14 lines
348 B
Text
14 lines
348 B
Text
(defun enqueue (x xs)
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(cons x xs))
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(defun dequeue (xs)
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(declare (xargs :guard (and (consp xs)
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(true-listp xs))))
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(if (or (endp xs) (endp (rest xs)))
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(mv (first xs) nil)
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(mv-let (x ys)
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(dequeue (rest xs))
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(mv x (cons (first xs) ys)))))
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(defun empty (xs)
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(endp xs))
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