Data Transformation Engine Type Designer Reference Guide

Chapter 13 - Distinguishable Objects A Group's Unbound Set
range of (1:1) is required. All the types of the components up to and including
CustomerID Record are part of the starting set for File ROOT. The starting set
of File ROOT is Statistics Record, Comment Record, and CustomerID
Record.
A Group's Unbound Set
Based on the nature of a bound group, the end of a bound group is determined
without analyzing the data that follows it. However, if a group is not bound, the
data that belongs to that group must be distinguishable from data that belongs to
another type that might follow it in the data stream.
The unbound set of a choice or unordered group consists of the type of each
component. The unbound set of a partitioned group consists of the unbound set of
each unbound partition.
Unbound Set of a Sequence Group
The unbound set does not include a type that could come last, if that type is a
required occurrence. For example, if the type Comment Record could appear last
and the component is specified as Comment Record (2:2), it is not in the
unbound set, because the two occurrences of Comment Record are required.
However, if Comment Record could appear last and the component is specified
as Comment Record (1:2), then Comment Record is in the unbound set, since
its second occurrence is optional.
To determine the unbound set of a group, start with the last component of the
group and proceed backward up the component list. If a component is unbound or
has a minimum range of zero, continue up the list. Stop at the first component
that is bound or that is unbound but has a minimum range greater than zero.
Essentially, a group’s unbound set is everything that is not clearly defined at the
end of the group.
In this example, Legacy File is an unbound group with the following components:
Legacy File is unbound because: