Provide trigger character hint to company-mode

[tigersoldier]

If the server provides trigger characters and the point is after one of them,
set :company-prefix-length to t so that company-capf always shows completion
candidates regardless the actual length of the prefix (which is likely to be 0).

[bkchr]

Works for me :)

@vibhavp anything against merging? :)

[vibhavp]

No issues as such, but this ends up adding a soft dependency on company-mode, right?

[bkchr]

You mean that it only works with company? Yeah you are probably right. Maybe the annotation could be made configurable

[tigersoldier]

@vibhavp It does provide company-only feature, since trigger character doesn't make sense to completion-at-point.

@bkchr I'm on the fence whether to add a custom variable to toggle it. It doesn't take much time to get the trigger characters. IMO it's not a good experience to have a long list of customizable settings for every tiny details.

[bkchr]

@tigersoldier I came across your https://github.com/tigersoldier/company-lsp project. I think, if that supports the trigger characters for company, it is okay to not merge the feature into lsp-mode directly.
While looking over your code, I saw that some functionality like:
(advice-add 'lsp--parser-on-message :after 'company-lsp--on-message)
Could be integrated into lsp-mode by providing a hook instead of hacking into the process.

[sebastiencs]

While looking over your code, I saw that some functionality like:
(advice-add 'lsp--parser-on-message :after 'company-lsp--on-message)
Could be integrated into lsp-mode by providing a hook instead of hacking into the process.

@bkchr My fault, I've wrote that functionality.
I didn't know the code of lsp-mode enough to make a PR to support async.
But it seems that there is now a PR for this purpose: #138

[bkchr]

@sebastiencs yeah no problem! :) Just thought loud about how the projects could be working together :)

[tigersoldier]

@bkchr I agree both projects can work better together and would love to push features upstream. Just wanted to get the feature landed quickly so I can use it :)

Back to the topic of this PR. My original plan was to implement all company-related feature here and just deprecate company-lsp in favor of company-capf. Now company-lsp is implementing some features that are hard to port to completion-at-point-function (e.g async completion, post-completion actions), the original goal is no longer feasible.

Let's close this PR.

[vibhavp]

@tigersoldier I've added support for async requests in b56a06e. If that helps, company-lsp should use it instead of advising internal functions.

[tigersoldier]

Sure, I'll update it.