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dduan/Makefile

Created December 29, 2017 04:13
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"Hello, World!" In WebAssembly
Raw
main.wat
(module
(memory (export "memory") 1)
(data (i32.const 0) "Hello, world!")
(global (export "length") i32 (i32.const 12))
(global (export "position") i32 (i32.const 0)))
Raw
Makefile
compile:
wat2wasm main.wat -o main.wasm
serve:
python -m SimpleHTTPServer
Raw
play.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script src="play.js"></script>
</body>
</html>
Raw
play.js
function main(wasm) {
const memory = wasm.exports.memory;
const length = wasm.exports.length;
const position = wasm.exports.position;
const bytes = new Uint8Array(memory.buffer, position, length);
const s = new TextDecoder('utf8').decode(bytes);
console.log(s);
}
fetch("main.wasm").then(reponse =>
reponse.arrayBuffer()
).then(bytes =>
WebAssembly.instantiate(bytes, {})
).then(result =>
result.instance
).then(main);
@A1rPun
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A1rPun commented May 11, 2021

This gist helped me getting started. Noticed the length was one short.

  (global (export "length") i32 (i32.const 13))

@komodoooo
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That's the power of science.

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