tree-sitter creates parsers, e.g. for programming languages, config formats, etc.
Emacs modes can use those parsers on buffer contents, e.g. for syntax colouring/highlighting, finding matching delimiters (e.g. moving the cursor over an `if`, and having all the corresponding clauses (e.g. else/elif/fi) highlighted), for contextual editing (e.g. escaping " when inside a string), etc.
This can be remarkably tricky to get right; e.g. consider languages which can splice expressions inside strings (which can themselves contain strings, containing spliced expressions, etc.)
Using tree-sitter should make this easier and more robust (i.e. less time spent implementing parsers; more time spent implementing features!). I think it would also allow grammars to be re-used across different tools, which should improve support for obscure/niche languages.
Does this mean that every emacs language package would automatically make use of this once it is built in. Or will this rather enable the possibility to write/rewrite programming language modes so they make use of tree-sitter because they can assume it is available in the default emacs install from then on?
