Epsilon Transformation Language

ETL is a hybrid, rule-based model-to-model transformation language built on top of EOL.ETL provides all the standard features of a transformation language but also provides enhanced flexibility as it can transform many input to many output models,and can query/navigate/modify both source and target models.

• Transform many input to many output models
• Ability to query/navigate/modify both source and target models
• Declarative rules with imperative bodies
• Automated rule execution
• Lazy and greedy rules
• Multiple rule inheritance
• Guarded rules

• Support for simultaneously accessing/modifying many models of (potentially) different metamodels
• All the usual programming constructs (while and for loops, statement sequencing, variables etc.)
• Support for those convenient first-order logic OCL operations (select, reject, collect etc.)
• Ability to create and call methods of Java objects
• Support for dynamically attaching operations to existing meta-classes and types at runtime
• Support for cached operations
• Support for extended properties
• Support for user interaction
• Ability to create reusable libraries of operations and import them from different Epsilon (not only EOL) modules

• Transform a Tree model into a graph model with ETL
• Transform an OO model to a DB model with ETL

Chapter 6 of the Epsilon book provides a complete reference of the syntax and semantics of ETL.