ref: fd3494af3e5209e7e74662bc4066b28f58ff49cc
dir: /libstd/intparse.myr/
use "chartype.use" use "die.use" use "hasprefix.use" use "option.use" use "types.use" use "utf.use" pkg std = generic intparsebase : (s : byte[:], base : int -> option(@a::(integral,numeric))) generic intparse : (s : byte[:] -> option(@a::(integral,numeric))) ;; generic intparse = {s var isneg isneg = false if hasprefix(s, "-") s = s[1:] isneg = true ;; 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 var c var v var cv : int32 v = 0 while s.len != 0 (c, s) = striter(s) if c == '_' continue ;; cv = charval(c, base) if cv >= 0 v *= (base castto(@a::(integral,numeric))) v += cv castto(@a::(integral,numeric)) else -> `None ;; ;; if isneg -> `Some -v else -> `Some v ;; }