Golang设计模式，组合模式

两个例子，一个组合运动员，一个树。

package composite

// region start composite swimmer demo
type ITrainer interface {
    Train()
}

type ISwimmer interface {
    Swim()
}

type CompositeSwimmer struct {
    ITrainer
    ISwimmer
}

type Athlete struct{}

func (a *Athlete) Train() {
    println("Training")
}

type Swimmer struct{}

func (b *Swimmer) Swim() {
    println("Swimming")
}

// endregion end composite swimmer demo

// region start tree demo
type Tree struct {
    LeafValue int
    Left      *Tree
    Right     *Tree
}

// endregion end tree demo

测试程序

package composite

import (
    "testing"
)

func TestComposite_Swimmer(t *testing.T) {
    swimmer := CompositeSwimmer{
        ITrainer: &Athlete{},
        ISwimmer: &Swimmer{},
    }

    swimmer.Train()
    swimmer.Swim()
}

func TestTree(t *testing.T) {
    root := Tree{
        LeafValue: 0,
        Left: &Tree{
            LeafValue: 20,
            Left:      nil,
            Right:     nil,
        },
        Right: &Tree{
            LeafValue: 20,
            Left:      nil,
            Right: &Tree{
                LeafValue: 8,
                Left:      nil,
                Right:     nil,
            },
        },
    }

    println(root.Right.Right.LeafValue)
}