Add NewStderrWriter (#102)

* Add NewStderrWriter

option.go

@@ -228,7 +228,7 @@ func OptionAddASCIICodeBind(b ...ASCIICodeBind) Option {
 
 // New returns a Prompt with powerful auto-completion.
 func New(executor Executor, completer Completer, opts ...Option) *Prompt {
-	defaultWriter := NewStandardOutputWriter()
+	defaultWriter := NewStdoutWriter()
 	registerConsoleWriter(defaultWriter)
 
 	pt := &Prompt{

output_posix.go

@@ -42,11 +42,25 @@ func (w *PosixWriter) Flush() error {
 
 var _ ConsoleWriter = &PosixWriter{}
 
-// NewStandardOutputWriter returns ConsoleWriter object to write to stdout.
+var (
+	// Deprecated: Please use NewStdoutWriter
+	NewStandardOutputWriter = NewStdoutWriter
+)
+
+// NewStdoutWriter returns ConsoleWriter object to write to stdout.
 // This generates VT100 escape sequences because almost terminal emulators
 // in POSIX OS built on top of a VT100 specification.
-func NewStandardOutputWriter() ConsoleWriter {
+func NewStdoutWriter() ConsoleWriter {
 	return &PosixWriter{
 		fd: syscall.Stdout,
 	}
 }
+
+// NewStderrWriter returns ConsoleWriter object to write to stderr.
+// This generates VT100 escape sequences because almost terminal emulators
+// in POSIX OS built on top of a VT100 specification.
+func NewStderrWriter() ConsoleWriter {
+	return &PosixWriter{
+		fd: syscall.Stderr,
+	}
+}

output_windows.go

@@ -27,10 +27,23 @@ func (w *WindowsWriter) Flush() error {
 
 var _ ConsoleWriter = &WindowsWriter{}
 
-// NewStandardOutputWriter returns ConsoleWriter object to write to stdout.
+var (
+	// Deprecated: Please use NewStdoutWriter
+	NewStandardOutputWriter = NewStdoutWriter
+)
+
+// NewStdoutWriter returns ConsoleWriter object to write to stdout.
 // This generates win32 control sequences.
-func NewStandardOutputWriter() ConsoleWriter {
+func NewStdoutWriter() ConsoleWriter {
 	return &WindowsWriter{
 		out: colorable.NewColorableStdout(),
 	}
 }
+
+// NewStderrWriter returns ConsoleWriter object to write to stderr.
+// This generates win32 control sequences.
+func NewStderrWriter() ConsoleWriter {
+	return &WindowsWriter{
+		out: colorable.NewColorableStderr(),
+	}
+}