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scm: Evaluate arguments of OR only once.

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* module/mes/base.mes (or): Evaluate arguments only once.
* module/mes/read-0.mes (or): Likewise.
* tests/base.test ("or only once"): Test it.
* module/mes/read-0-32.mo: Regenerate.
This commit is contained in:
Jan Nieuwenhuizen 2017-04-02 16:47:22 +02:00
parent 232e87bd9d
commit 08c04ff845
4 changed files with 24 additions and 8 deletions
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14
module/mes/base.mes
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@ -73,18 +73,20 @@
(define (command-line) %argv) (define (command-line) %argv)
(define-macro (or . x)
(if (null? x) #f
(if (null? (cdr x)) (car x)
(list 'if (car x) (car x)
(cons 'or (cdr x))))))
(define-macro (and . x) (define-macro (and . x)
(if (null? x) #t (if (null? x) #t
(if (null? (cdr x)) (car x) (if (null? (cdr x)) (car x)
(list 'if (car x) (cons 'and (cdr x)) (list 'if (car x) (cons 'and (cdr x))
#f)))) #f))))
(define-macro (or . x)
(if (null? x) #f
(if (null? (cdr x)) (car x)
(list (list 'lambda (list 'r)
(list 'if 'r 'r
(cons 'or (cdr x))))
(car x)))))
(define (and=> value procedure) (and value (procedure value))) (define (and=> value procedure) (and value (procedure value)))
(define eqv? eq?) (define eqv? eq?)

BIN
module/mes/read-0-32.mo
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7
module/mes/read-0.mes
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@ -198,8 +198,11 @@
(define-macro (or . x) (define-macro (or . x)
(if (null? x) #f (if (null? x) #f
(if (null? (cdr x)) (car x) (if (null? (cdr x)) (car x)
(list (quote if) (car x) (car x) (list (list (quote lambda) (list (quote r))
(cons (quote or) (cdr x)))))) (list (quote if) (quote r) (quote r)
(cons (quote or) (cdr x))))
(car x)))))
(define (not x) (define (not x)
(if x #f #t)) (if x #f #t))

11
tests/base.test
View file

@ -76,6 +76,17 @@ exit $?
(pass-if "or 3" (seq? (or #f (= 0 1) 3) 3)) (pass-if "or 3" (seq? (or #f (= 0 1) 3) 3))
(pass-if "or 4" (seq? (or (= 0 0) (= 0 1)) #t)) (pass-if "or 4" (seq? (or (= 0 0) (= 0 1)) #t))
(pass-if "or 5" (seq? (or (= 0 1) (= 0 0)) #t)) (pass-if "or 5" (seq? (or (= 0 1) (= 0 0)) #t))
(pass-if-equal "or only once"
1
(let ()
(define read
(let ((lst '(1 0)))
(lambda ()
(let ((r (car lst)))
(set! lst (cdr lst))
r))))
(or (read) #t)))
(pass-if "let" (seq? (let () 0) 0)) (pass-if "let" (seq? (let () 0) 0))
(pass-if "let 2" (seq? (let ((x 0)) x) 0)) (pass-if "let 2" (seq? (let ((x 0)) x) 0))
(pass-if "let 3" (seq? (let ((p 5) (q 6)) (+ p q)) 11)) (pass-if "let 3" (seq? (let ((p 5) (q 6)) (+ p q)) 11))