Introduction to the Pattern Action language
You use the Pattern Action language to manipulate data. You can decipher and identify patterns in data, and then perform actions against the data based on the pattern.
A Pattern-Action file contains a series of pattern action sets. Each set contains a pattern condition followed by action statements. Actions are taken against input data that has been separated into tokens and classified. Actions are based on a given pattern of tokens.
- Operands
- Class representation of the incoming data. The class representation is either a user-defined class or a default class.
- User variables
- Defined by the user, symbolic names associated with values that can be changed.
- Dictionary fields
- A collection of output field names as defined in the dictionary table located in the dictionary definition file (.DCT).
Patterns are executed in the order they appear in the Pattern-Action file. A pattern either matches the input data or it does not match. If it matches, the actions associated with the pattern are executed. If not, the actions are skipped. Processing then continues with the next pattern in the file.
The pattern action file enables you to use logic which becomes a part of rule sets. Rule sets, applied against parsed and classified input data, standardize the data.
Pattern-Actions files are ASCII files that you can create or update by using any standard text editor.