Libraries: Revert changes that were necessitated by a new rule we have decided not to introduce.
Parser:
- Support mixed constructors/bindings in types.
- Disallow zero-length hex sequences in character escapes: `\x`, `\u`, `\u{}`, `\U`, `\U{}` are no longer legal synonyms for `\0` (matches old parser behavior).
This PR contains all work for finishing integration of first Component List Panel in the IDE:
* It adds a stub for the whole Component Browser View. The documentation panel is re-used from the old searcher.
* It has the presenter implementation, integrating the view with Hierarchical Component List from the controller.
* It extends the View API, so the integration is possible, making use of Component Group Set wrapper.
* The selection integration was also merged into this PR, because it depended on the API extension mentioned above. However, we should avoid such practice in the future.
https://user-images.githubusercontent.com/3919101/177816427-8c4285b4-8941-4048-a400-52f4acf77a9f.mp4
# Important Notes
There are some known issues, to-be-fixed in the future.
* The performance is bad. It should be improved with new text::Area, and the decent one shall come with [GridView inside component browser](https://www.pivotaltracker.com/story/show/182561072)
* There is no keyboard navigation. It should also be delivered with [GridView](https://www.pivotaltracker.com/story/show/182561072).
* The Favorites section is not [filtered out by node source type](https://www.pivotaltracker.com/story/show/182661634).
implement simple variable assignments and function definitions.
This implements:
- https://www.pivotaltracker.com/story/show/182497122
- https://www.pivotaltracker.com/story/show/182497144 (the code blocks are not created yet, but the function declaration is recognized.)
# Important Notes
- Introduced S-expression-based tests, and pretty-printing-roundtrip testing.
- Started writing tests for TypeDef based on the examples in the issue. None of them parse successfully.
- Fixed Number tokenizing.
- Moved most contents of parser's `main.rs` to `lib.rs` (fixes a warning).
