[QUESTION] support custom types (i256)

[spebern]

Question

What is the best way of using the lexical optimized parsing routines for a custom type (arbitrary size integers e.g. 256bit)?

Background: In arrow the decimal type uses an underlying i256 (https://github.com/apache/arrow-rs/blob/7bf7ea5e341c15dbd8653b16413459f5fa4784eb/arrow-buffer/src/bigint.rs#LL26-L29C2). However, lexical only supports the rust native types (as far as I understand it). What is the best way of parsing into arbitrary size integers/byte arrays using lexical?

Thanks!