(module
(func (export "select_simple") (result i32)
;; load two values onto the stack
i32.const 10
i32.const 20
;; change to `1` (true) to get the first value (`10`)
i32.const 0
select
)
(func (export "select_externref") (param $value externref) (param $condition i32) (result externref)
;; this is "select t", the explicitly typed variant
ref.null extern
local.get $value
local.get $condition
select (result externref)
)
)
const url = '{%wasm-url%}';
await WebAssembly.instantiateStreaming(fetch(url)).then((result) => {
const { select_simple, select_externref } = result.instance.exports;
console.log(select_simple());
// Expected output: 20
// If the second parameter is zero, returns the first parameter (which may be an arbitrary JS value)
const map = new Map();
console.log(select_externref(map, 0));
// Expected output: [object Map]
console.log(select_externref(map, -1));
// Expected output: null
});