Define labeled items recursively

[nickcoutsos]

Hi again!

I'm at a point where I need to parse all of the labels for a node from the devicetree source but currently the additional node yields an error.

Examples

> parser.parse('foo: bar {};').rootNode.toString()
'(document (labeled_item label: (identifier) item: (node name: (identifier))))'
> parser.parse('foo: bar: baz {};').rootNode.toString()
'(document (labeled_item label: (identifier) (ERROR (identifier)) item: (node name: (identifier))))'

I'm sure my solution isn't suitable so this is partly a question of the intended difference between labeled_node and labeled_item and how the aliasing should work. Originally the only way I got the recursion working for arbitrarily many labels was to delete the labeled_node rule and make define labeled_item recursively.

Alternative approach:

Locally I've just tried another change where both rules are recursive versions of themselves:

labeled_node: ($) =>
    seq(
        field('label', $.label_identifier),
        ':',
        field('item', choice($.labeled_node, $.node))
    ),

labeled_item: ($) =>
    seq(
        field('label', $.label_identifier),
        ':',
        field('item', choice($.labeled_item, $.node, $.property))
    ),

This doesn't cause errors, but the results for the same test committed in this branch differ:

    (document
      (labeled_item
        label: (identifier)
        item: (labeled_node
          label: (identifier)
          item: (labeled_node
            label: (identifier)
            item: (labeled_node
              label: (identifier)
              item: (node
                name: (identifier)))))))

The three nested labels are picked up as labeled_node this time instead of labeled_item like the outermost. Is this because the aliasing of the rule only applies to top level items? I'm not sure what you would consider to be more appropriate.

[nickcoutsos]

@joelspadin I'm doing some more work with managing/editing labels and realized it makes more sense to treat multi-labeled nodes as a single labeled_item node with multiple label fields.

I've made a separate branch to show the relevant changes here: https://github.com/joelspadin/tree-sitter-devicetree/compare/main...nickcoutsos:tree-sitter-devicetree:feature/multi-labeled-nodes-alternate

[joelspadin]

Thanks!

[nickcoutsos]

Hi Joel!

Did you have any thoughts on the two approaches? I feel like multiple label fields in a single labeled_item node makes more sense, and it's the approach I'm using now, but I neglected to update this PR to propose that instead.

[joelspadin]

Oh, true. I do think that might make more sense.