Files
advent-of-code-2021/common.scm
2021-12-07 11:21:21 +01:00

10 lines
366 B
Scheme

; returns a list of numbers parsed from the first line of the file,
; separated by commas
(define (read-comma-separated-numbers file)
(let loop [(draws '()) (n 0)]
(let [(c (get-char file))]
(cond
[(char=? c #\,) (loop (cons n draws) 0)]
[(char-whitespace? c) (reverse (cons n draws))]
[else (loop draws (+ (* n 10) (string->number (string c))))]))))