pub const Element = struct {
    identifier: Identifier,
    slice: Slice,

    pub const Slice = struct {
        start: u32,
        end: u32,

        pub const empty: Slice = .{ .start = 0, .end = 0 };
    };

    pub const ParseError = error{CertificateFieldHasInvalidLength};

    pub fn parse(bytes: []const u8, index: u32) Element.ParseError!Element {
        var i = index;
        const identifier = @as(Identifier, @bitCast(bytes[i]));
        i += 1;
        const size_byte = bytes[i];
        i += 1;
        if ((size_byte >> 7) == 0) {
            return .{
                .identifier = identifier,
                .slice = .{
                    .start = i,
                    .end = i + size_byte,
                },
            };
        }

        const len_size = @as(u7, @truncate(size_byte));
        if (len_size > @sizeOf(u32)) {
            return error.CertificateFieldHasInvalidLength;
        }

        const end_i = i + len_size;
        var long_form_size: u32 = 0;
        while (i < end_i) : (i += 1) {
            long_form_size = (long_form_size << 8) | bytes[i];
        }

        return .{
            .identifier = identifier,
            .slice = .{
                .start = i,
                .end = i + long_form_size,
            },
        };
    }
}