CLIPS 计数匹配模式的事实或模板实例

【问题标题】：CLIPS counting facts or template instances that match the patternCLIPS 计数匹配模式的事实或模板实例
【发布时间】：2014-09-24 00:57:42
【问题描述】：

首先我声明：

(deftemplate worker （插槽编号（输入字符串）（默认？DERIVE））

(时薪（类型浮动）（默认？DERIVE）））

然后我补充：

(assert(worker(id "a")(salary 30.0)))

(assert(worker(id "b")(salary 40.0)))

(assert(worker(id "c")(salary 60.0)))

(assert(worker(id "d")(salary 70.0)))

(assert(worker(id "e")(salary 10.0)))

我如何计算我有多少“工人”？

例如，我如何计算有多少工人的薪水超过 30？

【问题讨论】：

标签： clips expert-system

【解决方案1】：

使用事实集查询函数：

CLIPS> 
(deftemplate worker
   (slot id (type STRING) (default ?DERIVE))
   (slot salary (type FLOAT) (default ?DERIVE)))
CLIPS> (assert (worker (id "a") (salary 30.0)))
<Fact-1>
CLIPS> (assert (worker (id "b") (salary 40.0)))
<Fact-2>
CLIPS> (assert (worker (id "c") (salary 60.0)))
<Fact-3>
CLIPS> (assert (worker (id "d") (salary 70.0)))
<Fact-4>
CLIPS> (assert (worker (id "e") (salary 10.0)))
<Fact-5>
CLIPS> (find-all-facts ((?f worker)) (> ?f:salary 30.0))
(<Fact-2> <Fact-3> <Fact-4>)
CLIPS> (length$ (find-all-facts ((?f worker)) (> ?f:salary 30.0)))
3
CLIPS> (do-for-all-facts ((?f worker)) (> ?f:salary 30.0) (printout t ?f:id crlf))
b
c
d
CLIPS>

【讨论】：