如何消除 CLIPS 中的 if-then-else 以更好地优化代码

Question

我是CLIPS的新手，回溯范式确实让我头疼。

我得到了一个问题，我需要在哪里生成以下输出。

Q: Is the patient's temperature more than 39? [yes/no]: yes
    The patient has fever
Q: Does the patient sick over a month? [yes/no]: yes
    We suspect the patient has bacterial infection
Q: How about sore throat? [yes/no]: yes
    We believe the patient has strep throat

因此，根据需要，我定义了一些规则来使其正常工作。

(defrule rule_1
  (THE-PATIENT-HAS-A-SORE-THROAT)
  (WE-SUSPECT-A-BACTERIAL-INFECTION) =>
  (assert(WE-BELIEVE-THE-PATIENT-HAS-STREP-THROAT))
  (printout t "We believe the patient has strep throat" crlf))
(defrule rule_2
  (THE-PATIENT-TEMPERATURE-IS-40C) =>
  (assert(THE-PATIENT-HAS-A-FEVER)))
(defrule rule_3
  (THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH)
  (THE-PATIENT-HAS-A-FEVER) => 
  (assert(WE-SUSPECT-A-BACTERIAL-INFECTION)))
(defrule ask-sick
  (start-question) =>
  (printout t "Q: Is the patient's temperature more than 39? [yes/no]: ")
  (bind ?input (readline))
  (if (neq ?input "no")
    then
      (assert (THE-PATIENT-TEMPERATURE-IS-40C))
      (printout t "The patient has fever" crlf)
      (printout t "Q: Does the patient sick over a month? [yes/no]: ")
      (bind ?input2 (readline))
      (if (neq ?input2 "no")
        then
          (assert (THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH))
          (printout t "We suspect the patient has bacterial infection" crlf)
          (printout t "Q: How about sore throat? [yes/no]: ")
          (bind ?input3 (readline))
          (if (neq ?input3 "no")
            then
              (assert (THE-PATIENT-HAS-A-SORE-THROAT))
          )
      )
  )
)
(deffacts start
  (start-question)
)

最终，我确实让程序上线了。

问题是，在

规则ask-sick中，我不得不合并一堆if-then-else，以使程序在不太符合回溯范式的地方工作。

有人可以告诉我我应该如何优化它，因为它知道在哪里继续，规则 1 ->规则 2/规则 3 等。

Answer 1

这里有一种方法：

(deffunction ask-question (?question $?allowed-values)
   (printout t "Q: " ?question " [" (implode$ ?allowed-values) "] " )
   (bind ?answer (read))
   (if (lexemep ?answer) 
       then (bind ?answer (lowcase ?answer)))
   (while (not (member ?answer ?allowed-values)) do
      (printout t "Q: " ?question " [" (implode$ ?allowed-values) "] ")
      (bind ?answer (read))
      (if (lexemep ?answer) 
          then (bind ?answer (lowcase ?answer))))
   ?answer)
(deffunction yes-or-no (?question)
   (ask-question ?question yes no))
(defrule ask-temperature
  =>
  (bind ?input (yes-or-no "Is the patient's temperature more than 39?"))
  (assert (THE-PATIENT-TEMPERATURE-IS-40C ?input)))
(defrule ask-sick-for-over-a-month
   (THE-PATIENT-HAS-A-FEVER yes)
   =>  
   (bind ?input (yes-or-no "Does the patient sick over a month?"))
   (assert (THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH ?input)))
(defrule ask-sore-throat
   (WE-SUSPECT-A-BACTERIAL-INFECTION yes)
   =>
   (bind ?input (yes-or-no "How about sore throat?"))
   (assert (THE-PATIENT-HAS-A-SORE-THROAT ?input)))
(defrule conclude-fever
  (THE-PATIENT-TEMPERATURE-IS-40C yes) 
  =>
  (assert (THE-PATIENT-HAS-A-FEVER yes))
  (printout t "The patient has fever" crlf))
(defrule conclude-bacterial-infection
  (THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH yes)
  (THE-PATIENT-HAS-A-FEVER yes) 
  => 
  (assert (WE-SUSPECT-A-BACTERIAL-INFECTION yes))
  (printout t "We suspect the patient has bacterial infection" crlf))
(defrule conclude-strep-throat
  (THE-PATIENT-HAS-A-SORE-THROAT yes)
  (WE-SUSPECT-A-BACTERIAL-INFECTION yes) 
  =>
  (assert (WE-BELIEVE-THE-PATIENT-HAS-STREP-THROAT yes))
  (printout t "We believe the patient has strep throat" crlf))

另一个：

(deffunction ask-question (?question $?allowed-values)
   (printout t "Q: " ?question " [" (implode$ ?allowed-values) "] " )
   (bind ?answer (read))
   (if (lexemep ?answer) 
       then (bind ?answer (lowcase ?answer)))
   (while (not (member ?answer ?allowed-values)) do
      (printout t "Q: " ?question " [" (implode$ ?allowed-values) "] ")
      (bind ?answer (read))
      (if (lexemep ?answer) 
          then (bind ?answer (lowcase ?answer))))
   ?answer)
(deffunction yes-or-no (?question)
   (ask-question ?question yes no))
(deftemplate attribute
   (slot name)
   (slot value))
(deftemplate question
   (slot text)
   (slot attribute)
   (multislot precursors))
(deftemplate conclusion
   (slot text)
   (slot attribute)
   (multislot precursors))
(deffacts questions
   (question
      (text "Is the patient's temperature more than 39?")
      (attribute THE-PATIENT-TEMPERATURE-IS-40C))
   (question
      (text "Does the patient sick over a month?")
      (attribute THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH)
      (precursors THE-PATIENT-HAS-A-FEVER))
   (question
      (text "How about sore throat?")
      (attribute THE-PATIENT-HAS-A-SORE-THROAT)
      (precursors WE-SUSPECT-A-BACTERIAL-INFECTION)))
(deffacts conclusions
   (conclusion
      (text "The patient has fever")
      (attribute THE-PATIENT-HAS-A-FEVER)
      (precursors THE-PATIENT-TEMPERATURE-IS-40C))
   (conclusion
      (text "We suspect the patient has bacterial infection")
      (attribute WE-SUSPECT-A-BACTERIAL-INFECTION)
      (precursors THE-PATIENT-HAS-BEEN-SICK-OVER-A-MONTH THE-PATIENT-HAS-A-FEVER))
   (conclusion
      (text "We believe the patient has strep throat")
      (attribute WE-BELIEVE-THE-PATIENT-HAS-STREP-THROAT)
      (precursors THE-PATIENT-HAS-A-SORE-THROAT WE-SUSPECT-A-BACTERIAL-INFECTION)))
(defrule ask-question   
    (question (text ?text)
              (attribute ?attr))
    (forall (question (attribute ?attr)
                      (precursors $? ?pre $?))
            (attribute (name ?pre)
                       (value yes)))
    =>
    (bind ?input (yes-or-no ?text))
    (assert (attribute (name ?attr) (value ?input))))
(defrule conclude
    (conclusion (text ?text)
                (attribute ?attr))
    (forall (conclusion (attribute ?attr)
                        (precursors $? ?pre $?))
            (attribute (name ?pre)
                       (value yes)))
    =>
    (assert (attribute (name ?attr) (value yes)))
    (printout t ?text crlf))