diff --git a/noname/gnc/index.js b/noname/gnc/index.js
index 3f42741f5..df5a6d83b 100644
--- a/noname/gnc/index.js
+++ b/noname/gnc/index.js
@@ -1,53 +1,51 @@
 import { GeneratorFunction, Uninstantable } from "../util/index.js";
-
-class Is extends Uninstantable {
-	static coroutine(item) {
-		return typeof item == "function" && item.name == "genCoroutine";
-	}
-	static generatorFunc(item) {
-		return item instanceof GeneratorFunction;
-	}
-	static generator(item) {
-		return (typeof item == "object") && ("constructor" in item) && item.constructor && ("constructor" in item.constructor) && item.constructor.constructor === GeneratorFunction;
-	}
-};
+import { Is } from "./is.js";
 
 // gnc: GeNCoroutine
 export class GNC extends Uninstantable {
+	/**
+	 * @param {GeneratorFunction} fn 
+	 * @returns 
+	 */
 	static of(fn) {
-		return gnc.is.generatorFunc(fn) ? function genCoroutine() {
-			let gen = fn.apply(this, arguments);
-			gen.status = "next";
-			gen.state = undefined;
-			const callback = (resolve, reject) => {
-				let result,
-					nexts = resolve,
-					throws = reject;
-				try {
-					result = gen[gen.status](gen.state);
-				} catch (error) {
-					reject(error);
-					return;
-				}
-				if (!result.done) {
-					nexts = (item) => {
-						gen.state = item;
-						gen.status = "next";
-						callback(resolve, reject);
+		return Is.generatorFunc(fn) ?
+			/**
+			 * @param {Parameters<typeof fn>} args
+			 * @returns {Promise<ReturnType<typeof fn>>}
+			 */
+			function genCoroutine(...args) {
+				let gen = fn.apply(this, args);
+				gen.status = "next";
+				gen.state = undefined;
+				const callback = (resolve, reject) => {
+					let result,
+						nexts = resolve,
+						throws = reject;
+					try {
+						result = gen[gen.status](gen.state);
+					} catch (error) {
+						reject(error);
+						return;
 					}
-					throws = (err) => {
-						gen.state = err;
-						gen.status = "throw";
-						callback(resolve, reject);
+					if (!result.done) {
+						nexts = (item) => {
+							gen.state = item;
+							gen.status = "next";
+							callback(resolve, reject);
+						};
+						throws = (err) => {
+							gen.state = err;
+							gen.status = "throw";
+							callback(resolve, reject);
+						};
 					}
-				}
-				result = result.value;
-				Promise.resolve(result).then(nexts, throws);
-			}
-			return new Promise(callback);
-		} : (() => { throw new TypeError("gnc.of needs a GeneratorFunction.") })()
+					result = result.value;
+					Promise.resolve(result).then(nexts, throws);
+				};
+				return new Promise(callback);
+			} : (() => { throw new TypeError("gnc.of needs a GeneratorFunction."); })();
 	}
 	static is = Is;
 };
 
-export const gnc = GNC;
\ No newline at end of file
+export const gnc = GNC;
diff --git a/noname/gnc/is.js b/noname/gnc/is.js
new file mode 100644
index 000000000..7089fa988
--- /dev/null
+++ b/noname/gnc/is.js
@@ -0,0 +1,27 @@
+import { GeneratorFunction, Uninstantable } from "../util/index.js";
+
+export class Is extends Uninstantable {
+	/**
+	 * @param {*} item 
+	 * @returns {boolean}
+	 */
+	static coroutine(item) {
+		return typeof item == "function" && item.name == "genCoroutine";
+	}
+
+	/**
+	 * @param {*} item 
+	 * @returns {boolean}
+	 */
+	static generatorFunc(item) {
+		return item instanceof GeneratorFunction;
+	}
+
+	/**
+	 * @param {*} item 
+	 * @returns {boolean}
+	 */
+	static generator(item) {
+		return (typeof item == "object") && ("constructor" in item) && item.constructor && ("constructor" in item.constructor) && item.constructor.constructor === GeneratorFunction;
+	}
+};