策略模式Lua实现

Strategy = {}

ConcreteStrategyA = {}

ConcreteStrategyB = {}

ConcreteStrategyC = {}

Context = {strategy = nil}

function Strategy:new(o)
o = o or {}
setmetatable(o,self)
self.__index = self
return o;
end

function Strategy:AlgorithmInterface()
print("逻辑接口")
end

ConcreteStrategyA = Strategy:new()

function ConcreteStrategyA:AlgorithmInterface()
print("具体策略A")
end

function Context:new(o,s)
o = o or {}
setmetatable(o,self)
self.__index = self
if s ~= nil then
o.strategy = s
end
return o;
end

function Context:ContextInterface()
self.strategy:AlgorithmInterface()
end

context = Context:new({},ConcreteStrategyA:new())
context:ContextInterface()

上面的代码的输出结果是：具体的策略A

如果你把

function ConcreteStrategyA:AlgorithmInterface()

注释掉，输出的结果应该就会是：逻辑接口。

有兴趣的同学也可以将ConcreteStrategyB,ConcreteStrategyC加上去，练练手。

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