Language workbenches: https://www.martinfowler.com/articles/languageWorkbench.html
Nice intro to structural editing:https://firstname.lastname@example.org/looking-at-code-th... (also mentions scratch)
The basic idea has been around for a while.
Here's something from the 80's: Alice Pascal https://www.templetons.com/brad/alice.html
> One of the first projects I did after forming Looking Glass Software Limited was a syntax-directed programming environment called Alice: The Personal Pascal.
> Syntax-directed editors are somewhat controversial, however I think they are quite good for people learning programming, and Alice was written first to be used in education in the school systems of Ontario. Our first sale was a contract to develop it for the Ministry of Education there.