bytebeat.js (v2)

// bytebeat.js (v2)
// by funute - public domain

/**
 * Now in ES6!
 * Run using node like this:
 *
 * $ node bytebeat.js < input.js | pacat --format=u8 --channels=1 --rate=8000 (PulseAudio)
 * $ node bytebeat.js < input.js | aplay --rate=8000 (ALSA)
 *
 * You can also "render" to a raw file like this:
 *
 * $ node bytebeat.js < input.js > output.raw
 *
 * Or you can just run it, enter stuff in, and listen like this:
 *
 * $ node bytebeat.js | aplay --rate=8000
 * ((t >> 10) & 42) * t
 * ^D
 */

if (process.stdout.isTTY) {
    console.log('stdout is tty, exiting');
    process.exit(1);
}

const CHUNK = 1024;
const LIM = Number(process.argv[2]) || -1;
let expr = 'return ';

process.stdin.on('data', (buf) => {
    expr += buf;
});

process.stdin.on('end', () => {
    // hacky "globalization" of Math (!)
    const mathNames = Object.getOwnPropertyNames(Math);
    const mathProps = mathNames.map((prop) => {
        return Math[prop];
    });

    const mfun = new Function(...mathNames, 't', expr);
    const fun = mfun.bind(null, ...mathProps)

    let t = 0;

    function write() {
        let ok = true;
        while (ok && (t < LIM || LIM == -1)) {
            const data = new Buffer(CHUNK);
            for (let k = 0; k < CHUNK; ++k) {
                data[k] = fun(t+k);
            }
            ok = process.stdout.write(data);
            t += CHUNK;
        }
        if (t < LIM || LIM == -1) {
            process.stdout.once('drain', write);
        }
    };
    write();
});

process.stdout.on('error', (err) => {
    if (err.code === 'EPIPE') {
        process.exit(0);
    } else {
        throw(err);
    }
});