Question

我一直在教授计算机科学。最常教授的语言是C＃，C ++，Java，Python等。我每学期都会添加Perl，Ruby等其他语言的示例，以便学生可以看到跨语言的共性。我一直在尝试使用Common Lisp，并且不得不承认，近40年来我第一次用语言碰壁了。

Common Lisp让我难以获得一个简单的示例程序来编译和运行。我需要在ideone.com上运行代码，以便学生可以自己自己尝试并进行更改以查看会发生什么。我非常感谢能得到任何帮助......一整周的奋斗就是我所能做的一切。

以下是代码：

(defclass employee() ;;class definition header
    ((empid :accessor employee-empid;;member variable accessible and preset
        :initform 230
        :initarg :empid)
      (name :accessor employee-name;;member variable accessible and preset
        :intform 'bill
        :intarg :name)
      (pay  :accessor employee-pay;;member variable accessible and preset
        :initform 10
        :initarg :pay)))

(defmethod infofun ( (p employee));;member method to allow two member vars to be changed
    (print "The Worker: " : (employee-name p))
    (setf (employee-pay p))
    (setf (employee-empid p)))

(setq w1(make-instance 'employee :empid 100 :name 'worker1 :pay 47));;instance of class for w1
(setq w2(make-instance 'employee :empid 102 :name 'worker1 :pay 57));;instance of class for w2
(setq w3(make-instance 'employee :empid 103 :name 'worker1 :pay 67));;instance of class for w3

(describe w1);;get general info from List about the instance w1
(describe w2)
(describe w3)

(infofun w1);;run the member function, change the member vars
(infofun w2)
(infofun w3)

(setf (employee-pay w1) 147);;change a member var by code


(describe w1);;look at w1 again and note the values
(infofun w1);;change w1 again
(describe w1);;look at w1 one more time and check the new values

我希望有人能帮助我。

谢谢

Dr t

Answer 1

您的代码中存在拼写错误：intarg而不是initarg，与intform相同。

这一行

    (print "The Worker: " : (employee-name p))

在midle有一个冒号。

setf之类的(setf (employee-pay p))需要两个参数，正如您之后所做的那样：(setf (employee-pay p) SOMETHING)。

我只能通过写一个真正的IDE来看到它。

我建议你得到Portacle，这是一个可以直接安装的便携式多平台Common Lisp开发环境：下载并运行。您将能够使用错误消息尝试您的代码。 Portacle出货Emacs25，SBCL，Quicklisp，Slime和Git。

祝你好运！

Answer 2

我讨厌回答我自己的问题，但这里有......

尽管我告诉自己不这样做，但昨晚我花了几个小时在这个工作。如果您是程序员，那么您就知道它是什么样的。最后灯亮了，我意识到我的类头有一个'类型'，但解释器没有地方绑定地址。我刚刚添加了一个地方。然后我能够做出实例！我还简化了类定义并取出了所有'冒险'代码，直到它运行。然后我回去添加行为。

这是我想出的。我正在研究一个更好的版本。

  (defclass employee-worker ()
    (person-name empid));;extremely simple common lisp class definition

(defparameter *worker*(make-instance 'employee-worker));;constructor call for the first instance
(setf (slot-value *worker* 'person-name) "Joe Brown")
(setf (slot-value *worker* 'empid) "234")

(defparameter *worker2*(make-instance 'employee-worker));;constructor call for the second instance
(setf (slot-value *worker2* 'person-name) "John Brown")
(setf (slot-value *worker2* 'empid) "235")

(print "The first worker is: ")
(print (slot-value *worker* 'person-name))
(print "And his employee ID number is:  ")
(print (slot-value *worker* 'empid))
(print "")
(print"The second worker is:  ")
(print (slot-value *worker2* 'person-name))
(print "And his employee ID number is:  ")
(print (slot-value *worker2* 'empid))

(setf (slot-value *worker* 'person-name) "Joe Green");;change the slot values for the first worker
(setf (slot-value *worker* 'empid) "432")

(print "The first worker is: ");;look at the first worker again to see the changes
(print (slot-value *worker* 'person-name))
(print "And his employee ID number is:  ")
(print (slot-value *worker* 'empid))

Success time: 0 memory: 38056 signal:0

"The first worker is: " 
"Joe Brown" 
"And his employee ID number is:  " 
"234" 
"" 
"The second worker is:  " 
"John Brown" 
"And his employee ID number is:  " 
"235" 
"The first worker is: " 
"Joe Green" 
"And his employee ID number is:  " 
"432" 

I appreciate everyone helping.

由于博士

在ideone.com上运行Common Lisp？

2 个答案: