feat: add flyweight

Author: mohuishou

11_flyweight/flyweight.go

@@ -0,0 +1,58 @@
+package flyweight
+
+var units = map[int]*ChessPieceUnit{
+	1: {
+		ID:    1,
+		Name:  "車",
+		Color: "red",
+	},
+	2: {
+		ID:    2,
+		Name:  "炮",
+		Color: "red",
+	},
+	// ... 其他棋子
+}
+
+// ChessPieceUnit 棋子享元
+type ChessPieceUnit struct {
+	ID    uint
+	Name  string
+	Color string
+}
+
+// NewChessPieceUnit 工厂
+func NewChessPieceUnit(id int) *ChessPieceUnit {
+	return units[id]
+}
+
+// ChessPiece 棋子
+type ChessPiece struct {
+	Unit *ChessPieceUnit
+	X    int
+	Y    int
+}
+
+// ChessBoard 棋局
+type ChessBoard struct {
+	chessPieces map[int]*ChessPiece
+}
+
+// NewChessBoard 初始化棋盘
+func NewChessBoard() *ChessBoard {
+	board := &ChessBoard{chessPieces: map[int]*ChessPiece{}}
+	for id := range units {
+		board.chessPieces[id] = &ChessPiece{
+			Unit: NewChessPieceUnit(id),
+			X:    0,
+			Y:    0,
+		}
+	}
+	return board
+}
+
+// Move 移动棋子
+func (c *ChessBoard) Move(id, x, y int) {
+	c.chessPieces[id].X = x
+	c.chessPieces[id].Y = y
+}

11_flyweight/flyweight_test.go

@@ -0,0 +1,17 @@
+package flyweight
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewChessBoard(t *testing.T) {
+	board1 := NewChessBoard()
+	board1.Move(1, 1, 2)
+	board2 := NewChessBoard()
+	board2.Move(2, 2, 3)
+
+	assert.Equal(t, board1.chessPieces[1].Unit, board2.chessPieces[1].Unit)
+	assert.Equal(t, board1.chessPieces[2].Unit, board2.chessPieces[2].Unit)
+}

readme.md

@@ -43,7 +43,7 @@ go 设计模式实现，包含 23 种常见的设计模式实现
 
 - [门面模式(Facade Design Pattern)](./09_facade) [![](https://img.shields.io/badge/BLOG-%E7%82%B9%E5%87%BB%E6%9F%A5%E7%9C%8B-success?style=flat&cacheSeconds=360000)](https://lailin.xyz/post/facade.html)
 - [组合模式(Composite Design Pattern)](./10_composite) [![](https://img.shields.io/badge/BLOG-%E7%82%B9%E5%87%BB%E6%9F%A5%E7%9C%8B-success?style=flat&cacheSeconds=360000)](https://lailin.xyz/post/composite.html)
-- 享元模式
+- [享元模式(Flyweight Design Pattern)](./11_flyweight) [![](https://img.shields.io/badge/BLOG-%E7%82%B9%E5%87%BB%E6%9F%A5%E7%9C%8B-success?style=flat&cacheSeconds=360000)](https://lailin.xyz/post/flyweight.html)
 
 ## 行为型模式