Acornima - Esprima.NET with an acornjs-based parser

[adams85]

Hi there,

Recently I've been working on a fork of Esprima.NET: https://github.com/adams85/acornima

As a matter of fact, it's more of a rewrite than a fork as the most significant part was replaced with an implementation based on another parser, acornjs.

However, the "garnish" (public API, sourcegen, AST, etc.) has been borrowed from Esprima.NET. Although a lot of the borrowed code has been refactored/improved heavily, there are bits that are identical to the original. Which raises some questions around licensing:

1. From what I understand, Esprima.NET's BSD 3-Clause license allows me to create such a fork as long as I meet the listed conditions. Please let me know if I get it wrong.

2. If my fork turns to be ok, I need to license that as well. I'm considering also adopting the BSD 3-Clause license as it seems a reasonable one. Would this be ok with you?

3. I googled a bit on how to handle the original license in practice. This sounds like a solid advice:

   The easiest way is to have a single LICENSE file that describes only your ... license, and then have a separate NOTICE file that says:

   This software is a fork of the following software, originally licensed under the BSD 3 clause license:
   <put copyright line and name of software for original repo here, maybe also include a link to the original repo>
   A copy of the BSD-3 license can be found here: (<link or paste license text).

   Would this be an acceptable solution to you as well?

@sebastienros, as the owner of the Esprima.NET project, could you please answer these questions?

[sebastienros]

You are all good. Take a screenshot of this message and save it in a drawer for when your lawyer asks for it ;)

If you want to mention the esprima-dotnet project/license in a NOTICE.txt (in source code only, so GitHub) that would be the best way of action to comply with the license terms. If you don't, I don't care. You've worked so much on esprima-dotnet it's almost more your project than mine, but not as much as Marko's. We might just need it in case others do also fork your project and miss the relationship.

[adams85]

Thanks for the quick response, I'll do exactly so.

Take a screenshot of this message and save it in a drawer for when your lawyer asks for it ;)

😄

[sebastienros]

The perf difference is minor, but I can already see @lahma getting teased by that and accepting the challenge

[adams85]

Oh, regarding this I forgot to mention: of course, you are also allowed to port any improved or new code back to Esprima if you wish.

[lahma]

I'm super happy that @adams85 took this challenge. I've envied acorn and it's conformance and it's been hard to sync esprima-dotnet changes based on how acorn does things with different models and parsing (it being fully compliant and JS esprima lacking behind).

Acorn being actively developed it's surely easier target even for Jint especially as the AST models are quite the same. Maybe something for v4 😉

[sebastienros]

Please have some fun and try to port Jint to Acornima if that makes sense. Unless @adams85 beats you to it.