feat: add subarray prototype method in fixed-endian-factory

lib/node_modules/@stdlib/array/fixed-endian-factory/README.md

@@ -837,6 +837,97 @@ A few notes:
 -   If a target array cannot accommodate all values (i.e., the length of source array plus `i` exceeds the target array length), the method throws an error.
 -   If provided a typed array which shares an [`ArrayBuffer`][@stdlib/array/buffer] with the target array, the method will intelligently copy the source range to the destination range.
 
+<a name="method-subarray"></a>
+
+#### TypedArrayFE.prototype.subarray( \[start\[, end]] )
+
+Copies a portion of a typed array to a new typed array.
+
+```javascript
+
+var fixedEndianFactory = require( '@stdlib/array/fixed-endian-factory' );
+
+var Float64ArrayFE = fixedEndianFactory( 'float64' );
+
+var arr = new Float64ArrayFE( 'little-endian', 5 );
+// returns <Float64ArrayFE>
+
+arr.set( 0, 0 );
+arr.set( 1, 1 );
+arr.set( 2, 2 );
+arr.set( 3, 3 );
+arr.set( 4, 4 );
+
+var out = arr.subarray();
+// returns <Float64ArrayFE>
+
+var len = out.length;
+// returns 5
+
+var bool = out.get( 0 );
+// returns 0
+
+bool = out.get( len-1 );
+// returns 4
+```
+
+By default, the method returns a typed array beginning with the first array element. To specify an alternative array index at which to begin, provide a `start` index (inclusive).
+
+```javascript
+var fixedEndianFactory = require( '@stdlib/array/fixed-endian-factory' );
+
+var Float64ArrayFE = fixedEndianFactory( 'float64' );
+
+var arr = new Float64ArrayFE( 'little-endian', 5 );
+// returns <Float64ArrayFE>
+
+arr.set( 0, 0 );
+arr.set( 1, 1 );
+arr.set( 2, 2 );
+arr.set( 3, 3 );
+arr.set( 4, 4 );
+
+var out = arr.subarray( 1 );
+// returns <Float64ArrayFE>
+
+var len = out.length;
+// returns 4
+
+var bool = out.get( 0 );
+// returns 1
+
+bool = out.get( len-1 );
+// returns 4
+```
+
+By default, the method returns a typed array which includes all array elements after `start`. To limit the number of array elements after `start`, provide an `end` index (exclusive).
+
+```javascript
+var fixedEndianFactory = require( '@stdlib/array/fixed-endian-factory' );
+
+var Float64ArrayFE = fixedEndianFactory( 'float64' );
+
+var arr = new Float64ArrayFE( 'little-endian', 5 );
+
+arr.set( 0, 0 );
+arr.set( 1, 1 );
+arr.set( 2, 2 );
+arr.set( 3, 3 );
+arr.set( 4, 4 );
+
+var out = arr.subarray( 1, -2 );
+// returns <Float64ArrayFE>
+
+var len = out.length;
+// returns 2
+
+var bool = out.get( 0 );
+// returns 1
+
+bool = out.get( len-1 );
+// returns 2
+```
+
 <a name="method-some"></a>
 
 #### TypedArrayFE.prototype.some( predicate\[, thisArg] )

lib/node_modules/@stdlib/array/fixed-endian-factory/benchmark/benchmark.subarray.js

@@ -0,0 +1,55 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2024 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var bench = require( '@stdlib/bench' );
+var pkg = require( './../package.json' ).name;
+var factory = require( './../lib' );
+
+
+// VARIABLES //
+
+var Float64ArrayFE = factory( 'float64' );
+
+
+// MAIN //
+
+bench( pkg+':subarray', function benchmark( b ) {
+	var out;
+	var arr;
+	var i;
+
+	arr = new Float64ArrayFE( 'little-endian', [ 1.0, 2.0, 2.0, 1.0 ] );
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		out = arr.subarray(1, 2);
+		if ( out instanceof Float64ArrayFE === false ) {
+			b.fail( 'should return a TypedArray' );
+		}
+	}
+	b.toc();
+	if ( out instanceof Float64ArrayFE === false ) {
+		b.fail( 'should return a TypedArray' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/array/fixed-endian-factory/benchmark/benchmark.subarray.length.js

