OPAL Semistructured Verbs

Semistructured verbs act upon, or produce, arrays or objects that are treated as scalars. E.g., a single column may contain multiple values in an array, or multiple key/value tuples in an object.

The values inside semi-structured containers are stored as variants, and must be cast to the type you expect them to have. If the array or object contains a value of an unexpected type, the cast returns null.

Verb	Description
extract_regex	Add one or more columns by matching capture names in a regular expression against a given source expression.
flatten	Given an object or array input, recursively flatten all child elements into key-value columns, with null intermediates.
flatten_all	Given an object or array input, recursively flatten all child and intermediate elements into key-value columns.
flatten_leaves	Given an object or array input, recursively flatten all child elements into key-value columns, returning only leaf values.
flatten_single	Given an object or array input, flatten the first level of child elements into key-value columns.