Make it easier to distinguish between Read and Write in the DebugCallback (#31)

Author: belak

conn.go

@@ -12,7 +12,7 @@ type Conn struct {
 	// DebugCallback is a callback for every line of input and
 	// output. It is meant for debugging and is not guaranteed to
 	// be stable.
-	DebugCallback func(line string)
+	DebugCallback func(operation, line string)
 
 	// Internal things
 	conn io.ReadWriteCloser
@@ -23,7 +23,7 @@ type Conn struct {
 func NewConn(rwc io.ReadWriteCloser) *Conn {
 	// Create the client
 	c := &Conn{
-		func(line string) {},
+		func(operation, line string) {},
 		rwc,
 		bufio.NewReader(rwc),
 	}
@@ -34,7 +34,7 @@ func NewConn(rwc io.ReadWriteCloser) *Conn {
 // Write is a simple function which will write the given line to the
 // underlying connection.
 func (c *Conn) Write(line string) {
-	c.DebugCallback("--> " + line)
+	c.DebugCallback("write", line)
 	c.conn.Write([]byte(line))
 	c.conn.Write([]byte("\r\n"))
 }
@@ -58,7 +58,7 @@ func (c *Conn) ReadMessage() (*Message, error) {
 		return nil, err
 	}
 
-	c.DebugCallback("<-- " + strings.TrimRight(line, "\r\n"))
+	c.DebugCallback("read", strings.TrimRight(line, "\r\n"))
 
 	// Parse the message from our line
 	m := ParseMessage(line)