feat: allow rules to be treesitter context aware (#423)

[kamalsacranie]

When a rule is defined which calls the :with_context() method, has a
specified filetype, and is operating in a buffer with a treesitter
parser attached, the rule will only execute iff the treesitter language
at the cursor matches one of the filetypes specified in the initial rule
definition.

If there are no specified filetypes, of there is no parser attached to
the current buffer, the rule executes as normal

---

For the tests, I created a sample.md file which I then use with the rule to test. It was required to make a small modification to Test_withfile. We needed to carry out a full parse of the buffer tree which returns a language tree with the injected child trees. The test check if the rules work exclusively in the specified grammars/filetypes.

[windwp]

Thank you for your PR.

I expect it can handle a different behavior of existing rule with inline file type
sample with rule f''' on python.

 ```python
  f''' # type it on python it will become f'''|'''
 ```

or rule <!-- --> . so it can only work on markdown and html

Yeah, I know it needs a lot of refactoring.

That's why I suggest using a conditional behavior. Your tree sitter context only of affecting one rule with the character *, so you only need to add a condition like this:

Rule('*', '*', { 'markdown' }):with_pair(ts_conds.is_not_inside_context())

[kamalsacranie]

Yours is a much cleaner implementation. I think would be good to have

Rule("*", "*"):with_pair(ts_conds.is_inside_context({"markdown"}))
Rule('f"""', '"""'):with_pair(ts_conds.is_inside_context({"python"}))

That way, we can have the behaviour you mentioned.

I expect it can handle a different behavior of existing rule with inline file type sample with rule f''' on python.

 ```python
  f''' # type it on python it will become f'''|'''
 ```

I think if we specify the filetype, the rule will not run when we are not in the filetype specified. I.e. if we did Rule(..., {"python"}), then the rule would not run in the markdown code block because we aren't in a python file (is this correct?). Let me know if you would prefer it to be like you mentioned before (Rule('*', '*', { 'markdown' }):with_pair(ts_conds.is_not_inside_context()))

[windwp]

but the problem is if we use condition then that rule will not load to buffer or create a mapping on buffer

if you change this pr to add a new condition. i will merge.
I will thinking about how to apply it to exisiting rules later.

[kamalsacranie]

Okay. I've implemented it how you suggested

[windwp]

ok, thank