NOTE: This project has been moved to https://github.com/lampepfl/monadic-reflection
This project provides support for monadic reflection (Filinski 1994, 2010) to integrate monadic code with direct style code.
The implementation makes use of cats/StackSafeMonad.tailRecM for stack safety. That is, for the user program to be stack safe all reflected monads have to override tailRecM in a stack safe way.
We collected some examples of how to use cats-reflect.
The current cats-reflect API makes use of implicit function types of Dotty.
To implement monadic reflection we require some implementation of (delimited) continuations. At the moment, cats-reflect only runs on a JVM branch called project loom with runtime support for coroutines / delimited continuations.
There are early-access builds available at https://jdk.java.net/loom/.
To build the custom JVM, clone the repository
git clone https://github.com/openjdk/loom
and checkout the continuation branch cont:
git checkout fibers
Detailed instructions on how to build the JDK can be found in the
file doc/building.md, in short those are:
bash configure
make images
Finally, run sbt with the newly built JVM. Assuming you checked out
loom into PATH and built on a mac, run:
sbt -java-home $PATH/build/macosx-x86_64-server-release/images/jdk
Obviously the path needs to be adjusted for other operating systems.
Some performance optimizations of project loom can be enabled by
-XX:-DetectLocksInCompiledFrames -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseNewCode
The implementation uses cats-core for its Monad typeclass.
The examples also use cats-effect.