go-twig/PROGRESS.md

Twig Implementation Progress

Completed Features

1. Parser Improvements

   • Added parser support for function syntax with arguments
   • Added parser support for new operators: 'is', 'is not', 'matches', 'starts with', 'ends with', 'not in'
   • Added parser support for test conditions ('is defined', 'is empty', etc.)
   • Added conditional expressions (ternary operators)
   • Added array literal support
   • Added evaluator implementations for the new node types

2. Full Filter Support

   • Fixed filter parsing and evaluation to properly handle the pipe (|) character in the tokenizer/parser
   • Ensured filter arguments are passed correctly to filter functions
   • Implemented support for chained filters (e.g., var|filter1|filter2)
   • Verified comprehensive set of standard Twig filters work correctly:
     • Text manipulation: upper, lower, capitalize, trim, etc.
     • Array manipulation: join, split, slice, sort, etc.
     • Type conversion: length/count, keys, etc.
     • Formatting: date, number_format, etc.
   • Added extensive tests for all filter functionality

3. Documentation

   • Updated README with filter information and examples
   • Added comprehensive test suite for filters with various use cases

Recent Improvements

1. Custom Filter and Function Registration

   • Added AddFilter() method to easily register custom filters
   • Added AddFunction() method to easily register custom functions
   • Added AddTest() method to register custom tests
   • Created CustomExtension type for comprehensive extensions
   • Added RegisterExtension() method for registering extension bundles
   • Created example application demonstrating custom extensions

2. Development Mode and Template Caching

   • Added SetDevelopmentMode() method that sets appropriate debug/cache settings
   • Added SetDebug() and SetCache() methods for individual control
   • Improved template loading to respect cache settings
   • Templates are not cached when cache is disabled
   • Added tests to verify caching behavior

3. Template Modification Checking

   • Added TimestampAwareLoader interface for loaders that support modification time checking
   • Implemented modification time tracking in the FileSystemLoader
   • Added cache invalidation based on file modification times
   • Automatic template reloading when files change and auto-reload is enabled
   • Updated Template struct to track the source loader and modification time
   • Added comprehensive tests for file modification detection
   • Added example application demonstrating auto-reload in action

4. Optimized Filter Chain Processing

   • Implemented a specialized filter chain detection and evaluation algorithm
   • Added support for detecting and processing filter chains in a single pass
   • Reduced the number of intermediate allocations for chained filters
   • Improved performance for templates with multiple filters applied to the same value
   • Added tests and benchmarks to verify correctness and performance gains

Recent Improvements

1. Whitespace Control Features
   • Added support for whitespace control modifiers ({{-, -}}, {%-, -%})
   • Implemented the {% spaceless %} tag to remove whitespace between HTML tags
   • Added direct tokenizer support for whitespace control tokens
   • Improved text handling to preserve spaces between words
   • Added tests for all whitespace control features

Future Improvements

2. More Tests

   • Add more comprehensive tests for edge cases
   • Add more benchmarks for different template scenarios

3. Error Handling

   • Improve error messages for filter-related issues
   • Add better debugging support

4. Template Compilation

   • Implement a compiled template format for even faster rendering
   • Add the ability to pre-compile templates for production use