WASM instead of Lua

[SSkeptix]

Hi, I didn’t find a better place to ask this question.
I have a short technical question for the developers:
If you had to create the modding system again today, would you prefer to use WASM instead of Lua, or is Lua still the better choice for Factorio

[h.q.droid]

Not a Factorio dev, but I won't consider WASM for a modding system:

- Bad development ergonomics. You have to compile something else into WASM, so it would be clunky to run something immediate from the map editor.
- Bad performance. WASM trades high interfacing overhead for computational efficiency. The evidence is WASM being much slower at DOM manipulation than vanilla Javascript. For a mod it's usually counter-productive since modding is mostly interfacing.

Do you have some computation-heavy modding ideas in mind? Maybe they can be implemented using some creative shader passes?

[SSkeptix]

Thanks for the great answer! I hadn’t thought about the performance cost between the WASM and engine boundaries.
No, this question isn’t about any specific modding ideas — I’m a developer (but not a game dev). I'm just curious about how things work in the game development world or maybe I should say performance-optimized world.

[Rseding91]

I would be interested in trying C# as a modding language alternative, but I haven’t looked into the cons of it, and I’m unsure if it supports running on non-windows.

[Tertius]

Rimworld modding is C# based, however as far as I understand Rimworld itself is programmed in C# (Unity engine) and the modding "API" is just a hook into the class and object structure directly. It's directly patching the game, not going through a well defined modding api. A different concept than Factorio. And also as far as I know, mods are supported on all the platforms Rimworld is running on: Windows, Mac, Linux. Consoles are supported as well, but I don't know about mods for these.