I would love it if version control stored an AST that also includes comments and dividers (where right now we would leave an empty line) and dev machines rendered it out however they wanted. They could even change the language of keywords in addition to normal formatting.
To do this requires some standard way of encoding an AST which includes comments and dividers.
That standard format is commonly known as source code - although it lacks a normal form.
Tools like prettier, gofmt and black can be thought of as a way to produce a normal form of source code.
This is (IMO) a reasonable incremental approach towards exactly what you describe - if a project checks in only source code that's formatted using a standardised format, then you're free to work on it using whatever equivalent representation you like - as long as it's converted back at commit-time.
The challenge for a tool like difftastic is that I can't guarantee that syntax is well-formed. You might be using new syntax that my parser doesn't support, you might have merge conflicts, or you might have a plain syntax error in your code.
Tree-sitter handles parse errors gracefully, so difftastic handles syntax errors pretty well in my experience.
Yep, I posted this idea on Reddit recently and people said they need a formatted syntax because of diff and version control; we do not; get the ast, reformat in the editor as the particular user fancies and generate diff and version control artefacts also as a particular user sees fit. Our computers are very fast so you can make a lot more different views on your code than we have now by using the ast instead of text and regexps.
Well, the comment I was responding to was about storing the AST, not diffing it. If that's what you meant the one follows naturally from the other. Once the file format is the AST instead of its visual representation, it makes sense to implement lots of operations as DSL extensions instead of library features, because the language is the library in a sense. MPS is marketed as a DSL tool but what really is is a projectional language tool.
