Doesn't accept codepoints >255 such as %xD7FF

[arp242]

It currently fails with ErrTooLargeNumeral for values >255 such as a = %xD7FF or a = %x80-D7FF.

As near as I can tell ABNF has no such restriction; the ABNF for it is simply 1*HEXDIG, and as I read sections 2.3 and 2.4 you can use any encoding scheme you want (such as Unicode).

It currently fails to parse the TOML ABNF due to this: https://github.com/toml-lang/toml/blob/main/toml.abnf

[pandatix]

Hi, thanks for reporting this. Indeed the RFC 5234 does not seem to limit to [0:255] numerals encoded whatever the terminal in use.
This interpretation comes from bap which does not handle these large numerals too.

(tested on IETF BAP online)

In any case this implementation does not deal with big integers but rather native integers. I can improve the implementation to handle bits over a uint64 (thus limit to %xFFFFFFFFFFFFFFFF and alternatives), but it won't be a perfect solve due to no boundary defined in Section 4.

Echoes #44

[arp242]

Well, at least that confirms that it's valid/legal :-)

You don't need BigInt by the way, or even uint64, just int32 (rune) should be enough to hold all of Unicode. That should (probably) be enough for our lifetimes.