feat: add C implementation for math/base/special/falling-factorial

Author: gunjjoshi

lib/node_modules/@stdlib/math/base/special/falling-factorial/benchmark/benchmark.native.js

@@ -1,7 +1,7 @@
 /**
 * @license Apache-2.0
 *
-* Copyright (c) 2018 The Stdlib Authors.
+* 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.
@@ -20,17 +20,26 @@
 
 // MODULES //
 
+var resolve = require( 'path' ).resolve;
 var bench = require( '@stdlib/bench' );
 var randu = require( '@stdlib/random/array/uniform' );
 var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var tryRequire = require( '@stdlib/utils/try-require' );
 var pkg = require( './../package.json' ).name;
-var fallingFactorial = require( './../lib' );
+
+
+// VARIABLES //
+
+var fallingFactorial = tryRequire( resolve( __dirname, './../lib/native.js' ) );
+var opts = {
+	'skip': ( fallingFactorial instanceof Error )
+};
 
 
 // MAIN //
 
-bench( pkg, function benchmark( b ) {
+bench( pkg+'::native', opts, function benchmark( b ) {
 	var x;
 	var n;
 	var y;

lib/node_modules/@stdlib/math/base/special/falling-factorial/examples/c/Makefile

@@ -0,0 +1,31 @@
+/**
+* @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.
+*/
+
+#include "stdlib/math/base/special/falling_factorial.h"
+#include <stdio.h>
+
+int main( void ) {
+	const double x[] = { -10.0, -7.78, -5.56, -3.33, -1.11, 1.11, 3.33, 5.56, 7.78, 10.0 };
+
+	double v;
+	int i;
+	for ( i = 0; i < 10; i++ ) {
+		v = stdlib_base_falling_factorial( x[ i ] );
+		printf( "x: %lf, falling_factorial(x): %lf\n", x[ i ], v );
+	}
+}