Module regex_engine 

Dual regex engine abstraction for safe and fast pattern matching.

The regex safety audit (git_safety_guard-99e.11) found:

• ~85% of pack patterns can use the linear-time regex crate
• ~15% require lookahead/lookbehind (needs fancy_regex)

This module provides:

• CompiledRegex: Eagerly compiled abstraction that auto-selects engine
• LazyCompiledRegex: Lazily compiled regex using CompiledRegex (for pack patterns)

The lazy variant avoids regex compilation during pack registry initialization, improving startup latency for the common allow-path case.

Structs

LazyCompiledRegex

A lazily-compiled regex pattern using CompiledRegex.

Enums

CompiledRegex

A compiled regex that auto-selects between linear-time and backtracking engines.

Functions

needs_backtracking_engine

Check if a pattern requires the backtracking engine.