32 lines
761 B
Plaintext
32 lines
761 B
Plaintext
(define-module set
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:imports ("cxr.slime")
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:exports (make find contains? insert!)
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(define key-not-found-index -1)
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(define (make . vals)
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(set-type!
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(if vals
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(list vals)
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'(()))
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:set))
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(define (find set val)
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(let ((values (car set)))
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(define (inner values current-index)
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(cond ((null? values) key-not-found-index)
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((= (car values) val) current-index)
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(else (inner (cdr values) (+ 1 current-index)))))
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(inner values 0)))
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(define (contains? set val)
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(unless (= (find set val) key-not-found-index)
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t))
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(define (insert! set value)
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(unless (contains? set value)
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(set! set (pair (pair value (first set)) ()))
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(set-type! set :set))
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set)
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)
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