jvm

Functions¶

Java and Kotlin execute through one in-process JNI host. Signatures use Zolo types; bodies use their native language. Import the provider explicitly, then call its functions directly.

use plugin jvm::{java, kotlin}

extern java fn upper(value: str) -> str { return value.toUpperCase(); }
extern kotlin fn greet(name: str) -> str { return "Olá, $name!" }

print(upper("Zolo"))
print(greet("Kotlin"))

int maps to Java long/Kotlin Long; i32 maps to Java int/Kotlin Int. Conversions are checked. Public classes retain native identity through .new, supported methods and mutable fields/properties. Source paths follow the importing Zolo file. Async functions adapt CompletionStage and Kotlin suspend operations to Zolo Futures. Callbacks return to the owning Zolo runtime; exceptions report authored source and support ordinary try/catch.

Declare Maven libraries globally through extern ... deps or [foreign.jvm.dependencies]. Use zolo install and the shared auto/manual/offline/frozen policies. Editor analysis never installs packages or executes authored initializers.

Native Java completion can insert the leading import when accepting a type such as Guava Joiner. Existing imports are reused; conflicting names use qualified insertion. The edits preserve current unsaved text, indentation and UTF-16 positions.

Source preparation/editor queries need a JDK8+. ZOLO_JAVA_HOME selects it. Kotlin additionally needs the pinned compiler and analysis closure, acquired explicitly with python plugins/jvm/tools/install-kotlin.py --destination .zolo-tools/kotlin-2.3.20. Set its printed ZOLO_KOTLIN_HOME/ZOLO_KOTLIN_ANALYSIS_HOME paths.

Artifacts include class files, stdlib and dependency bytes. VM/native/LLVM dynamic/embed/static deployments can use a compatible JRE after removing sources and compilers. Plugin packaging does not bundle Java. Cancellation is cooperative; unsupported varargs/open generic shapes need concrete native wrappers. Windows x64 is verified; hosted wasm-aot execution is unavailable.

See Java examples, Kotlin examples and dependency policies.