Translation unit filters are represented by the abstract FilterExpression class, which represents a boolean expression that works on translation units fields. There are two concrete classes that derive from this:

• AtomicExpression: A filter expression that compares a single translation unit field against a specified value using the specified operator.
• ComposedExpression: A filter expression that can be used to build complex filter expression from other filter expression, either by combining two filter expressions using the AND or NOT operator, or by negating a filter expression. Composed filter expressions can be nested.

The field values (FieldValue) that can be used in an atomic filter expression include:

• User-defined fields: See Working with Field Definitions.
• System fields: These are a number of built-in translation unit fields as defined in SystemFieldDefinitions.

Other Resources