Apply a single mapper to a value.
Either a transformation function (v: any) => any, or a string key referencing one of the MAPPERS built-ins (e.g. 'date_from_json').
(v: any) => any
'date_from_json'
The raw value to transform.
The transformed value.
If mapper is a string that does not exist in MAPPERS.
mapper
Apply a single mapper to a value.