}
+
+func (l *Operation) ioloop() {
+	for {
+		r := l.t.ReadRune()
+		switch r {
+		case MetaNext:
+			l.buf.MoveToNextWord()
+		case MetaPrev:
+			l.buf.MoveToPrevWord()
+		case MetaDelete:
+			l.buf.DeleteWord()
+		case CharLineStart:
+			l.buf.MoveToLineStart()
+		case CharLineEnd:
+			l.buf.MoveToLineEnd()
+		case KeyDelete:
+			l.buf.Delete()
+		case CharEscape:
+			l.buf.BackEscape()
+		case CharEnter, CharEnter2:
+			l.buf.WriteRune('\n')
+			data := l.buf.Reset()
+			data = data[:len(data)-1] // trim \n
+			l.outchan <- data
+			l.NewHistory(data)
+		case CharBackward:
+			l.buf.MoveBackward()
+		case CharForward:
+			l.buf.MoveForward()
+		case CharPrev:
+			buf := l.PrevHistory()
+			if buf != nil {
+				l.buf.Set(buf)
+			}
+		case CharNext:
+			buf := l.NextHistory()
+			if buf != nil {
+				l.buf.Set(buf)
+			}
+		case KeyInterrupt:
+			l.buf.WriteString("^C\n")
+			l.outchan <- nil
+		default:
+			l.buf.WriteRune(r)
+		}
+		l.UpdateHistory(l.buf.Runes())
+	}
+}
+
+func (l *Operation) Stderr() io.Writer {
+	return &wrapWriter{target: os.Stderr, r: l}
+}
+
+func (l *Operation) String() (string, error) {
+	r, err := l.Runes()
+	if err != nil {
+		return "", err
+	}
+	return string(r), nil
+}
+
+func (l *Operation) Runes() ([]rune, error) {
+	l.buf.Refresh(0, 0) // print prompt
+	r := <-l.outchan
+	if r == nil {
+		return nil, io.EOF
+	}
+	return r, nil
+}
+
+func (l *Operation) Slice() ([]byte, error) {
+	r, err := l.Runes()
+	if err != nil {
+		return nil, err
+	}
+	return []byte(string(r)), nil
+}

readline.go

@@ -1,123 +1,36 @@
 package readline
 
-import (
-	"container/list"
-	"io"
-	"os"
-)
+import "io"
 
-type Readline struct {
-	r       *os.File
-	t       *Terminal
-	buf     *RuneBuffer
-	outchan chan []rune
-
-	history *list.List
-	current *list.Element
-}
-
-const (
-	CharLineStart = 0x1
-	CharLineEnd   = 0x5
-	CharNext      = 0xe
-	CharPrev      = 0x10
-	CharBackward  = 0x2
-	CharForward   = 0x6
-	CharEscape    = 0x7f
-	CharEnter     = 0xd
-	CharEnter2    = 0xa
-)
-
-type wrapWriter struct {
-	r      *Readline
-	target io.Writer
-}
-
-func (w *wrapWriter) Write(b []byte) (int, error) {
-	buf := w.r.buf
-	buf.Clean()
-	n, err := w.target.Write(b)
-	w.r.buf.RefreshSet(0, 0)
-	return n, err
+type Instance struct {
+	t *Terminal
+	o *Operation
 }
 
-func newReadline(r *os.File, t *Terminal, prompt string) *Readline {
-	rl := &Readline{
-		r:       r,
-		t:       t,
-		buf:     NewRuneBuffer(t, prompt),
-		outchan: make(chan []rune),
-		history: list.New(),
+func New(prompt string) (*Instance, error) {
+	t, err := NewTerminal()
+	if err != nil {
+		return nil, err
 	}
-	go rl.ioloop()
-	return rl
+	rl := t.Readline(prompt)
+	return &Instance{
+		t: t,
+		o: rl,
+	}, nil
 }
 
-func (l *Readline) ioloop() {
-	for {
-		r := l.t.ReadRune()
-		switch r {
-		case MetaNext:
-			l.buf.MoveToNextWord()
-		case MetaPrev:
-			l.buf.MoveToPrevWord()
-		case MetaDelete:
-			l.buf.DeleteWord()
-		case CharLineStart:
-			l.buf.MoveToLineStart()
-		case CharLineEnd:
-			l.buf.MoveToLineEnd()
-		case KeyDelete:
-			l.buf.Delete()
-		case CharEscape:
-			l.buf.BackEscape()
-		case CharEnter, CharEnter2:
-			l.buf.WriteRune('\n')
-			data := l.buf.Reset()
-			data = data[:len(data)-1] // trim \n
-			l.outchan <- data
-			l.NewHistory(data)
-		case CharBackward:
-			l.buf.MoveBackward()
-		case CharForward:
-			l.buf.MoveForward()
-		case CharPrev:
-			buf := l.PrevHistory()
-			if buf != nil {
-				l.buf.Set(buf)
-			}
-		case CharNext:
-			buf := l.NextHistory()
-			if buf != nil {
-				l.buf.Set(buf)
-			}
-		case KeyInterrupt:
-			l.buf.WriteString("^C\n")
-			l.outchan <- nil
-		default:
-			l.buf.WriteRune(r)
-		}
-		l.UpdateHistory(l.buf.Runes())
-	}
+func (i *Instance) Stderr() io.Writer {
+	return i.o.Stderr()
 }
 
-func (l *Readline) Stderr() io.Writer {
-	return &wrapWriter{target: os.Stderr, r: l}
+func (i *Instance) Readline() (string, error) {
+	return i.o.String()
 }
 
-func (l *Readline) Readline() (string, error) {
-	r, err := l.ReadlineSlice()
-	if err != nil {
-		return "", err
-	}
-	return string(r), nil
+func (i *Instance) ReadSlice() ([]byte, error) {
+	return i.o.Slice()
 }
 
-func (l *Readline) ReadlineSlice() ([]byte, error) {
-	l.buf.Refresh(0, 0)
-	r := <-l.outchan
-	if r == nil {
-		return nil, io.EOF
-	}
-	return []byte(string(r)), nil
+func (i *Instance) Close() error {
+	return i.t.Close()
 }

terminal.go

@@ -56,8 +56,8 @@ func (t *Terminal) PrintRune(r rune) {
 	fmt.Fprintf(os.Stdout, "%c", r)
 }
 
-func (t *Terminal) NewReadline(prompt string) *Readline {
-	return newReadline(os.Stdin, t, prompt)
+func (t *Terminal) Readline(prompt string) *Operation {
+	return NewOperation(os.Stdin, t, prompt)
 }
 
 func (t *Terminal) ReadRune() rune {