Epsilon Generation Language

EGL is a template-based model-to-text language for generating code, documentation and other textual artefacts from models. EGL supports content-destination decoupling, protected regions for mixing generated with hand-written code, and template coordination

• Decouple content from destination (can be used to generate text to files, to the clipboard, or as a server-side scripting language etc.)
• Call templates (with parameters) from other templates
• Define and call sub-templates
• Mix generated with hand-written code

• 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

• Tutorial: Using EGL as a server-side scripting language in Tomcat
• Example: Generate HTML from an Ecore metamodel
• Screencast: Generating an HTML report (part 1, part 2)

Chapter 7 of the Epsilon book provides a complete reference of the syntax and semantics of EGL.