loot-condition-interpreter/README.md

loot-condition-interpreter
==========================

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A library for parsing and evaluating LOOT's metadata condition strings. It
provides:

- Supports metadata syntax v0.14 condition strings.
- Condition string parsing without evaluation, for checking syntax.
- Evaluation of parsed condition strings.
- Efficient and safe concurrent condition evaluation thanks to Rust's safety 
  guarantees.
- Caching of individual function evaluation results and calculated CRCs.
- Executable version parsing without any external runtime dependencies.
- Lots of tests, and benchmarks.
- A C FFI library that wraps the Rust library.

## Build

Make sure you have [Rust](https://www.rust-lang.org/) installed.

To build the Rust and C FFI libraries, run:

```
cargo build --release --package loot-condition-interpreter-ffi
```

To generate a C++ header file as part of the build, instead run:

```
cargo build --release --package loot-condition-interpreter-ffi --all-features
```

This will create a file at `ffi/include/loot_condition_interpreter.hpp`.
However, this involves building [cbindgen](https://github.com/eqrion/cbindgen)
as a dependency, which is relatively slow. If you have cbindgen installed
separately, it's faster to generate the headers using its CLI:

```
cbindgen ffi/ -l c++ -o ffi/include/loot_condition_interpreter.hpp
```

## Tests & Benchmarks

The tests and benchmarks need the [testing-plugins](https://github.com/WrinklyNinja/testing-plugins)
and the [LOOT API v0.13.8](https://github.com/loot/loot-api/releases/tag/0.13.8)
Windows archives to be extracted and present in the repo root. See the AppVeyor
and Travis CI configurations for examples on what should be extracted where.

To run the Rust tests:

```
cargo test --all
```

To run the benchmarks:

```
cargo bench
```

There are also C++ tests for the FFI library, they require a C++ toolchain and
[CMake](https://cmake.org/) to be installed. To run the C++ tests:

```
mkdir ffi/build
cd ffi/build
cmake ..
cmake --build .
ctest
```