Language data not being recognized on custom Language

v6
1

I have a custom language that I’m adding CodeMirror support for. I’ve subclassed Parser and am providing my own Parser (called ParserAdapter); I’m trying to add support for comments to my language:

const parserAdapter = new ParserAdapter();
const facet = defineLanguageFacet({
  commentTokens: { block: { open: "/*", close: "*/" } },
});

const language = new Language(facet, parserAdapter, []);

export const myLang = new LanguageSupport(language, [syntaxHighlight]);

I have been trying a variety of approaches but no matter what I seem to do, I can’t seem to get comment toggling via the default keymap working. Is my approach for defining language data incorrect?

(you can see the whole source here)

2

Does state.languageDataAt("commentTokens", 0) return anything in an editor with this language? Also, have you verified that your dependency tree is deduplicated and isn’t loading any library package twice?

3

When I log out state.languageDataAt("commentTokens", 0), it shows that it’s an empty array.

As far as the dependency duplcation–I had 6.6.0 and 6.0.0 referenced in various parts of my yarn.lock file. I downgraded the 6.6.0 to 6.0.0 (so now I only see 6.0.0 for the language package), but I still see the same output. From what I can tell, I only have a single version of the language package installed (there is only a single entry in my yarn.lock file and in my node_modules folder).

Should I be managing dependencies in a particular way with codemirror packges? Do I need to provide custom resolutions or anything like that?

4

When you clear your package lock and fully recreate it, npm is pretty good about deduplicating the whole tree and installing up-to-date packages. Any other operation that upgrades packages seems to risk creating weird duplications.

5

When you clear your package lock and fully recreate it, npm is pretty good about deduplicating the whole tree and installing up-to-date packages

Got it–I took the step of removing my lock file and recreating it, still seeing any empty array for state.languageDataAt("commentTokens", 0).

6

On closer look, it looks you’re not using languageDataProp to associate the language facet with your top node type, since that code never feeds that back to the parser.

7

Interesting–I saw that in the docs when trying to solve this but I wasn’t sure how to use that. Is this something I should be doing as an extension of creating my NodeSet (via NodeProp.add)? I had originally assumed that passing the facet in to Language() would attach the facet to the top node for me, but it appears that I need to do that myself?

8

Yes, you do need to do that (since a Language doesn’t know how to change a Parser). Passing in the prop, either with add or as a two-element array holding the node prop and the facet, when creating the node type should help.

9

Got it–I was able to get this working with the following code:

const topNode = NodeType.define({
  id: 0,
  name: "topNode",
  top: true,
  props: [
    [
      languageDataProp,
      defineLanguageFacet({
        commentTokens: { block: { open: "/*", close: "*/" }, line: "//" },
      }),
    ],
  ],
});

Thank you for your help!