77 lines
2.1 KiB
JavaScript
77 lines
2.1 KiB
JavaScript
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import { _await_value } from "./_await_value.js";
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export function _async_generator(gen) {
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var front, back;
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function send(key, arg) {
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return new Promise(function(resolve, reject) {
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var request = { key: key, arg: arg, resolve: resolve, reject: reject, next: null };
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if (back) back = back.next = request;
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else {
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front = back = request;
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resume(key, arg);
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}
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});
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}
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function resume(key, arg) {
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try {
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var result = gen[key](arg);
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var value = result.value;
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var wrappedAwait = value instanceof _await_value;
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Promise.resolve(wrappedAwait ? value.wrapped : value).then(function(arg) {
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if (wrappedAwait) {
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resume("next", arg);
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return;
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}
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settle(result.done ? "return" : "normal", arg);
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}, function(err) {
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resume("throw", err);
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});
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} catch (err) {
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settle("throw", err);
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}
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}
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function settle(type, value) {
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switch (type) {
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case "return":
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front.resolve({ value: value, done: true });
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break;
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case "throw":
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front.reject(value);
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break;
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default:
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front.resolve({ value: value, done: false });
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break;
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}
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front = front.next;
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if (front) resume(front.key, front.arg);
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else back = null;
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}
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this._invoke = send;
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if (typeof gen.return !== "function") this.return = undefined;
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}
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if (typeof Symbol === "function" && Symbol.asyncIterator) {
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_async_generator.prototype[Symbol.asyncIterator] = function() {
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return this;
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};
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}
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_async_generator.prototype.next = function(arg) {
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return this._invoke("next", arg);
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};
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_async_generator.prototype.throw = function(arg) {
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return this._invoke("throw", arg);
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};
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_async_generator.prototype.return = function(arg) {
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return this._invoke("return", arg);
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};
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export { _async_generator as _ };
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