An experimental library for parsing and evaluating LOOT's metadata condition strings. This library improves upon LOOT's existing implementation in the following ways:

Condition expressions are parsed into an intermediate representation instead of being stringly typed, which allows parsing and evaluation to be separated.
State is uncoupled by necessity, and Rusts's concurrency guarantees mean it can be accessed more efficiently.
Results are cached with more granularity, per function instead of per expression, improving performance when expressions are not entirely different.
Result caching is guided by benchmarks, so results aren't cached unnecessarily.
Reading executable versions doesn't involve calling out to the shell and piping several commands together when on Linux.

The code is also not as much of a mess, it's got benchmarks, and probably better test coverage.

The library is still experimental because it currently lacks:

an FFI for LOOT to call it through.
good error handling, details about parsing errors are not exposed.

The tests need the testing-plugins and the LOOT API v0.13.8 Windows archives to be extracted and present in the repo root.