Recursive Descent Parser

Your Task

Implement a recursive descent parser for arithmetic expressions with proper precedence.

Requirements

1. Create a Parser struct with:

   • Lexer reference
   • Current token
   • Previous token
   • Error state

2. Implement grammar rules as functions:

   • parse_expression(): Entry point, handles lowest precedence
   • parse_equality(): == !=
   • parse_comparison(): < > <= >=
   • parse_term(): + -
   • parse_factor(): * /
   • parse_unary(): - !
   • parse_primary(): literals, identifiers, grouped expressions

3. Implement helper functions:

   • parser_create(Lexer* lexer)
   • parser_advance()
   • parser_check(TokenType type)
   • parser_match(TokenType type)
   • parser_consume(TokenType type, const char* message)

4. Handle parentheses for grouping: (2 + 3) * 4

Success Criteria

• Parse: 2 + 3 * 4 with correct precedence
• Parse: (2 + 3) * 4 with parentheses
• Parse: -x + y with unary minus
• Report syntax errors with helpful messages