2.5. Key Path

A key path is a string or list of strings that defines how to extract a key from a value. A valid key path is one of:

• An empty string.

• An identifier, which is a string matching the IdentifierName production from the ECMAScript Language Specification [ECMA-262].

• A string consisting of two or more identifiers separated by periods (U+002E FULL STOP).

• A non-empty list containing only strings conforming to the above requirements.

Spaces are not allowed within a key path.

Key path values can only be accessed from properties explicitly copied by StructuredSerializeForStorage, as well as the following type-specific properties: