MTLModule

struct MTLModule

Overview

An MTL module is the root container for a text generation specification, containing source metamodels, templates, queries, macros, and module-level configuration. MTL modules define transformations from models to text using declarative templates and imperative control structures.

Overview

MTL modules follow a structured approach to model-to-text transformation:

• Metamodels: Reference metamodels that define the structure of input models

• Templates: Text generation units with parameters and control flow

• Queries: Side-effect-free operations for computed values

• Macros: Language extensions for pattern reuse

• Module hierarchy: Inheritance and imports for modular organization

Module Inheritance

MTL supports module inheritance through the extends mechanism, allowing templates to be specialized and overridden in module hierarchies:

// Base module
let baseModule = MTLModule(
    name: "BaseGen",
    metamodels: ["Model": modelPackage],
    templates: ["generate": baseTemplate]
)

// Derived module (overrides base template)
let derivedModule = MTLModule(
    name: "DerivedGen",
    metamodels: ["Model": modelPackage],
    extends: "BaseGen",
    templates: ["generate": overridingTemplate]
)

Example Usage

let module = MTLModule(
    name: "ClassGenerator",
    metamodels: ["UML": umlPackage],
    templates: ["generateClass": classTemplate],
    queries: ["isPublic": isPublicQuery],
    macros: ["repeat": repeatMacro],
    encoding: "UTF-8"
)