Name anonymous types in api.h

[MatthewGentoo]

Anonymous structs cannot be forward declared. This change names anonymous types in api.h so that consumers can forward declare them.

[MatthewGentoo]

(I'm unsure why the test test_python_corpus is failing, I can try and rebase on master if it's fixed there)

[MatthewGentoo]

ping

[ahlinc]

@MatthewGentoo Could you explain what sense to have forward declarations for structs from the api.h file if the api.h file is protected by #ifndef TREE_SITTER_API_H_ and can be included many times in every place where it's needed?

[dundargoc]

What problem does this PR solve? I don't get it. I think the C code should work as is.

[MatthewGentoo]

Hi, sorry for the delayed response and lack of explanation.

In C and C++, anonymous types can't be forward declared. Forward declaring the types allows for headers in the application to skip including tree_sitter/api.h. While the impact to compile time is quite small (some libraries, especially C++ ones, are a lot worse...) every little helps in larger applications.

[dundargoc]

Eh, I feel like the structs here are so small that I find it hard to believe it'd make much difference. That said, I don't see a problem with including this anyway since it's a non-intrusive change. Thanks for the explanation.