Distinguish between null and undefined with parse()

[gee4vee]

Is there a way I can configure parse so that I can distinguish between a value not having a value and having null as the value? As it stands, in either case I get null as the value.

[eemeli]

With the default schema (YAML 1.2 core), an empty string and null are both representations of a null value.

If you use the parseDocument API, the parsed node's source does provide this info:

YAML.parseDocument('null').contents

Scalar {
  value: null,
  range: [ 0, 4, 4 ],
  source: 'null',
  type: 'PLAIN'
}

[gee4vee]

So I'm looking at the parsed document contents but seeing null as the value for a yaml that has nothing (not empty string). I'm looking to distinguish no value (not empty string) and null.

[gee4vee]

I suppose I have to look at the source, type, and value to determine if it's empty string, nothing, or null.