Semantic Error Reporting

Your Task

Implement a comprehensive semantic error reporting system.

Requirements

1. Create an error reporting infrastructure:

   • SemanticError struct with severity, location, message
   • Error collection that gathers all errors
   • Pretty-printing with source context

2. Implement error detectors for:

   • Undefined variable/function references
   • Type mismatches in assignments
   • Type mismatches in operations
   • Wrong function argument count/types
   • Missing return statements
   • Invalid break/continue (outside loops)

3. Implement warning detection:

   • Unused variables
   • Shadowed variables
   • Implicit type conversions
   • Missing return in some paths

4. Create formatted output:

   • Show source line with error
   • Underline the problematic part
   • Include error codes for documentation

Success Criteria

• Detect multiple errors in one pass
• Show source context in error messages
• Distinguish errors from warnings
• Exit with appropriate code (0 = success, 1 = errors)