package orsetto

Use required k m to compose a group element that requires a value matching the model m to be indexed in the sequence with k.

Use optional k m to compose a group element that admits an optional value matching the model m if it is indexed in the sequence with k.

Use default k m v to compose a group element that admits an optional value matching the model m if it is indexed in the sequence with k, and if it is not present, then the scanner produces the default v for the element.