ATLMatchedRule

struct ATLMatchedRule

Overview

Matched rules form the core of ATL’s declarative transformation approach. They are automatically executed for all source elements that match their input patterns and satisfy their optional guard conditions. Each matched rule transforms source elements into one or more target elements through pattern-based specifications.

Overview

Matched rules operate through several key components:

• Source pattern: Defines the input element type and optional variable binding

• Guard condition: Optional boolean expression for conditional rule execution

• Target patterns: Specify the output elements and their property bindings

• Implicit execution: Rules are triggered automatically by the ATL virtual machine

Example Usage

let member2MaleRule = ATLMatchedRule(
    name: "Member2Male",
    sourcePattern: ATLSourcePattern(
        variableName: "s",
        type: "Families!Member"
    ),
    targetPatterns: [
        ATLTargetPattern(
            variableName: "t",
            type: "Persons!Male",
            bindings: ["fullName": concatenationExpression]
        )
    ],
    guard: genderCheckExpression
)