%w/%W/%i/%I children should be strings/symbols

[robrix]

Ruby’s %w/%W, and %i/%I syntaxes are array literals containing strings and symbols respectively. However, the parse tree won’t contain nodes with the appropriate names, even with the changes described in tree-sitter/tree-sitter#29.

I would like this source:

%w(hello world)

to end up with this parse tree:

(program (expression.literal.array (expression.literal.string) (expression.literal.string)))

However, note that the elements of the array would not be parsed via the string production; they’d be parsed via the array and named string sort of by fiat.

@maxbrunsfeld: Is there any way to assign names like that? API like this might do it:

rules: {
  array: choice(
    seq('[', commaSep($.expression), ']'),
    seq('%w(', sep({ string: /[^\s]+/ }, /\s+/), ')'),
    …
  ),
  …
}

Motivated by #4.

[maxbrunsfeld]

I think that having some way of naming pieces of a rule would be cool. I think in the meantime though, you could just do something like:

array: $ => choice(
  // ...
  seq('%w(', sep($.bare_string, /\s+/), ')')
),

bare_string: $ => (/[^\s]+/),

So that you get this parse tree:

(program (expression.literal.array (bare_string) (bare_string)))

That way, at least you get a node for each string in the array. They're semantically strings, but syntactically a different construct, so I think it is at least somewhat reasonable for them to appear differently in the parse tree.

[maxbrunsfeld]

I was just testing with ripper, to see how ruby's own parser treats this.

> Ripper.sexp "['one']"
=> [:program, [[:array, [[:string_literal, [:string_content, [:@tstring_content, "one", [1, 2]]]]]]]]

> Ripper.sexp "%w(one)"
=> [:program, [[:array, [[:@tstring_content, "one", [1, 3]]]]]]

It represents the %w strings as 'string content' nodes 😕. Makes sense, I guess.

[robrix]

Oh, interesting find—thanks for looking into that!