11 lines
246 B
Racket
11 lines
246 B
Racket
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(define (find-symbol id tree)
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(call/cc
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(lambda (exit)
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(define (find tree)
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(if (pair? tree)
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(or (find (car tree)) (find (cdr tree)))
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(if (eq? tree id) (exit #t) #f)))
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(find tree))))
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