@ifc-lite/codegen

TypeScript code generator from IFC EXPRESS schemas.

Overview

This package parses official IFC EXPRESS schema files (.exp) from buildingSMART and generates:

• TypeScript entity interfaces with full inheritance
• Schema registry with type metadata
• Attribute definitions and type information
• Enum definitions

Why?

Instead of manually implementing 1000+ IFC entity types, we generate them automatically from the official schemas. This gives us:

• ✅ 100% schema coverage
• ✅ Automatic updates when schemas change
• ✅ Type-safe TypeScript
• ✅ Consistent with IFC standard

Usage

Generate code from schema

npm run generate:ifc4      # Generate from IFC4 schema
npm run generate:ifc4x3    # Generate from IFC4X3 schema

Programmatic usage

import { parseExpressSchema, generateTypeScript } from '@ifc-lite/codegen';

const schema = parseExpressSchema('./schemas/IFC4.exp');
const code = generateTypeScript(schema);

Architecture

IFC4.exp (EXPRESS schema)
    ↓
ExpressParser
    ↓
Schema AST (entities, types, enums)
    ↓
TypeScriptGenerator
    ↓
Generated files:
  - entities.ts (interfaces)
  - schema-registry.ts (metadata)
  - types.ts (enums, selects)

EXPRESS Schema Format

EXPRESS is a data modeling language defined in ISO 10303-11. Example:

ENTITY IfcWall
  SUBTYPE OF (IfcBuildingElement);
  PredefinedType : OPTIONAL IfcWallTypeEnum;
END_ENTITY;

Generated Output

export interface IfcWall extends IfcBuildingElement {
  PredefinedType?: IfcWallTypeEnum;
}

export const SCHEMA_REGISTRY = {
  IfcWall: {
    parent: 'IfcBuildingElement',
    attributes: [
      { name: 'PredefinedType', type: 'IfcWallTypeEnum', optional: true }
    ]
  }
};

Testing

The generator includes comprehensive tests:

• EXPRESS parser tests (tokenization, entity parsing, type parsing)
• TypeScript generator tests (interface generation, inheritance)
• Integration tests (generate from real schemas, validate output)

npm test

Integration with Parser

This package is standalone and does not depend on @ifc-lite/parser. Once the generated code is validated, it can be integrated into the parser package.

License

MIT