feat: add findIndex method to array/fixed-endian-factory

Author: pranav-1720

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

@@ -338,6 +338,62 @@ v = arr.at( -100 );
 // returns undefined
 ```
 
+<a name="method-find-index"></a>
+
+#### TypedArrayFE.prototype.findIndex( callbackFn\[, thisArg] )
+
+Returns the index of the first element in a typed array that satisfies the provided testing function. 
+If no element satisfies function, return -1.
+
+```javascript
+function greaterthantwo( v ) {
+    return ( v > 2.0 );
+}
+
+var Float64ArrayFE = fixedEndianFactory( 'float64' );
+
+var arr = new Float64ArrayFE( 'little-endian', 3 );
+
+arr.set( 1.5, 0 );
+arr.set( 2.5, 1 );
+arr.set( 3.5, 2 );
+
+var idx = arr.findIndex( greaterthantwo );
+// returns 1
+```
+
+The invoked function is provided three arguments:
+
+-   **value**: current array element.
+-   **index**: current array element index.
+-   **arr**: the array on which this method was called.
+
+To set the function execution context, provide a `thisArg`.
+
+```javascript
+function fcn( v, i ) {
+    this.count += 1;
+    return (v === 2.0);
+}
+
+var Float64ArrayFE = fixedEndianFactory( 'float64' );
+
+var arr = new Float64ArrayFE( 'little-endian', 3 );
+
+var context = {
+    'count': 0
+};
+
+arr.set( 1.0, 0 );
+arr.set( 2.0, 1 );
+arr.set( 3.0, 2 );
+
+arr.findIndex( fcn, context );
+
+var count = context.count;
+// returns 2
+```
+
 <a name="method-for-each"></a>
 
 #### TypedArrayFE.prototype.forEach( callbackFn\[, thisArg] )

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

@@ -0,0 +1,58 @@
+/**
+* @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 isInteger = require( '@stdlib/assert/is-integer' ).isPrimitive;
+var pkg = require( './../package.json' ).name;
+var factory = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg+':findIndex', function benchmark( b ) {
+	var ctor;
+	var arr;
+	var idx;
+	var i;
+
+	ctor = factory( 'float64' );
+	arr = new ctor( 'little-endian', [ 1.0, 2.0, 3.0, 4.0 ] );
+	idx = arr.findIndex( predicate );
+
+	function predicate( v ) {
+		return ( v === 3.0 );
+	}
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		idx = arr.findIndex( predicate );
+		if ( typeof idx !== 'number' ) {
+			b.fail( 'should return an integer' );
+		}
+	}
+	b.toc();
+	if ( !isInteger( idx ) ) {
+		b.fail( 'should return an integer' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

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

@@ -0,0 +1,106 @@
+/**
+* @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 pow = require( '@stdlib/math/base/special/pow' );
+var zeroTo = require( '@stdlib/array/zero-to' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pkg = require( './../package.json' ).name;
+var factory = require( './../lib' );
+
+
+// VARIABLES //
+
+var Float64ArrayFE = factory( 'float64' );
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var	arr = new Float64ArrayFE( 'little-endian', zeroTo(len));
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var idx;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			idx=arr.findIndex( callback );
+			if ( typeof idx !== 'number' ) {
+				b.fail( 'should return an integer' );
+			}
+		}
+		b.toc();
+		if ( arr.length !== len ) {
+			b.fail( 'should not change an array length' );
+		}
+		b.pass( 'benchmark finished' );
+		b.end();
+
+		function callback( value ) {
+			if ( isnan( value ) ) {
+				throw new Error( 'something went wrong' );
+			}
+		}
+	}
+}
+
+
+// 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+':forEach:len='+len, f );
+	}
+}
+
+main();

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

@@ -538,6 +538,39 @@ function factory( dtype ) { // eslint-disable-line max-lines-per-function, stdli
 	*/
 	setReadOnly( TypedArray.prototype, 'BYTES_PER_ELEMENT', TypedArray.BYTES_PER_ELEMENT );
 
+	/**
+	* Invokes a function once for each array element.
+	*
+	* @name findIndex
+	* @memberof TypedArray.prototype
+	* @type {Function}
+	* @param {Function} callbackFn - function to invoke
+	* @param {*} [thisArg] - function invocation context
+	* @throws {TypeError} `this` must be a typed array instance
+	* @throws {TypeError} first argument must be a function
+	*/
+	setReadOnly( TypedArray.prototype, 'findIndex', function findIndex( fcn, thisArg ) {
+		var result;
+		var buf;
+		var i;
+
+		if ( !isTypedArray( this ) ) {
+			throw new TypeError( format( 'invalid invocation. `this` is not %s %s.', CHAR2ARTICLE[ dtype[0] ], CTOR_NAME ) );
+		}
+		if ( !isFunction( fcn ) ) {
+			throw new TypeError( format( 'invalid argument. First argument must be a function. Value: `%s`.', fcn ) );
+		}
+
+		buf = this._buffer;
+		for (i = 0; i < this._length; i++) {
+			result = fcn.call(thisArg, buf[GETTER](i * BYTES_PER_ELEMENT, this._isLE), i, this);
+			if (result) {
+				return i;
+			}
+		}
+		return -1; // Not found
+	});
+
 	/**
 	* Invokes a function once for each array element.
 	*