Version: 2.0.7
# stable-2.0, around commit: 3d2b267
# ./configure (no arguments)
hash.test has a failing case:
FAIL: tests/hash.test: hash-set and hash-ref:
;; 1/2 and 2/4 are equal? and eqv? but not eq?
(pass-if (equal? #f
(let ((table (make-hash-table)))
(hashq-set! table 1/2 (quote foo))
(hashq-ref table 1/2))))
which may be due to the optimizer or other component working on
literals:
scheme@(guile-user)> (eqv? 1/2 2/4)
$1 = #t
scheme@(guile-user)> (eq? 1/2 2/4)
$2 = #f
scheme@(guile-user)> ,optimize (eq? 1/2 2/4)
$3 = #f
scheme@(guile-user)> (hashq 1/2 31)
$4 = 6
scheme@(guile-user)> (hashq 2/4 31)
$5 = 20
scheme@(guile-user)> ,optimize (hashq 2/4 31)
$6 = (hashq 1/2 31)
scheme@(guile-user)> ;; uh oh
The ramifications reach beyond hash functions:
scheme@(guile-user)> (define x 1/2)
scheme@(guile-user)> (eq? x 2/4)
$7 = #f
scheme@(guile-user)> ,optimize (eq? x 2/4)
$8 = (eq? x 1/2)
scheme@(guile-user)> (define y 2/4)
scheme@(guile-user)> (eq? x y)
$9 = #f
scheme@(guile-user)> ,optimize (define y 2/4)
$10 = (define y 1/2)
I recall some discussion where it was made clear that literals can not
be assumed eq?, and that *at least* eqv? should be used to compare
numeric values unless they are known to be the same value (i.e. ‘(define
y x) (eq? x y)’).
Is that right? This particular test and some others properly should
fade away then, or at least drop the eq-case.
