Data Transformation Engine Type Designer Reference Guide

Chapter 7 - Group Properties Group Subclass
Type syntax properties such as Initiator, Terminator, Release, and Empty may
be applied to Choice groups. If a release character is defined, by default it applies
to the Terminator.
Choice Group Components
The components of a choice group are similar to the partitions of a partitioned
type. However, a Choice group can have both items and groups as components. A
partitioned Sequence group can only have group subtypes.
Components of a Choice group must be distinguishable from each other. The
components of a Choice group cannot have a component range other than (1:1).
Only one component of a Choice group built in the output data.
A Choice group data type is only one of the group components. For example, the
data type Record is a group type with a Group Subclass of Choice. The group
type Record has three components: Order, Invoice, and Sales. The data
validation of Record will be only one of the components: Order, Invoice, or
Sales. For this reason, the components of a Choice group must have a component
range of (1:1).
Unordered Group Components
An unordered group has one or more components that can appear in the data
stream in ay order. They allow many SWIFT and FIX message types, for
example, to be defined in a more natural way.
Unordered groups have no partitioned property. They have Implicit format
properties with the same syntax options as sequence groups: None and
Delimited.
When a group is defined as Unordered, any component can appear in the data
stream. A component can be an item or a group.
Unordered group components have a range property. For example, if the
unordered group, A, has the following component list:
B(1:S)
C
D(S)
then A must have one C, at least one B, and possibly some Ds. They could appear
in any order. For example, data for
A could have the pattern: CDDBDDD or
BBBDDCBD.
Component rules of an unordered group cannot reference other components of the
same group. They can only reference the component to which the rule refers and
the objects contained in that component.