@rcs-lang/language-service

Advanced language service implementation for RCL (Rich Communication Language) providing IDE features like code completion, diagnostics, hover information, and more.

Overview

This package implements a comprehensive language service that powers the RCL VSCode extension and can be integrated into other editors. It provides intelligent code editing features through the Language Server Protocol (LSP).

Features

• 🔍 Go to Definition - Navigate to symbol definitions
• 📝 Code Completion - Context-aware suggestions
• 🔎 Find References - Locate all usages of symbols
• 💡 Hover Information - Rich tooltips with documentation
• ⚠️ Diagnostics - Real-time error and warning detection
• 🔄 Rename - Safe symbol renaming across files
• 📑 Document Symbols - Outline view support
• 🎨 Semantic Highlighting - Enhanced syntax coloring

Installation

npm install @rcs-lang/language-service

Usage

Creating a Language Service

import { LanguageService } from '@rcs-lang/language-service';

const service = new LanguageService();

// Initialize with workspace
await service.initialize({
  workspaceFolders: ['/path/to/workspace']
});

Code Completion

const completions = await service.getCompletions({
  uri: 'file:///example.rcl',
  position: { line: 10, character: 15 }
});

// Returns context-aware suggestions
completions.items.forEach(item => {
  console.log(item.label, item.kind, item.detail);
});

Diagnostics

const diagnostics = await service.getDiagnostics('file:///example.rcl');

diagnostics.forEach(diagnostic => {
  console.log(
    `${diagnostic.severity}: ${diagnostic.message} at line ${diagnostic.range.start.line}`
  );
});

Go to Definition

const definition = await service.getDefinition({
  uri: 'file:///example.rcl',
  position: { line: 5, character: 10 }
});

if (definition) {
  console.log(`Definition found at ${definition.uri}`);
}

Architecture

The language service is built on several key components:

RclProgram

Central coordinator that manages the compilation state and provides unified access to language features.

WorkspaceIndex

Maintains an index of all symbols across the workspace for fast lookups and cross-file references.

Providers

Modular providers implement specific language features:

• CompletionProvider - Code completion logic
• DefinitionProvider - Go to definition functionality
• HoverProvider - Hover tooltip content
• ReferencesProvider - Find all references
• RenameProvider - Symbol renaming

Validators

• SemanticValidator - Type checking and semantic analysis
• ImportResolver - Module resolution and validation

Integration

VSCode Extension

The language service is designed to work seamlessly with the VSCode Language Server Protocol:

import { 
  createConnection,
  TextDocuments,
  ProposedFeatures
} from 'vscode-languageserver/node';

const connection = createConnection(ProposedFeatures.all);
const documents = new TextDocuments(TextDocument);
const service = new LanguageService();

connection.onCompletion(async (params) => {
  return service.getCompletions(params);
});

connection.onDefinition(async (params) => {
  return service.getDefinition(params);
});

Custom Editor Integration

For other editors, implement the language service API directly:

class MyEditorPlugin {
  private service: LanguageService;

  constructor() {
    this.service = new LanguageService();
  }

  async onCursorMove(file: string, line: number, col: number) {
    const hover = await this.service.getHover({
      uri: `file://${file}`,
      position: { line, character: col }
    });
    
    if (hover) {
      this.showTooltip(hover.contents);
    }
  }
}

Configuration

The language service supports various configuration options:

interface LanguageServiceConfig {
  // Enable/disable specific features
  features?: {
    completion?: boolean;
    hover?: boolean;
    definition?: boolean;
    references?: boolean;
    rename?: boolean;
    diagnostics?: boolean;
  };
  
  // Validation settings
  validation?: {
    syntaxErrors?: boolean;
    semanticErrors?: boolean;
    styleWarnings?: boolean;
  };
  
  // Performance tuning
  indexing?: {
    maxFileSize?: number;
    excludePatterns?: string[];
  };
}

Contributing

See the main repository README for contribution guidelines.

License

MIT