@domainlang/language


Core language library for DomainLang - a Domain-Driven Design modeling language built with Langium.

Features

- 🔤 Parser - Full DomainLang grammar with error recovery
- ✅ Validation - Semantic validation for DDD best practices
- 🔗 Linking - Cross-reference resolution across files and packages
- 🔍 Model Query SDK - Programmatic access to DDD models with fluent queries
- 🌐 Browser Support - Works in Node.js and browser environments

Installation

``bash
npm install @domainlang/language
`

Quick start

$3

`typescript
import { loadModelFromText } from '@domainlang/language/sdk';

const { query } = await loadModelFromText(
Domain Sales {
vision: "Enable seamless commerce"
}

bc OrderContext for Sales as Core by SalesTeam {
description: "Handles order lifecycle"
}
);

// Query bounded contexts
const coreContexts = query.boundedContexts()
.withClassification('Core')
.toArray();

console.log(coreContexts[0].name); // 'OrderContext'
`

$3

`typescript
import { loadModel } from '@domainlang/language/sdk/loader-node';

const { model, query } = await loadModel('./my-model.dlang');

// Access domains
for (const domain of query.domains()) {
console.log(${domain.name}: ${domain.vision});
}
`

API overview

$3

| Function | Environment | Use Case |
| -------- | ----------- | -------- |
| loadModelFromText(text) | Browser & Node | Parse inline DSL text |
| loadModel(file) | Node.js only | Load from file system |
| fromDocument(doc) | LSP integration | Zero-copy from Langium document |
| fromModel(model) | Advanced | Direct AST wrapping |

$3

The SDK provides fluent query builders with lazy evaluation:

`typescript
// Find all bounded contexts owned by a team
const teamContexts = query.boundedContexts()
.withTeam('PaymentsTeam')
.toArray();

// Get context maps containing specific contexts
const maps = query.contextMaps()
.containing('OrderContext')
.toArray();
`

$3

`typescript
// Direct AST properties
const desc = boundedContext.description;
const vision = domain.vision;

// SDK-augmented properties (with precedence resolution)
const classification = boundedContext.effectiveClassification; // Header 'as' wins over body 'classification:'
const team = boundedContext.effectiveTeam; // Header 'by' wins over body 'team:'
`

DomainLang syntax

DomainLang models Domain-Driven Design concepts:

`dlang
// Define domains with vision
Domain Sales {
vision: "Drive revenue through great customer experience"
}

// Bounded contexts with ownership
bc OrderContext for Sales as Core by SalesTeam {
description: "Order lifecycle management"
}

bc PaymentContext for Sales as Supporting by PaymentsTeam

// Context maps showing integrations
ContextMap SalesIntegration {
contains OrderContext, PaymentContext

[OHS,PL] OrderContext -> [CF] PaymentContext
}
`

Package structure

| Path | Purpose |
| ---- | ------- |
| src/domain-lang.langium | Grammar definition |
| src/generated/ | Auto-generated AST (do not edit) |
| src/validation/ | Semantic validation rules |
| src/lsp/ | LSP features (hover, completion, formatting) |
| src/sdk/ | Model Query SDK |

Related packages

- @domainlang/cli - Command-line interface
- DomainLang VS Code Extension - IDE support

Documentation

- Getting Started
- Language Reference
- Quick Reference
- SDK Documentation

Development

From the workspace root (dsl/domain-lang/):

`bash


After editing the grammar

npm run langium:generate

Build this package

npm run build --workspace packages/language

Run tests

npm test --workspace packages/language
``

License

Apache-2.0