Summary

This PR achieves full RFC 9535 compliance for jsonpathly by replacing the ANTLR4 parser with Peggy and implementing all required features.

Key Changes

• Parser Migration: Replaced ANTLR4 with Peggy for smaller bundle size and simpler build
• RFC 9535 Functions: Implemented all 5 function extensions:
  • length(value) - string/array length or object key count
  • count(nodelist) - count of nodes in nodelist
  • match(string, pattern) - full string I-Regexp match
  • search(string, pattern) - substring I-Regexp match
  • value(nodelist) - extract single value from nodelist
• I-Regexp Validation (RFC 9485): Reject non-interoperable regex features
• Normalized Path Format: Single-quoted output with proper escaping
• Build System: Replaced webpack with tsup for modern ESM/CJS dual output

Bug Fixes

• Fixed negative-step slice logic
• Fixed filter expressions with nested queries
• Fixed empty nodelist comparison semantics
• Fixed control character escaping in stringify

Breaking Changes

• Path output format changed from $["key"] to $['key'] (RFC 9535 normalized format)
• Bumped to v3.0.0

Closes

• Closes RFC9535 - Function extensions are not supported ( match, search, count, length, value) #13 - RFC 9535 function extensions (match, search, count, length, value)
• Closes RFC9535 - filter expression does not return expected results #14 - Filter expression results

Test plan

• All 644 tests passing
• 100% line coverage for src/handler and src/parser
• RFC 9535 compliance test suite added
• Consensus test suite updated