How do i convert c++ class to lisp?

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How do i convert c++ class to lisp?

Postby joeish80829 » Sat Dec 07, 2013 6:37 pm

How do i convert c++ class to lisp?


I am new to c++ classes and have 400 lines of basic c++ classes to convert and I was hoping some one could show me how to convert this c++ class to lisp. I know about defclass and defmethod but I was hoping to have a quick example of a proffessional conversion I could use as a template to match my conversion of the rest of the code against...

here is the class

Code: Select all
class TrainingData
{
public:
    TrainingData(const string filename);
    bool isEof(void) { return m_trainingDataFile.eof(); }
    void getTopology(vector<unsigned> &topology);

    // Returns the number of input values read from the file:
    unsigned getNextInputs(vector<double> &inputVals);
    unsigned getTargetOutputs(vector<double> &targetOutputVals);

private:
    ifstream m_trainingDataFile;
};
joeish80829
 
Posts: 153
Joined: Tue Sep 03, 2013 5:32 am

Re: How do i convert c++ class to lisp?

Postby marcoxa » Sun Dec 08, 2013 3:40 am

With care and understanding that C++ "hiding rules" are not the same as CL. Plus, and this is the biggie, methods (or "member functions" in C++) are *NOT* part of a class definition. CLOS classes are essentially "data only classes" (something that some SW engineer does not grasp as useful, but I digress :twisted: )

A per your case...

Code: Select all
#|
class TrainingData
{
public:
    TrainingData(const string filename);
    bool isEof(void) { return m_trainingDataFile.eof(); }
    void getTopology(vector<unsigned> &topology);

    // Returns the number of input values read from the file:
    unsigned getNextInputs(vector<double> &inputVals);
    unsigned getTargetOutputs(vector<double> &targetOutputVals);

private:
    ifstream m_trainingDataFile;
};
|#

(defclass training-data ()
  ((training-data-stream :reader training-data-stream
                         :writer |set training data stream (using a funky name)|
                         :initarg :training-data-stream))
  )


;;; initialize-instance :after -- This is your 'constructor' code.

(defmethod initialize-instance :after ((td training-data)
                                       &key
                                       training-data-stream
                                       &allow-other-keys)
  ;; Initialize the slot.

  ;; Note that 'opening' a stream, as it is implied by the C++ class
  ;; definiton and leaking the open stream handle is very impolite.

  (let ((is (etypecase training-data-stream
              ((string pathname) (open training-data-stream :direction :input))
              (stream (if (input-stream-p training-data-stream)
                          training-data-stream
                          (error "Not an input stream.")))))
        )
    (|set training data stream (using a funky name)| is td)
    ))


(defgeneric is-eof (td)
  (:method ((td training-data))
   ;; Are you sure you want this method?
   ))


(defgeneric get-topology (td))

(defgeneric get-next-inputs (td))

(defgeneric get-target-outputs (td))


;;; Later, or elsewhere...

(defmethod get-topology ((td training-data))
  ;; Get the 'topology'
  ;; yadda-yadda-yadda

  topology ; a (VECTOR UNSIGNED-BYTE *)
  )


(defmethod get-next-inputs ((td training-data))
  ;; Get the next inputs

  (values
   n-next-inputs
   next-inputs ; a (VECTOR DOUBLE-FLOAT *)
   )
  )


(defmethod get-target-outputs ((td training-data))
  ;; Get the next inputs

  (values
   n-targets
   target-outputs ; a (VECTOR DOUBLE-FLOAT *)
   )
  )
Marco Antoniotti
marcoxa
 
Posts: 69
Joined: Thu Aug 14, 2008 6:31 pm


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