ref: 7ec5af48e7c7fa40c494b5572fcfa04d3a998cba
dir: /lib/std/intparse.myr/
use "chartype" use "die" use "hasprefix" use "option" use "striter" use "types" use "utf" pkg std = generic intparsebase : (s : byte[:], base : int -> option(@a)) :: integral,numeric @a generic intparse : (s : byte[:] -> option(@a)) :: integral,numeric @a ;; generic intparse = {s var isneg isneg = false if hasprefix(s, "-") s = s[1:] isneg = true ;; if s.len == 0 -> `None ;; if hasprefix(s, "0x") -> doparse(s[2:], isneg, 16) elif hasprefix(s, "0o") -> doparse(s[2:], isneg, 8) elif hasprefix(s, "0b") -> doparse(s[2:], isneg, 2) else -> doparse(s, isneg, 10) ;; } generic intparsebase = {s, base var isneg isneg = false if hasprefix(s, "-") s = s[1:] isneg = true ;; -> doparse(s, isneg, base) } generic doparse = {s, isneg, base -> option(@a) :: integral,numeric @a var v var cv : int32 v = 0 for c : std.bychar(s) if c == '_' continue ;; cv = charval(c, base) if cv >= 0 v *= (base : @a) v += (cv : @a) else -> `None ;; ;; if isneg -> `Some -v else -> `Some v ;; }