4038: Group generated ast boilerplate apart from the interesting part r=matklad a=Veetaha
Boilerplate `AstNode` and `From` impls are moved to the end further from the interesting part in `generated.rs`
Co-authored-by: veetaha <veetaha2@gmail.com>
The fix is admittedly quit literally just papering over.
Long-term, I see two more principled approaches:
* we switch to a fully tree-based impl, without parse . to_string
step; with this approach, there shouldn't be any panics. The results
might be nonsensical, but so was the original input.
* we preserve the invariant that re-parsing constructed node is an
identity, and make all the `make_xxx` method return an `Option`.
closes#4044
todo!() "Indicates unfinished code" (https://doc.rust-lang.org/std/macro.todo.html)
Rust documentation provides further clarification:
> The difference between unimplemented! and todo! is that while todo!
> conveys an intent of implementing the functionality later and the
> message is "not yet implemented", unimplemented! makes no such claims.
todo!() seems more appropriate for assists that insert missing impls.
- Adds a new AstElement trait that is implemented by all generated
node, token and enum structs
- Overhauls the code generators to code-generate all tokens, and
also enhances enums to support including tokens, node, and nested
enums
The sytax tree output files now use .rast extension
(rust-analyzer syntax tree or rust abstract syntax tree
(whatever)).
This format has a editors/code/ra_syntax_tree.tmGrammar.json declaration
that supplies nice syntax highlighting for .rast files.
We treat macro calls as expressions (there's appropriate Into impl),
which causes problem if there's expresison and non-expression macro in
the same node (like in the match arm).
We fix this problem by nesting macor patterns into another node (the
same way we nest path into PathExpr or PathPat). Ideally, we probably
should add a similar nesting for macro expressions, but that needs
some careful thinking about macros in blocks: `{ am_i_expression!() }`.
