* VM: Implement LetDeclList and the `let` keyword
* Support var and const
* Split defining and initializing into separate instructions
* DefLet doesn't need the value
* InitLexical initializes value if set
* Code review
* Fix rustfmt
* Add documentation
* InitLexical fix
Co-authored-by: jasonwilliams <jase.williams@gmail.com>
Nodes implement CodeGen which generates instructions onto a stack held in Context.
The VM will interpret the instructions from Context.
There are some issues:
- Only basic instructions are added, but I'm working off https://developer.mozilla.org/en-US/docs/Mozilla/Projects/SpiderMonkey/Internals/Bytecode for now it should be easy to add more in.
- The Stack is a Vec, this isn't ideal (we may be able to live with it for now) but the stack should really be a fixed sized array. This isn't possible because Value can't be copied in there as it holds Rc and Gc values. Can we have fixed-sized Values that hold a pointer? Something like the "stackvec" crate should help
- put all VM related code behind "vm" feature flag
Co-authored-by: Jason Williams <jwilliams720@bloomberg.net>
Co-authored-by: Halid Odat <halidodat@gmail.com>
Jason Williams
Annika