Parser Optimization, Performance Enhancements & Code Cleanup

[vagetman]

🛠️ Parser and Evaluation Optimization

🚀 Overview

This PR refactors the expression evaluation and parsing logic to improve performance, maintainability, and correctness. The main changes include removing unnecessary allocations, and optimizing string handling.

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🔑 Key Changes

Optimized String Handling

• Replaced String in Value::Text with Cow<'static, str> to reduce unnecessary allocations and improve efficiency by avoiding cloning where possible.
• Updated EvalContext to use Cow for efficient storage and retrieval of variables, ensuring that string data is managed more effectively.

Improved Expression Evaluation (eval_expr)

• Eliminated redundant .to_string() conversions, which were causing unnecessary string allocations.
• Ensured efficient variable resolution by using borrowed references instead of cloned strings, reducing memory usage.

Enhanced Error Messages & Documentation

• Improved error messages for better debugging and user feedback.
• Added comments to clarify logic in key parsing functions, enhancing code readability and maintainability.

Testing and Validation

• Expanded Test Coverage: Introduced new test cases to cover previously untested scenarios, ensuring robustness and catching edge cases.
• Bug Fixes: Addressed known issues and edge cases that were causing unexpected behavior in certain conditions, improving reliability.

Code Refactoring & Cleanup

• Simplified Logic: Refactored complex conditional statements and loops for better readability, efficiency, and to reduce potential for errors.
• Consistent Formatting: Applied uniform code formatting and styling to enhance code consistency and maintainability.

Performance Enhancements

• Optimized Parsing Logic: Improved the ESI parsing mechanism to handle edge cases more efficiently, reducing processing time.
• Reduced Memory Footprint: Implemented more efficient data structures, leading to lower memory consumption and better performance in memory-constrained environments

📈 Impact

✅ Better Performance – Fewer memory allocations, faster evaluation, and optimized parsing logic.
✅ Lower Memory Usage – Reduced heap allocations using Cow<'static, str> and optimized data structures.
✅ Simplified Code – Refactored complex logic, and improved formatting for better readability.
✅ Improved Maintainability – Cleaner parsing logic, better error messages, and enhanced documentation.

[tyler]

Thanks for this :)

[tyler]

Why the rename of String to Text?

[tyler]

Oh, also why not convert everything to &str? Just trying to avoid all the lifetimes?