Parser for Vim9 Script

[sheerun]

Describe the solution you'd like

If vim source included parser for Vim9 Script (i.e. function that converts source to ast), it would be very useful for implementing highlighting and language servers for Vim9 Script. Currently if one wants to do so he/she needs to create Vim9 parser from scratch... and keep it up do date with changes in it

As far as I can tell from current source vim doesn't generate AST, and compiles code directly instead, yes? Could this be potentially changed to produce AST, maybe as byproduct?

[brammool]

I have considered making a tree representation before producing code. I estimate that it will add quite a bit of overhead and does not have much gain. Creating the tree nodes and later cleaning them up, instead of mostly using stack space, can easily consume a lot of time. The possible gain of producing more efficient code is likely small, unless a full optimizer is used, which is again quite time consuming.
It's still open to give this a try later. Or in a separate branch. I'm now concentrating on making everything work, which is already lots of work to do.

[sheerun]

Could tree be created as by-product instead? i.e. as an option

[sheerun]

What I mean is: let compiler create AST while parsing, but not use it in any way

[andymass]

Can a real grammar be written for vim9? In other words, is the vim9 language 'nicely specified' with low context-sensitivity?

[brammool]

Most likely not.