feat add copyWithIn method to array/uint64

lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.get.js

@@ -36,8 +36,7 @@ bench( format( '%s:get', pkg ), function benchmark( b ) {
 	var v;
 	var i;
 
-	arr = zeroTo( 10, 'generic' );
-	arr = new Uint64Array( arr );
+	arr = new Uint64Array( zeroTo( 10, 'generic' ) );
 	N = arr.length;
 
 	b.tic();

lib/node_modules/@stdlib/array/uint64/lib/main.js

@@ -597,6 +597,46 @@
 */
 setReadOnly( Uint64Array.prototype, 'BYTES_PER_ELEMENT', Uint64Array.BYTES_PER_ELEMENT );
 
+/**
+* Copies a sequence of elements within the array to the position starting at `target`.
+*
+* @name copyWithin
+* @memberof Uint64Array.prototype
+* @type {Function}
+* @param {integer} target - index at which to start copying elements
+* @param {integer} start - source index at which to copy elements from
+* @param {integer} [end] - source index at which to stop copying elements from
+* @throws {TypeError} `this` must be a 64-bit unsigned integer array
+* @returns {Uint64Array} modified array
+*
+* @example
+* var Uint64 = require( '@stdlib/number/uint64/ctor' );
+*
+* var arr = new Uint64Array( 4 );
+*
+* // Set the array elements:
+* arr.set( 1, 0 );
+* arr.set( 2, 1 );
+* arr.set( 3, 2 );
+* arr.set( 4, 3 );
+*
+* // Copy the first two elements to the last two elements:
+* arr.copyWithin( 2, 0, 2 );
+* // arr => <Uint64Array>[ 1n, 2n, 1n, 2n ]
+*/
+setReadOnly( Uint64Array.prototype, 'copyWithin', function copyWithin( target, start ) {
+	if ( !isUint64Array( this ) ) {
+		throw new TypeError( 'invalid invocation. `this` is not a 64-bit unsigned integer array.' );
+	}
+	// FIXME: prefer a functional `copyWithin` implementation which addresses lack of universal browser support (e.g., IE11 and Safari) or ensure that typed arrays are polyfilled
+	if ( arguments.length === 2 ) {
+		this._buffer.copyWithin( target*2, start*2 );
+	} else {
+		this._buffer.copyWithin( target*2, start*2, arguments[2]*2 );
+	}
+	return this;
+});
+
 /**
 * Returns an iterator for iterating over array key-value pairs.
 *
@@ -846,7 +886,7 @@
 		buf[ idx+indices.LOW ] = words[ 1 ];
 		return;
 	}
 	if ( isNonNegativeInteger( value ) || ( isBigInt( value ) && isNonNegativeInteger( Number( value ) ) ) ) {
 		if ( idx >= this._length ) {
 			throw new RangeError( format( 'invalid argument. Index argument is out-of-bounds. Value: `%u`.', idx ) );
 		}
@@ -909,7 +949,7 @@
 			// We need to copy source values...
 			tmp = new Uint32Array( sbuf.length );
 			for ( i = 0; i < sbuf.length; i++ ) {
 				tmp[ i ] = sbuf[ i ]; // TODO: handle accessor arrays
 			}
 			sbuf = tmp;
 		}