# [racket] Implementing an equal? method for a class

For 81 slots, I'd actually use a (define b (make-vector 81 0)) instead and use an access polynomial. I am almost certain that it is faster.
On Jul 29, 2012, at 6:00 PM, Eli Barzilay wrote:
>* Yesterday, Gregory Woodhouse wrote:
*>>* (define b(make-vector 9 (make-vector 9 0)))
*>*
*>* BTW, this is wrong -- it builds a vector of 9 zeros, then uses that
*>* same vector 9 times:
*>*
*>* -> (define x (make-vector 2 (make-vector 2 0)))
*>* -> x
*>* '#(#(0 0) #(0 0))
*>* -> (vector-set! (vector-ref x 0) 0 1)
*>* -> x
*>* '#(#(1 0) #(1 0))
*>* -> (print-graph #t)
*>* -> x
*>* '#(#0=#(1 0) #0#)
*>*
*>* --
*>* ((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay:
*>* http://barzilay.org/ Maze is Life!
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