ANSWER: LISP recursion using car/cdrsteemCreated with Sketch.

in common-lisp •  6 years ago 
  • Question: https://stackoverflow.com/questions/50243523
  • Snapshot:
  • See detailed step by step solution: https://github.com/sundawning/literate-programming/blob/master/english-to-nato-and-vice-verse.org
  • Why answer this homework?
    Why not.
  • Answer(There is actually no final answer, many places in the code can be improved.)
    (defun natos-englishs ()
      (list '(Alfa Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliet Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victor Whiskey Xray Zulu)
            '(A B C D E F G H I J K L M N O P Q R S T U V W X Z)))
    
    (defun convert-nato-english (item)
      (destructuring-bind (natos englishs)
          (natos-englishs)
        (cond ((member item natos)
               (nth (position item natos)
                    englishs))
              ((member item englishs)
               (nth (position item englishs)
                    natos))
              (t
               (error "Unvalid")))))
    
    (defun -mapcar (function list)
      (if (null list)
          nil
          (cons (funcall function
                         (car list))
                (-mapcar function
                         (cdr list)))))
    
    (defun format-lists (function lists)
      (format nil "~{~{~A~}~^ ~}"
              (-mapcar (lambda (list)
                         (-mapcar function
                                  list))
                       lists)))
    
    (defun conve (english-lists)
      (format-lists (lambda (english)
                      (string-capitalize
                       (write-to-string
                        (convert-nato-english english))))
                    english-lists))
    
    (defun convn (nato-lists)
      (format-lists (lambda (nato)
                      (write-to-string (convert-nato-english nato)
                                       :case :downcase))
                    nato-lists))  
    
    (list (conve '((P R O)
                   (L A N)))
          (convn '((Papa Romeo Oscar)
                   (Lima Alfa November))))
    
    ("PapaRomeoOscar LimaAlfaNovember" "pro lan")
    
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