There is now an initial version for Idris 2 - 0.2.1 for the JVM. This is compiled from Idris 2 JVM bootstrap version.

Changes:

• Compile initial Idris 2 compiler (0.2.1) with Idris 2 JVM bootstrap version targeting Java 8 bytecode
• Add JVM backend
• Support primitives such as system, IO, network, clock, buffer etc. for JVM backend
• Eliminate tail recursion
• Add debug information such as variable name, file name and line number in bytecode from Idris source
• Compile Idris modules to Java classes at the bytecode level, Idris top level functions to static Java methods and Idris lambdas into Java lambdas with invokedynamic implementing Java Function interface.
• Generate bytecode concurrently for modules
• Generate classes with toString and property getters for Idris constructors
• Infer types to avoid boxing and casting
• Compile Idris list into a Java list
• JVM foreign descriptors supporting static, instance, interface methods and constructor calls

To try it out:

• Unzip idris2-jvm-0.2.1-SNAPSHOT-20210720.zip from here https://github.com/mmhelloworld/Idris2/releases/tag/v0.2.1-SNAPSHOT-20210720
• Add bin directory to PATH variable
• Copy .idris2 directory containing Idris 0.2.1 packages into your home directory.

To compile and run:

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module Main

data Tree a = Leaf
            | Node (Tree a) a (Tree a)

inorder : Tree a -> List a
inorder Leaf = []
inorder (Node left a right) = inorder left ++ [a] ++ inorder right

tree : Tree String
tree = Node
        (Node
          (Node Leaf "3" Leaf)
          "+"
          (Node Leaf "7" Leaf))
        "/"
        (Node Leaf "2" Leaf)

main : IO ()
main = printLn $ inorder tree

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$ idris2 Main.idr -o main

$ java -jar build/exec/main_app/main.jar
["3", "+", "7", "/", "2"]