[Completion] Support for triggers chars

[angelozerr]

Use ServerCapabilities#getCompletionProvider#getCompletionOptions#getTriggerCharacters to initialize completion processor to support triggers chars.

[mickaelistria]

+1. However it may also require some code to adopt triggerChars this in the Generic Editor as well.

[mickaelistria]

This depends on https://bugs.eclipse.org/bugs/show_bug.cgi?id=505632

[mickaelistria]

And a good integration also requires https://bugs.eclipse.org/bugs/show_bug.cgi?id=505635

[mickaelistria]

@angelozerr I pushed a change that should support it. However, I didn't manage to find a working language server that uses it. Do you have an example to suggest? If not, I'll probably just close this issue.

[kaloyan-raev]

@mickaelistria Try the JSON language server: https://github.com/Microsoft/vscode/blob/c67ef57cda90b5f28499646f7cc94e8dcc5b0586/extensions/json/server/src/jsonServerMain.ts#L64

[mickaelistria]

I'd like to, but there's TypeFox/ls-api#63 blocking good integration of JSON server.

[mniewrzal]

Autoactivation works ok but only after first manual activation (ctrl+space). Before that LSPDocumentInfo isn't computed for LSContentAssistProcessor.

[mickaelistria]

Moved to https://bugs.eclipse.org/bugs/show_bug.cgi?id=508463