77 lines
2.7 KiB
HTML
77 lines
2.7 KiB
HTML
<!doctype html>
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<html lang="en-US">
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<head>
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<meta charset="utf-8" />
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<title>Starlark evaluator</title>
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<style type="text/css">
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body {
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font-family: sans-serif;
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}
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textarea {
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width: calc(100% - 20px);
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height: 20em;
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box-sizing: border-box;
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margin: 5px;
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border-radius: 3px;
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padding: 5px;
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border-color: lightgray;
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}
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</style>
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</head>
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<body>
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<script>
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function run() {
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WebAssembly.instantiateStreaming(fetch("cel_js_example.wasm"), {}).then(({ instance }) => {
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const readString = (offset) => {
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const memory = instance.exports.memory.buffer;
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const length = new Uint32Array(memory, offset, 1)[0];
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const characters = new Uint8Array(memory, offset + 4, length);
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return new TextDecoder().decode(characters);
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};
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const readU8 = (offset) => {
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return new Uint8Array(instance.exports.memory.buffer, offset, 1)[0];
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};
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const writeString = (s) => {
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const encoded = new TextEncoder().encode(s.trim());
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const offset = instance.exports.allocation(4 + encoded.byteLength);
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// TODO(april): this probably isn't guaranteed to be 4-byte aligned? Might need to fix.
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const memory = instance.exports.memory.buffer;
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const uint32s = new Uint32Array(memory, offset, 1);
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uint32s[0] = encoded.byteLength;
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const uint8s = new Uint8Array(memory, offset + 4, encoded.byteLength);
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uint8s.set(encoded);
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return offset;
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};
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const content = document.getElementById("input").value;
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const offset = instance.exports.evaluate(writeString(content));
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const ok = readU8(offset) != 0;
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const result = readString(offset + 4);
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const output = document.getElementById("output");
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output.value = (ok ? "" : "ERROR\n") + result;
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});
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}
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window.addEventListener("load", function () {
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document.getElementById("input").addEventListener("input", run, false);
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run()
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})
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</script>
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<h1>Starlark evaluator</h1>
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<p>
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Using <a href="https://github.com/cel-rust/cel-rust">cel-rust</a> compiled to web assembly.
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Change the input to see it update.
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</p>
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<textarea id="input">
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"Hello " + "world!"</textarea>
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<textarea id="output" readonly="readonly" style="background-color: lightgray;">
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</textarea>
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</body>
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</html>
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