Duktape VS Wren

Fast math optimizations can break code like this by breaking isNaN.

I was porting a C++ project to a certain platform - and that platform enabled a -ffast-math equivalent by default in Release (but not Debug) builds! This broke duktape, a JS engine said project embedded, in some nasty and subtle ways. Instead of storing a number/pointer/??? (8 bytes) + type tag (4? bytes) for each dynamically typed JS value, duktape can bit-pack values into a single 8 byte "double" value by storing object/string handles as NaN values - this isn't an uncommon trick for dynamically typed scripting stuff:

https://github.com/svaarala/duktape/blob/c3722054ea4a4e50f48...

Naturally, the -ffast-math equivalent broke isNaN checks, which caused random object/string handles to be mistakenly reinterpreted as "numbers" - but only in Release builds, for this one particular platform, in one rarely taken branch, so neither QA nor CI caught it, leading to hours of manufacturing a repro case, stepping through an absurd amount of code, and then finally looking at the default build rules and facepalming.

Cursing the platform vendor under my breath, I overrode the defaults to align with the defaults of every other config x platform combination we already had: no fast math. If you want those optimizations, use SSE-friendly NaN-avoiding intrinsics - or, if you must use the compiler flags, ensure you do so consistently across build configs and platforms, perhaps limited to a few TUs or modules if possible. This allows you to have a chance at using your Debug builds to debug the resulting "optimizations".

Sure. For example, DukTape is an implementation of Javascript designed to be embedded in other projects. Google's V8 Javascript engine (used in Chrome), can also be embedded, see Node.Js for example.

- Duktape (4.8k stars)

My first choices would be Wren or Gravity.

Have you looked at Wren? Being embeddable is a primary use case.

I make DOME Engine (https://domeengine.com) which lets you program using the Wren scripting language (https://wren.io)

Luxe uses the Wren scripting language, and has its own APIs on top of that. It also has a graphical editor, and a modular design where people can create modules which you can include in your project to extend the engine's capabilities.

Take a look at Wren by Bob Nystrom, who also wrote the book Game programming Patterns

I was initially going to do these in Python (and I still am) but someone in Discord got me to give Wren (https://wren.io/) a try. Here's my solution for both parts: import "io" for File

And as a follow-up to this, the wonderful Wren, which has some neat extensions to the work done in Crafting Interpreters.

I'd probably check out wren for just a generally better implementation as mine is essentially based on it's https://github.com/wren-lang/wren/blob/main/src/vm/wren_value.h.