ref: d4862853ca810b97d1adc2944f32975fd4a5018f
dir: /lib/std/chomp.myr/
use "hasprefix" pkg std = const chomp : (str : byte[:]#, pfx : byte[:] -> bool) ;; const chomp = {str, pfx if std.hasprefix(str#, pfx) str# = str#[pfx.len:] -> true else -> false ;; }