produce grammar as ECMAScript module?

[franktip]

Hi, is it possible to have nearleyc produce an ECMAScript module, in which the the produced grammar is the default export? This would make it easier to use the generated parsers in a server-side setting. Currently, the generated parser contains:

if (typeof module !== 'undefined'&& typeof module.exports !== 'undefined') { module.exports = grammar; } else { window.grammar = grammar; }

which does not work on platforms where the "window" variable is not defined.

Right now, I have a workaround that relies on manual editing the generated parser, which is not ideal, because I have to repeat the edit every time the grammar changes.

[supposedly]

Just found out by accident that Nearley actually does do this: https://github.com/kach/nearley/blob/0313b2c2d96bd93d5282def0bb46351e3455f8a0/lib/generate.js#L143-L153

You can activate it by sticking @preprocessor esmodule or @preprocessor module at the top of your .ne grammar.

If you need it to work a bit differently (for example, using named exports instead of the default export) and you don't mind a bit of dirty code, you could create your own local version of the nearleyc script and monkey-patch that generate object with your own preprocessor(s). Just make sure to replace all require('../foo/bar') with require('nearley/foo/bar') and you're set!