Question:
why is in the following example the custom-printer called twice?
#lang racket
(define n 0)
(letrec-values
(((printer)
(λ (obj port mode)
(set! n (add1 n))
(fprintf port "#<x:~s>" (name obj))))
((id constr pred acc mut)
(make-struct-type 'x #f 1 0 #f
(list (cons prop:custom-write printer))))
((name) (make-struct-field-accessor acc 0 'name)))
(constr 'y)) ; -> #<x:y>
n ; -> 2
;Done with
;DrRacket, version 6.2.0.5--2015-07-06(d6fa581/a) [3m].
;Language: racket [custom]; memory limit: 2000 MB.
Best wishes, Jos Koot
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