Description
Embedding is Gos answer to subclasses. There’s one caveat:
There’s an important way in which embedding differs from subclassing. When we embed a type, the methods of that type become methods of the outer type, but when they are invoked the receiver of the method is the inner type, not the outer one.
Interfaces
type Reader interface {
Read(p []byte) (n int, err error)
}
type Writer interface {
Write(p []byte) (n int, err error)
}
type ReadWriter interface {
Reader
Writer
}ReadWriter “extends” Reader & Writer in the example above.
Structs
type ReadWriter struct {
*Reader // *bufio.Reader
*Writer // *bufio.Writer
}
func (rw *ReadWriter) Read(p []byte) (n int, err error) {
return rw.reader.Read(p)
}