Getting Started

Welcome to the mocha documentation

mocha is a lightweight, fast and efficient Molang lexer, parser, interpreter and compiler for Java 8+. Molang is a simple expression-based language designed for fast and data-driven calculation of values at run-time.

For more information about the Molang language, check their official documentation at learn.microsoft.com.


  • Fast computing. mocha can compile Molang expressions directly to JVM bytecode, no need to parse and interpret the expression every time, zero overhead.
  • Extensive API, you can bind objects and functions to the Molang expression environment, so that they can be called from the evaluated expressions.
  • Lightweight, mocha is a small library with a single dependency: javassist, it's easy to integrate in your project.

mocha vs other Molang libraries

Here are some (reduced) results from a benchmark comparing mocha with other Molang libraries, ordered from fastest to slowest. (To run the benchmark yourself, run ./gradlew jmh)

   Benchmark                            Mode      Cnt       Score   Error  Units
1. unnamed's mocha                    sample  8874677       0.035 ± 0.006  us/op
2. MoonflowerTeam's molang-compiler   sample  7507288       0.041 ± 0.007  us/op
3. bedrockk's MoLang                  sample  5404802       6.449 ± 0.158  us/op

To run the benchmark yourself, run ./gradlew jmh. You can also check the benchmark source code here.