Custom filters for suggestions

[rm-code]

The issue

I am currently writing my own provider, which should provide snippets and autocomplete functionality for functions of the LÖVE framework. The problem is, that autocomplete-plus uses the snippet field for filtering when filterSuggestions is set to true (at least as far as I can tell).

For example it wouldn't work for a suggestion like this:

  {
    "displayText": "love.directorydropped",
    "type": "function",
    "description": "Callback function triggered when a directory is dragged and dropped onto the window.",
    "descriptionMoreURL": "https://love2d.org/wiki/love.directorydropped",
    "snippet": "function love.directorydropped(${1:path (string)})\n    ${2:body (lua)}\nend\n"
  }

I'd like to type ldir and have the suggestion for love.directorydropped at the top of the autocomplete list, but since autocomplete-plus tries to match ldir to the snippet (which starts with function ... nothing is suggested at all.

This also means you can't use snippets which start with a variable:
${0:Source}:isPaused()

Suggestion

Of course this might just be a special case which rarely comes up, but maybe it might make sense to allow creators of new providers to specify a filter field which is matched against the prefix.

  {
    "displayText": "love.directorydropped",
    "type": "function",
    "description": "Callback function triggered when a directory is dragged and dropped onto the window.",
    "descriptionMoreURL": "https://love2d.org/wiki/love.directorydropped",
    "filter": "love.directorydropped",
    "snippet": "function love.directorydropped(${1:path (string)})\n    ${2:body (lua)}\nend\n"
  }

autocomplete-plus could still fall back to the default behaviour, if the filter field isn't provided.

[rm-code]

Updated the description with another case where this behavior causes troubles.

[rm-code]

This seems to have been added / fixed by now.