use rune::{Context, Diagnostics, Source, Sources, Vm};
use rune::termcolor::{ColorChoice, StandardStream};
use std::sync::Arc;

let context = Context::with_default_modules()?;
let runtime = Arc::new(context.runtime()?);

let mut sources = Sources::new();
sources.insert(Source::memory("pub fn add(a, b) { a + b }")?);

let mut diagnostics = Diagnostics::new();

let result = rune::prepare(&mut sources)
    .with_context(&context)
    .with_diagnostics(&mut diagnostics)
    .build();

if !diagnostics.is_empty() {
    let mut writer = StandardStream::stderr(ColorChoice::Always);
    diagnostics.emit(&mut writer, &sources)?;
}

let unit = result?;
let mut vm = Vm::new(runtime, Arc::new(unit));

let output = vm.call(["add"], (10i64, 20i64))?;
let output: i64 = rune::from_value(output)?;

println!("{}", output);