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'use strict';
const {
ERR_INVALID_ARG_TYPE
} = require('internal/errors').codes;
function from(Readable, iterable, opts) {
let iterator;
if (iterable && iterable[Symbol.asyncIterator])
iterator = iterable[Symbol.asyncIterator]();
else if (iterable && iterable[Symbol.iterator])
iterator = iterable[Symbol.iterator]();
else
throw new ERR_INVALID_ARG_TYPE('iterable', ['Iterable'], iterable);
const readable = new Readable({
objectMode: true,
...opts
});
// Reading boolean to protect against _read
// being called before last iteration completion.
let reading = false;
readable._read = function() {
if (!reading) {
reading = true;
next();
}
};
async function next() {
try {
const { value, done } = await iterator.next();
if (done) {
readable.push(null);
} else if (readable.push(await value)) {
next();
} else {
reading = false;
}
} catch (err) {
readable.destroy(err);
}
}
return readable;
}
module.exports = from;
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