Power: Restrict exponent to 32 bit value. Negative exponents truncate…

… to zero (unless value was one).

README.md

@@ -130,8 +130,8 @@ API
 * Long#**clone**(): `Long`<br />
   Returns a deep copy of this Long.
 
-* Long#**power**/**pow**(exp: `Long | number | string`): `Long`<br />
-  Returns this Long to given integer power.
+* Long#**power**/**pow**(exp: `Long | number`): `Long`<br />
+  Returns this Long to given 32bit integer power.
 
 * Long#**equals**/**eq**(other: `Long | number | string`): `boolean`<br />
   Tests if this Long's value equals the specified's.

externs/long.js

@@ -362,13 +362,13 @@ Long.prototype.div = function(other) {};
 Long.prototype.clone = function() {};
 
 /**
- * @param {!Long|number|string} other
+ * @param {!Long|number} other
  * @return {!Long}
  */
 Long.prototype.power = function(other) {};
 
 /**
- * @param {!Long|number|string} other
+ * @param {!Long|number} other
  * @return {!Long}
  */
 Long.prototype.pow = function(other) {};

index.d.ts

@@ -142,14 +142,14 @@ declare class Long {
     clone(): Long;
 
     /**
-     * Returns this Long to given integer power.
+     * Returns this Long to given 32bit integer power.
      */
-    power(exp: Long | number | string): Long;
+    power(exp: Long | number): Long;
 
     /**
-     * Returns this Long to given integer power.
+     * Returns this Long to given 32bit integer power.
      */
-    pow(exp: Long | number | string): Long;
+    pow(exp: Long | number): Long;
 
     /**
      * Tests if this Long's value equals the specified's.

src/long.js

@@ -1096,28 +1096,28 @@ LongPrototype.clone = function clone() {
 };
 
 /**
- * Returns this Long to given integer power.
+ * Returns this Long to given 32bit integer power.
  * @this {!Long}
- * @param {!Long|number|string} exp Integer power
+ * @param {!Long|number} exp Integer power (32bit)
  * @returns {!Long} This Long to given integer power
  */
 LongPrototype.power = function power(exp) {
     var a = this;
-    var b = Long.fromValue(exp);
-    if (b.isZero()) return Long.ONE;
-    if (a.eq(Long.ONE) || b.eq(Long.ONE)) return a;
-    if (b.isNegative()) return Long.ONE.div(a.pow(b.neg())); // being only integers, this will probably always be zero?
-    while (b.isEven()) {
-      b = b.shru(1);
+    if (isLong(exp)) exp = exp.toInt();
+    if (exp===0) return Long.ONE;
+    if (a.eq(Long.ONE) || exp===1) return a;
+    if (exp < 0) return Long.ZERO; // Long.ONE.div(a.pow(-exp)); // being only integers, this will probably always be zero?
+    while ((exp & 1)===0) {
+      exp >>>= 1;
       a = a.mul(a);
     }
-    return a.pow(b.sub(1)).mul(a);
+    return a.pow(exp-1).mul(a);
 };
 
 /**
- * Returns this Long to given integer power. This is an alias of {@link Long#power}.
+ * Returns this Long to given 32bit integer power. This is an alias of {@link Long#power}.
  * @function
- * @param {!Long|number|string} exp Power
+ * @param {!Long|number} exp Power
  * @returns {!Long} This Long to given integer power
  */
 LongPrototype.pow = LongPrototype.power;