Optional extent of the analysis area (where the focal operation will be executed)
(focalCalculation: StringAdd).self
(focalCalculation: StringFormat).self
(focalCalculation: ArrowAssoc[FocalCalculation[T]]).x
(Since version 2.10.0) Use leftOfArrow
instead
(focalCalculation: Ensuring[FocalCalculation[T]]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
A calculation that a FocalStrategy uses to complete a focal operation.