I made some effort trying to come up with one myself, but didn’t manage to do so, so just reprinting some simples one here:
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| #lang racket
; https://www.nyx.net/~gthompso/self_scheme.txt
((lambda (x) `(,x ',x))
'(lambda (x) `(,x ',x)))
((lambda (x) `(,(reverse x) ',x))
'(`(,(reverse x) ',x) (x) lambda))
(define (my-eval e)
(eval e (make-base-namespace)))
(define quine-1
((lambda (x) `(,x ',x))
'(lambda (x) `(,x ',x))))
(define quine-2
((lambda (x) `(,(reverse x) ',x))
'(`(,(reverse x) ',x) (x) lambda)))
(define (is-quine? e)
(and (equal? e (my-eval e))
(equal? e (my-eval (my-eval e)))))
(is-quine? quine-1)
(is-quine? quine-2)
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