use wasmtime::*;

println!("Initializing...");

let engine = Engine::default();

let mut store = Store::new(&engine, ());

// Compile.

println!("Compiling module...");

let module = Module::from_file(&engine, "examples/multi.wat")?;

// Create a host function which takes multiple parameters and returns

// multiple results.

println!("Creating callback...");

let callback_func = Func::wrap(&mut store, |a: i32, b: i64| -> (i64, i32) {

(b + 1, a + 1)

});

// Instantiate.

println!("Instantiating module...");

let instance = Instance::new(&mut store, &module, &[callback_func.into()])?;

// Extract exports.

println!("Extracting export...");

let g = instance.get_typed_func::<(i32, i64), (i64, i32), _>(&mut store, "g")?;

// Call `$g`.

println!("Calling export \"g\"...");

let (a, b) = g.call(&mut store, (1, 3))?;

println!("Printing result...");

println!("> {} {}", a, b);

assert_eq!(a, 4);

assert_eq!(b, 2);

// Call `$round_trip_many`.

println!("Calling export \"round_trip_many\"...");

let round_trip_many = instance

.get_typed_func::<

(i64, i64, i64, i64, i64, i64, i64, i64, i64, i64),

(i64, i64, i64, i64, i64, i64, i64, i64, i64, i64),

_,

>

(&mut store, "round_trip_many")?;

let results = round_trip_many.call(&mut store, (0, 1, 2, 3, 4, 5, 6, 7, 8, 9))?;

println!("Printing result...");

println!("> {:?}", results);

assert_eq!(results, (0, 1, 2, 3, 4, 5, 6, 7, 8, 9));

Ok(())