I search online documentation but haven't found the way. For a rule like below (taken from the calculator example), I want to refer to external code.
expressions
: NUMBER
{$$ = new My.Number(yytext);}
To achieve that, I need to require('My') somewhere in the jison file but when I try to add require, it is removed from the js file generated.
You can add another section after your grammar, like this:
%%
const My = require('My')