我工作的一个决策引擎/规则评估引擎。例如：

I am working on a decision engine / rule evaluation engine. For example:

输入：客户和所有客户做的犯罪

Input: Customer and all the offences done by the customer

输出：罪行后果

一个样本情况是：

输入：客户（的Jhonny Chimpo，999-00-1111），犯罪（布罗克窗口，老板打耳光，脚踢团队主管在他的腹股沟）

Input: Customer(Jhonny Chimpo, 999-00-1111), Offences ( Broke window, slapped boss, kicked team lead in his groin)

输出：获取解雇

所以我想写的一块code评估基于每个进攻和进攻相结合的规则不同的罪行。目前的code是if和else语句的只是一个迷宫。我相信这样的业务问题很常见。通常用什么样的设计/企业模式来解决这样的问题呢？

So the piece of code I want to write evaluates different offences based on rules for each offence and combined offence. The current code is just a maze of if and else statements. I am sure such business problems are common. What design/enterprise pattern is usually used to solve a problem like this?

这是不是规范的模式？我想code到对扩展开放，干净而有弹性。

Is it the specification pattern? I want the code to be open for extension, clean and flexible.

推荐答案

基本上业务规则看起来像

Basically business rules look like

forall rules:
  if <condition> then doAction();

怎么样使用严重程度评分，也许是多余的频繁恶人奖金分类的所有罪行，有些罪行可能成为时间限制和任何必需的。

What about categorizing all offences by severity using scores, perhaps extra bonus for frequent "evil-doers", some offences may become time-barred and whatever required.

然后，一个算法的草图可以是：

Then a rough draft of an algorithm could be:

这是简单的用数据结构，而不是很多（可能是深度嵌套）if..then..else的事情。

This would be straight forward using data structures instead of many (possibly deeply nested) if..then..else things.