Add a way to include "extra settings"

[michaelpj]

When working on a new HLS feature, it is common to want to add some settings. Ideally, these eventually are exposed as proper settings in the extension, but when hacking on it it would be nice to have a way to toggle your new settings without having to edit the extension.

I suggest we could have something like an unstructured "extra-settings" bag, which will just get added in before sending to the server. I'm not sure whether there's an appropriate way to do this in vscode, though.

[July541]

If I remember correctly, while working on hls-class-plugin, I can add extra settings directly as normal settings in settings.json.

[fendor]

Right, but there is no general way to specify arguments that are sent to HLS directly.

The suggestion is basically to have a haskell.genericConfig field which takes a json object. These options are sent as part of the initialisation request.

For example, imagine hls-cabal-plugin has some config that we haven't specified in vscode-haskell

vscode-haskell/package.json

Line 214 in 5778bfb

"haskell.plugin.cabal.globalOn": {

. There is currently no way to specify any options the vscode extension doesn't know about, right?

[July541]

Sorry for confusing you, I mean I can(not entirely certain) add this to settings.json before the package.json has this field.

vscode-haskell/package.json

Line 238 in 5778bfb

"haskell.plugin.class.codeLensOn": {

[fendor]

Really? That's great, we should advertise it then :)