Questions regarding _hosts completion extension

["Mikhail f. Shiryaev" <mr.felixoid@xxxxxxxxx>]

Hello dear workers,

I have some questions regarding a stock _hosts completion function.

The original function, IMHO, has a few flaws that kind of difficult to address without a heavy development, in particular:

• It doesn't use cache features, so the shell instances don't share the state between them
• It fills up the _cache_hosts only once at the first completion, and the only way to refresh it is `unset _cache_hosts`. A bit obscured
• If one wants to extend the function with his values, then a way to go suggested on the Internet is defining a style `zstyle -e ':completion:*:hosts' hosts 'reply=(...)`. Unfortunately, it completely overrides the original function.
• If `reply` executes any function or binary under the hood, the terminal hangs after each <tab> pressing.
  

I've spent some time developing a solution addressing all mentioned points. It's the third implementation. The first one was done as an internal product, and the two last are in my repository https://github.com/Felixoid/zsh-hoco/blob/master/hoco.zsh. Features it has:

• Users can set HOCO_FUNCTIONS array. Then its output will be split by spaces, tabs, and new lines, and used as the hosts' completion.
  
• Uses the cache functions _store_cache, _retrieve_cache, and _cache_invalid. The cache content is shared between instances when `:completion:* use-cache` is set.
• Functions or binaries are executed in the background and don't block the terminal.
  

I'd like to ask about your opinion if it makes sense to bring it to the upstream. I am sure it still doesn't comply with the requirements for 100% and can be improved. On the other hand, it brings many advantages. I'd like to hear your opinion before trying to prepare a patch if it completely breaks some rules though. For example, if async shouldn't be used in completion.

What do you think?

Best regards,

Mikhail f. Shiryaev