@rcs-lang/ast

Parser-independent AST (Abstract Syntax Tree) type definitions for the RCL (Rich Communication Language).

Overview

This package provides TypeScript type definitions for the RCL Abstract Syntax Tree. It serves as a shared contract between the parser and compiler packages, ensuring type safety and consistency across the RCL toolchain.

Installation

npm install @rcs-lang/ast

Usage

import * as AST from '@rcs-lang/ast';

// Example: Type-safe AST node creation
const agentNode: AST.AgentDefinition = {
  type: 'AgentDefinition',
  name: 'MyAgent',
  displayName: 'My Agent',
  sections: []
};

// Example: AST traversal with type guards
function visitNode(node: AST.ASTNode) {
  if (AST.isAgentDefinition(node)) {
    console.log('Found agent:', node.name);
  } else if (AST.isFlowDefinition(node)) {
    console.log('Found flow:', node.name);
  }
}

AST Structure

The RCL AST follows a hierarchical structure:

RclFile
├── AgentDefinition
│   ├── ConfigSection
│   ├── DefaultsSection
│   └── FlowDefinition[]
└── MessagesSection
    └── MessageDefinition[]

Key Types

Core Nodes

• RclFile - Root node of an RCL document
• AgentDefinition - Defines an RCS agent
• FlowDefinition - Defines a conversation flow
• MessagesSection - Container for message definitions
• MessageDefinition - Defines a message template

Flow Nodes

• StateDefinition - Defines a state in a flow
• TransitionDefinition - Defines transitions between states
• MatchBlock - Pattern matching for user input
• ActionBlock - Actions to perform in a state

Message Nodes

• TextMessage - Simple text message
• RichCardMessage - Rich card with media and buttons
• CarouselMessage - Carousel of multiple cards
• Suggestion - Quick reply or action suggestions

Type Guards

The package provides type guard functions for runtime type checking:

AST.isAgentDefinition(node)
AST.isFlowDefinition(node)
AST.isMessageDefinition(node)
AST.isTextMessage(node)
// ... and more

Contributing

See the main repository README for contribution guidelines.

License

MIT