Instruction file imported from SuzumiyaAoba/tpeg (.cursor/rules/parser.mdc). Copyright stays with the author.

Parser Implementation Guidelines

Core Principles

• Document each parser function with clear input/output descriptions
• Include usage examples for complex parsers
• Ensure all parsers handle edge cases and provide meaningful error messages
• Avoid infinite recursion and ensure proper termination conditions
• Follow the PEG (Parsing Expression Grammar) principles consistently
• Consider error recovery for user-facing parsers

Parser Design

• Design parsers to be composable and reusable
• Use clear abstractions that allow for extension
• Provide meaningful error messages with position information
• Handle whitespace and comments appropriately
• Support both consuming and non-consuming parsers
• Implement proper backtracking behavior

Error Handling

• Provide descriptive error messages that include:
  • Expected input format
  • Actual input received
  • Position information
• Use structured error types for different failure modes
• Support error recovery mechanisms where appropriate
• Maintain parse state consistency during error conditions

Combinator Patterns

• Follow functional programming principles
• Make combinators pure functions when possible
• Use consistent naming patterns for similar operations
• Document combinator behavior and usage patterns
• Provide type-safe combinator interfaces