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Since your BIOS is being a Basic Inducer Of Suffering, here is an implementation of >>57 to eliminate delete-duplicates, in the MIT/GNU Scheme 9.1.1 from the Ubuntu LTS, while keeping as much of your structure as possible:
(define (posts-range range)
(define (expand-range x)
(cond ((> (length x) 1)
(let* ((a (string->number (car x)))
(b (string->number (cadr x)))
(low (if (> a *max-posts*) *max-posts* a))
(high (if (> b *max-posts*) *max-posts* b))
(count (+ (- high low) 1)))
(if (> high low)
(lambda () (iota count low))
(lambda () (list low)))))
(else (let* ((a (string->number (car x)))
(low (if (> a *max-posts*) *max-posts* a)))
(lambda () (list low))))))
(define (invoke-loop-set vector lamb)
(for-each (lambda (e) (vector-set! vector e #t))
(lamb)))
(let* ((r1 (string-split range #\,))
(r2 (map (lambda (x) (string-split x #\-)) r1))
(r3 (map expand-range r2))
(vec (make-vector (+ *max-posts* 1) #f)))
(for-each (lambda (e) (invoke-loop-set vec e))
r3)
vec))Here are some tests, keeping in mind that posts-range runs after the regex match:
1 ]=> (posts-range "1,3,5,7,290-300")
;Value 13: #(#f #t #f #t #f #t #f #t #f #f #f #f [...] #f #f #f #f #t #t #t #t #t #t #t #t #t #t #t)
1 ]=> (posts-range "1-9999999999")
;Value 14: #(#f #t #t #t #t #t #t #t #t #t #t #t [...] #t #t #t #t #t #t #t #t #t #t #t #t #t #t #t)
1 ]=> (define fulltest (apply string-append (cons "1-300" (make-list (quotient (- 4096 7) 6) ",1-300"))))At this point fulltest is >>50.
1 ]=> (posts-range fulltest)
;Value 17: #(#f #t #t #t #t #t #t #t #t #t #t #t [...] #t #t #t #t #t #t #t #t #t #t #t #t #t #t #t)
1 ]=> (define (timeit proc)
(with-timings proc
(lambda (run-time gc-time real-time)
(write (internal-time/ticks->seconds run-time))
(write-char #\space)
(write (internal-time/ticks->seconds gc-time))
(write-char #\space)
(write (internal-time/ticks->seconds real-time))
(newline))))
1 ]=> (timeit (lambda () (posts-range "1,3,5,7,290-300")))
0. 0. 0.
1 ]=> (timeit (lambda () (posts-range fulltest)))
.04 0. .044