Enhance type definitions in Matrix and Tensor classes (#976)

Author: ishii-norimi

lib/util/matrix.js

@@ -1316,33 +1316,43 @@ export default class Matrix {
 		return r
 	}
 
+	/**
+	 * Returns a matrix reduced along all element with the callback function.
+	 * @overload
+	 * @param {function (T, T, number[], Matrix<T>): T} cb Reducing function
+	 * @param {undefined | null} [init] Initial value
+	 * @returns {T} Reduced value
+	 */
 	/**
 	 * Returns a matrix reduced along all element with the callback function.
 	 * @template U
 	 * @overload
 	 * @param {function (U, T, number[], Matrix<T>): U} cb Reducing function
-	 * @param {U} [init] Initial value
+	 * @param {U} init Initial value
 	 * @returns {U} Reduced value
 	 */
 	/**
 	 * Returns a matrix reduced along the axis with the callback function.
-	 * @template U
+	 * @template {number | number[]} A
+	 * @template {boolean} F
 	 * @overload
-	 * @param {function (U, T, number[], Matrix<T>): U} cb Reducing function
-	 * @param {U} init Initial value
-	 * @param {0 | 1} axis Axis to be reduced
-	 * @param {boolean} [keepdims] Keep dimensions or not. If null, negative axis retuns number and other axis returns Matrix.
-	 * @returns {Matrix<U>} Reduced matrix
+	 * @param {function (T, T, number[], Matrix<T>): T} cb Reducing function
+	 * @param {undefined | null} init Initial value
+	 * @param {A} axis Axis to be reduced
+	 * @param {F} [keepdims] Keep dimensions or not. If null, negative axis retuns number and other axis returns Matrix.
+	 * @returns {Matrix<T> | (A extends 0 | 1 ? never : F extends true ? never : T)} Reduced matrix
 	 */
 	/**
 	 * Returns a matrix reduced along the axis with the callback function.
 	 * @template U
+	 * @template {number | number[]} A
+	 * @template {boolean} F
 	 * @overload
 	 * @param {function (U, T, number[], Matrix<T>): U} cb Reducing function
 	 * @param {U} init Initial value
-	 * @param {number | number[]} axis Axis to be reduced. If negative, reduce along all elements.
-	 * @param {boolean} [keepdims] Keep dimensions or not. If null, negative axis retuns number and other axis returns Matrix.
-	 * @returns {Matrix<U> | U} Reduced matrix or value
+	 * @param {A} axis Axis to be reduced
+	 * @param {F} [keepdims] Keep dimensions or not. If null, negative axis retuns number and other axis returns Matrix.
+	 * @returns {Matrix<U> | (A extends 0 | 1 ? never : F extends true ? never : U)} Reduced matrix
 	 */
 	/**
 	 * @template U