Support visual selection for code actions

[slonoed]

Hello! And thank you for this excellent plugin.

I'm working on my language server and use this plugin in Vim 8. And I can't implement support for code actions, which requires some selection. Example: extract code to function.
This plugin always sends the cursor position for start and cursor + 1 column for end.
It would be nice, that if vim in selection mode it sends proper range.

I don't know viml. I tried to change this code

vim-lsc/autoload/lsc/params.vim

Line 14 in c6d088d

\ 'start': {'line': line('.') - 1, 'character': col('.') - 1},

by using line('v').
But end position with line('.') is wrong.

Reference in docs. http://vimdoc.sourceforge.net/htmldoc/eval.html#line()

I would like to help with this, but don't know where to start.

[natebosch]

I think the tricky part is knowing when to check "'<" vs '.' - we want to know if we were in visual mode when running the command and I'm not sure that we can know that...

[natebosch]

We could maybe do something like #179 but it's pretty hacky.

Alternatively we could add vnoremap key mappings which call the function in a way that specifies it was from visual mode, but then that would rule out the workflow of making a visual selection and typing the :LSClientFindCodeActions workflow. Getting that behavior worked into the configuration for keybindings is also tricky...

[slonoed]

I tried visual-range branch. It works when I run :'<,'>LSClientFindCodeActions. 👍
For visual I made this mapping

vnoremap <silent> ga :call lsc#edit#findCodeActions(lsc#edit#filterActions(), 0, 0)<CR>

Looks ugly, but works.