Data Transformation Engine Functions and Expressions Reference Guide

Chapter 1 - Expressions and Evaluations Evaluating Expressions
Functions and Expressions Reference Guide
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Using Ellipses
A single period can be used, like ellipses, in place of object names, as long as that
object name can be interpreted as a unique object.
For example, if you have the following object name:
City Field:BillTo Customer:Account:File
you may be able to replace it with
City Field:.:File
If file also contains another City Field, such as
City Field:ShipTo Customer:Account:File
and you use the Use Ellipses option, the system returns
City Field:BillTo Customer:.:File
Evaluating Expressions
Expressions are evaluated based on the context in which data object names,
literals, operators, function names and map names appear in the expression, and
the data on which it operates. A component rule always evaluates once for each
occurrence of a component. A map rule can evaluate many times.
When a map rule evaluates, the Map Designer selects an evaluation set of values
and then evaluates the rule. Then it selects another evaluation set of values, if
there is one, and evaluates the rule again. This continues until all the different
evaluation sets have been used.
The same number of evaluations is always produced, but output objects can be
ordered differently, depending on how you define your map.
For a selected evaluation set, a particular instance of a rule is evaluated using
parentheses, operator precedence rules, and left-to-right precedence rules to get
one result.
Card Order Can Influence the Order of Evaluation Sets
When an evaluation set is selected, card object names are ordered by their
position in the map: card 1 before card 2, and so on. The card order for a map can
affect the order of output results.