Highlight.js Theme for EBNF

[commonsensesoftware]

Problem

Extended Backus-Naur Form (EBNF) is supported by highlight.js, but the default theme has the appearance of no syntax highlighting. This likely applies to BNF and ABNF also.

Here are some examples:

GitHub

letter = "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L" | "M" |
         "N" | "O" | "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z" |
         "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | "j" | "k" | "l" | "m" |
         "n" | "o" | "p" | "q" | "r" | "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z" ;
digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
identifier = letter , { letter | digit | "-" | "_"  } ;
topic = identifier , "/" , identifier ;
values = identifier , { ":" , identifier } ;
key = topic , "/" values ;

VS Code

MdBook

This is using the Ayu theme, but reverting to the default theme appears to produce similar results.

Proposed Solution

There's probably a way to custom the default them to make it work, but I'm 100% sure how. Ideally, the default theme should retain minimal syntax highlighting.

Notes

No response