Embedding the Frege compiler

[deliciouslytyped]

Hi, thanks for working on Frege it seems like a great project.

I would like to embed Frege in another application that supports a scripting interface (I don't want to use it just for "scripting" though.) so that I can get Haskell language support.

I searched everywhere I could and the only information I could find is at https://groups.google.com/forum/#!topic/frege-programming-language/hL0b1dVfgLc

I'm not very experienced with java and I didn't see any APIs that would clearly be what I want.

How can I go about embedding the Frege compiler jar in an application, call it/pass some source code files to it, and get something I can run out of it?

I imagine the overall steps would be something like the following:

• Have the Frege compiler on the classpath
• initialize the compiler / pass some files to it
• get some java classes (?) out of it
• run the java stuff
• pass do things back and forth over FFI
• be happy

Edit:
To clarify: I would like the capability to compile and run code at "runtime", and not just loading some precompiled code.

I saw mentions of a scripting API, but I'm not sure if that's appropriate for running "proper" programs?

[Ingo60]

It looks like you're after frege-repl or frege-interpreter or both.

[deliciouslytyped]

Thanks, https://github.com/Frege/frege-interpreter/tree/master/frege-interpreter-java-support looks relevant to what I want. Do I need to read the source to figure out how to use it?

[Ingo60]

This https://github.com/Frege/frege-interpreter/blob/master/frege-interpreter-core/src/test/java/frege/interpreter/scriptengine/FregeScriptEngineTest.java could give you an idea how to use the script interface at least. As I understand it, this should be quite standard-ish and alike no matter what scripting language is used. (But I never did such stuff myself.)

[deliciouslytyped]

I think the current JSR 223 API is explained here https://docs.oracle.com/javase/9/scripting/java-scripting-api.htm , but I'm not sure.

per Wikipedia: The specification, however, was withdrawn later on December 13, 2016 after a Maintenance Review Ballot,[1] where it was decided that this functionality would be included as an integral part of Java 9 and onward.
( https://en.wikipedia.org/wiki/Scripting_for_the_Java_Platform )

Is this tied to java 1.8 or do I just bump the version?
https://github.com/Frege/frege-interpreter/blob/a1d81b6112e722c20eb45c2810ca7903aa65b321/frege-interpreter-java-support/src/main/java/frege/interpreter/javasupport/MemoryJavaCompiler.java#L51

Thanks!

[Ingo60]

The 1.8 is just an option for the javac compiler. It makes sure compiled Frege code can run with a jdk8. It is not so important in the REPL, where any JDK >= 1.8 would theoretically do, but 1.8 is the lowest common denominator, so to speak.

[deliciouslytyped]

I'm still interested in this but haven't had the spare cycles to pursue it.
The goal would be to try to do something similar to https://github.com/edmcman/ghidra-scala-loader .