Parsing non-octal leading-zero numeric strings with YAML 1.1 directive should be strings

[grzm]

In YAML 1.1, numeric scalars with leading zeros that include characters 8 or 9 do not need to be quoted. For example, the scalar 083 must be a string as it can't be a valid octal value. In YAML 1.2, 083 is interpreted as a number.

My understanding is that a YAML directive in a YAML document should allow a YAML processor to distinguish between these specifications. For example, given the following document:

%YAML 1.1
--- 083

The yaml processor should know to interpret the scalar 083 as the string "083" instead of as the number 83. js-yaml interprets the value as the number 83. Here's an example package.json and index.js

{
  "dependencies": {
    "js-yaml": "^4.1.0"
  }
}

const yaml = require('js-yaml');

const unquoted = "%YAML 1.1\n--- 083\n";
const quoted = "%YAML 1.1\n--- '083'\n";

const vals = [unquoted, quoted];
for (const val of vals) {
    console.log(">>>START<<<");
    console.log(val);
    console.log(">>>END<<<");
    console.log(yaml.load(val));
}

% node index.js
>>>START<<<
%YAML 1.1
--- 083

>>>END<<<
83
>>>START<<<
%YAML 1.1
--- '083'

>>>END<<<
083

I'd expect both of these to parse as the string "083" given the %YAML 1.1 directive.