@@ -0,0 +1,102 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2023 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var bench = require( '@stdlib/bench' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var pkg = require( './../package.json' ).name;
+var factory = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var Float64Array;
+	var arr;
+	var i;
+	Float64Array = factory( 'float64' );
+	arr = [];
+	for ( i = 0; i < len; i++ ) {
+		arr.push( i );
+	}
+	arr = new Float64Array( 'little-endian', arr );
+
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var out;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			out = arr.subarray();
+			if ( typeof out !== 'object' ) {
+				b.fail( 'should return an object' );
+			}
+		}
+		b.toc();
+		if ( out instanceof Float64Array === false ) {
+			b.fail( 'should return a TypedArray' );
+		}
+		b.pass( 'benchmark finished' );
+		b.end();
+	}
+}
+
+
+// MAIN //
+
+/**
+* Main execution sequence.
+*
+* @private
+*/
+function main() {
+	var len;
+	var min;
+	var max;
+	var f;
+	var i;
+
+	min = 1; // 10^min
+	max = 6; // 10^max
+
+	for ( i = min; i <= max; i++ ) {
+		len = pow( 10, i );
+		f = createBenchmark( len );
+		bench( pkg+':subarray:len='+len, f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/array/fixed-endian-factory/lib/main.js

@@ -1058,6 +1058,101 @@ function factory( dtype ) { // eslint-disable-line max-lines-per-function, stdli
 		buf[ SETTER ]( idx*BYTES_PER_ELEMENT, value, this._isLE );
 	});
 
+	/**
+	* Copies a portion of a typed array to a new typed array.
+ 	* @name subarray
+ 	* @memberof TypedArray.prototype
+ 	* @type {Function}
+ 	* @param {integer} [begin] - start index (inclusive)
+ 	* @param {integer} [end] - end index (exclusive)
+	* @throws {TypeError} `this` must be a typed array instance
+	* @throws {RangeError} first argument must be in the range of `[0, this.length -1]` while second argument must be in the range of `[0, this.length]`
+	* @throws {TypeError} first argument must be integer, and second argument must be integer
+	* @returns {TypedArray} TypedArray array
+	*
+	* @example
+	* var Float64Array = factory('float64');
+	*
+	* var arr = new Float64Array( 'little-endian' , [0.0, 1.0, 2.0, 3.0, 4.0] );
+	*
+	* var out = arr.subarray();
+	* // returns <Float64Array>
+	*
+	* var len = out.length;
+	* // returns 5
+	*
+	* var bool = out.get( 0 );
+	* // returns 0.0
+	*
+	* bool = out.get( len-1 );
+	* // returns 4.0
+	*
+	* out = arr.subarray( 1, -2 );
+	* // returns <Float64Array>
+	*
+	* len = out.length;
+	* // returns 2
+	*
+	* bool = out.get( 0 );
+	* // returns 1.0
+	*
+	* bool = out.get( len-1 );
+	* // returns 2.0
+	*/
+	setReadOnly( TypedArray.prototype, 'subarray', function subarray( begin, end ) {
+		var outbuf;
+		var out;
+		var buf;
+		var len;
+		var i;
+		outbuf = [];
+		if ( !isTypedArray( this ) ) {
+			throw new TypeError( 'invalid invocation. `this` is not a typed array.' );
+		}
+		buf = this._buffer;
+		len = this._length;
+		if ( arguments.length === 0 ) {
+			begin = 0;
+			end = len;
+		} else {
+			if ( !isInteger( begin ) ) {
+				throw new TypeError( format( 'invalid argument. First argument must be an integer. Value: `%s`.', begin ) );
+			}
+			if ( begin < 0 ) {
+				begin += len;
+				if ( begin < 0 ) {
+					begin = 0;
+				}
+			}
+			if ( arguments.length === 1 ) {
+				end = len;
+			} else {
+				if ( !isInteger( end ) ) {
+					throw new TypeError( format( 'invalid argument. Second argument must be an integer. Value: `%s`.', end ) );
+				}
+				if ( end < 0 ) {
+					end += len;
+					if ( end < 0 ) {
+						end = 0;
+					}
+				} else if ( end > len ) {
+					end = len;
+				}
+			}
+		}
+
+		for ( i = begin; i < end; i++ ) {
+			outbuf[ i - begin ] = buf[ GETTER ]( i * BYTES_PER_ELEMENT, this._isLE );
+		}
+
+		if (this._isLE) {
+			out = new this.constructor( 'little-endian', outbuf );
+		} else {
+			out = new this.constructor( 'big-endian', outbuf );
+		}
+		return out;
+	});
+
 	/**
 	* Tests whether at least one element in the typed array passes a test implemented by a predicate function.
 	*
@@ -1070,6 +1165,7 @@ function factory( dtype ) { // eslint-disable-line max-lines-per-function, stdli
 	* @throws {TypeError} first argument must be a function
 	* @returns {boolean} boolean indicating whether at least one element passes a test
 	*/
+
 	setReadOnly( TypedArray.prototype, 'some', function some( predicate, thisArg ) {
 		var buf;
 		var i;