36 lines
1.0 KiB
Common Lisp
36 lines
1.0 KiB
Common Lisp
;; put info string in permanent storage for later use
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(info 'make-Q
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"usage: (define q (make-Q)) ; (q '[top | empty? | pop | push value | to-list | from-list list])")
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;; make-Q
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(define (make-Q)
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(let ((q (make-vector 0)))
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(lambda (message . args)
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(case message
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((empty?) (vector-empty? q))
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((top) (if (vector-empty? q) (error 'Q:top:empty q) (vector-ref q 0)))
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((push) (vector-push q (car args)))
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((pop) (if (vector-empty? q) (error 'Q:pop:empty q) (vector-shift q)))
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((to-list) (vector->list q))
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((from-list) (set! q (list->vector (car args))) q )
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(else (info 'make-Q) (error "Q:bad message:" message )))))) ; display info if unknown message
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;;
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(define q (make-Q))
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(q 'empty?) → #t
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(q 'push 'first) → first
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(q 'push 'second) → second
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(q 'pop) → first
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(q 'pop) → second
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(q 'top)
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"💬 error: Q:top:empty #()"
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(q 'from-list '( 6 7 8)) → #( 6 7 8)
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(q 'top) → 6
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(q 'pop) → 6
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(q 'to-list)→ (7 8)
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(q 'delete)
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"💭 error: Q:bad message: delete"
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;; save make-Q
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(local-put 'make-Q)
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