Is it possible to implement matching XML start/end tag names without an external scanner?

[s1341]

Hi,

I'm interested in writing a rule to generate an XML element, with matching start and end tag names.

Something like:

    element: $ => {
      var n = $.Name;
      return choice(
        $.EmptyElemTag,
        seq(
          seq(
            '<',
            n,
            c.rseq($._S, $.Attribute),
            O($._S),
            '>'
          ), O($.content),
          seq(
            '</',
            n,
            O($._S),
            '>'
          )
        )
      )
    },

But I'd like n to be instantiated once for the rule. I.e. to run the $.Name rule once. Is there a way to do this in tree-sitter?

[amaanq]

To answer your question directly, no, there is no way to do so without an external scanner, that requires being context aware. However, have you seen https://github.com/tree-sitter-grammars/tree-sitter-xml? It's implemented there, but did require the usage of an external scanner.

[s1341]

I did see it, which is why I was asking if there is a way to do it without an external scanner ;)

[amaanq]

yeah nah sadly, it'd be really hard to represent in the dsl and in the parser