unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
fn isUnreserved(c: u8) bool
fn isUnreserved(c: u8) bool { return switch (c) { 'A'...'Z', 'a'...'z', '0'...'9', '-', '.', '_', '~' => true, else => false, }; }