Add Code Folding Support

[xanderdunn]

I just installed swift.vim in neovim 0.4.3. My swift files compile and run fine in Swift version 5.3-dev (LLVM 55d27a5828, Swift 6a5d84ec08).

But vim doesn't find any folds in my swift files. When I press one of the commands to open or close folds, such as zO or zc, I see the error E490: No fold found. This is unusual. Most languages have code folding support in vim.

[keith]

What is required to make this work?

[xanderdunn]

This swift plugin for vim, which hasn't been updated since 2015, indicates that it supports code folding. I haven't created a language plugin for vim before, I'm looking through it to see where the folding support comes in. I can't imagine it would be much different from C++ code folding, but I'm also new to Swift.

• It looks like this is the declaration that the plugin supports code folding
• My best guess is that the fold keywords peppered throughout this file indicate to Swift what to start and end folds on.
• Here is the documentation on the option to disable code folding.

[keith]

Happy to accept PRs for this but I likely won't get to it