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72 irasnyd 1 
;Written By: Ira Snyder
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;Due Date:   02-28-2005
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;Homework #: HW12
108 ira 4 
;License: Public Domain
72 irasnyd 5 
 
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;;; This is the generic implementation of the recursive schema OP-SOME.
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;;; It takes 3 parameters:
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;;;   CONDITION: when this is true, the operation happens on that element
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;;;   OP: the operation to happen on the values that satisfy CONDITION
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;;;   ARG: the list of items on which to operate
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;;;
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;;; Example: (OP-SOME #'oddp #'sq '(1 2 3 4 5)) -> (1 2 9 4 25)
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(defun OP-SOME (CONDITION OP ARG)
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  (cond
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    ((null ARG)                    nil)
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    ((funcall CONDITION (car ARG)) (cons (funcall OP (car ARG))
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                                         (OP-SOME CONDITION OP (cdr ARG))))
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    (t                             (cons (car ARG)
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                                         (OP-SOME CONDITION OP (cdr ARG))))
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  )
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)
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;;; Returns the square of the number passed in as a parameter.
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;;; This is to aid in testing of OP-SOME
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(defun SQ (NUM)
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  (* NUM NUM)
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)
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