feat: add array/base/count-ifs

lib/node_modules/@stdlib/array/base/count-ifs/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2025 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.
+
+-->
+
+# countIfs
+
+> Perform element-wise evaluation of one or more input arrays according to provided predicate functions and count the number of elements for which all predicates respectively return `true`.
+
+<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<!-- Package usage documentation. -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var countIfs = require( '@stdlib/array/base/count-ifs' );
+```
+
+#### countIfs( x0, predicate0\[, x1, predicate1\[, x2, predicate2\[, ...args]] )
+
+Performs element-wise evaluation of one or more input arrays according to provided predicate functions and counts the number of elements for which all predicates respectively return `true`.
+
+```javascript
+function predicate0( value ) {
+    return ( value > 0 );
+}
+
+function predicate1( value ) {
+    return ( value < 3 );
+}
+
+var x0 = [ 0, 1, 0, 1, 2 ];
+var x1 = [ 2, 3, 1, 2, 5 ];
+
+var out = countIfs( x0, predicate0, x1, predicate1 );
+// returns 1
+```
+
+The function has the following parameters:
+
+-   **x0**: first input array.
+-   **predicate0**: first predicate function.
+-   **x1**: second input array (_optional_).
+-   **predicate1**: second predicate function (_optional_).
+-   **x2**: third input array (_optional_).
+-   **predicate2**: third predicate function (_optional_).
+-   **args**: additional input arrays and corresponding predicate functions (_optional_).
+
+Each predicate function is provided three arguments:
+
+-   **value**: current array element.
+-   **index**: current array element index.
+-   **arr**: the corresponding input array.
+
+</section>
+
+<!-- /.usage -->
+
+<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+## Notes
+
+-   The function assumes that all input arrays have the same length.
+-   The function supports array-like objects supporting the accessor protocol (e.g., [`Complex128Array`][@stdlib/array/complex128], [`Complex64Array`][@stdlib/array/complex64], etc).
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+<!-- eslint-disable max-len -->
+
+```javascript
+var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
+var isPositiveInteger = require( '@stdlib/assert/is-positive-integer' ).isPrimitive;
+var isNegativeInteger = require( '@stdlib/assert/is-negative-integer' ).isPrimitive;
+var naryFunction = require( '@stdlib/utils/nary-function' );
+var countIfs = require( '@stdlib/array/base/count-ifs' );
+
+var x = discreteUniform( 10, -5, 5, {
+    'dtype': 'int32'
+});
+console.log( x );
+
+var y = discreteUniform( 10, -5, 5, {
+    'dtype': 'int32'
+});
+console.log( y );
+
+var out = countIfs( x, naryFunction( isPositiveInteger, 1 ), y, naryFunction( isNegativeInteger, 1 ) );
+console.log( out );
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="references">
+
+</section>
+
+<!-- /.references -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+</section>
+
+<!-- /.related -->
+
+<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="links">
+
+[@stdlib/array/complex128]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/complex128
+
+[@stdlib/array/complex64]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/complex64
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/array/base/count-ifs/benchmark/benchmark.length.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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 isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' ).isPrimitive;
+var uniform = require( '@stdlib/random/array/uniform' );
+var pkg = require( './../package.json' ).name;
+var countIfs = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* First predicate function.
+*
+* @private
+* @param {number} v - value
+* @returns {boolean} result
+*/
+function predicate0( v ) {
+	return v > 0.0;
+}
+
+/**
+* Second predicate function.
+*
+* @private
+* @param {number} v - value
+* @returns {boolean} result
+*/
+function predicate1( v ) {
+	return v < 0.0;
+}
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var x0 = uniform( len, -1.0, 1.0, {
+		'dype': 'generic'
+	});
+	var x1 = uniform( len, -1.0, 1.0, {
+		'dype': 'generic'
+	});
+	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 = countIfs( x0, predicate0, x1, predicate1 );
+			if ( typeof out !== 'number' ) {
+				b.fail( 'should return a number' );
+			}
+		}
+		b.toc();
+		if ( !isNonNegativeInteger( out ) ) {
+			b.fail( 'should return a nonnegative integer' );
+		}
+		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+':dtype=generic,predicates=2,len='+len, f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/array/base/count-ifs/docs/repl.txt

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+
+{{alias}}( x0, predicate0[, x1, predicate1[, x2, predicate2[, ...args]] )
+    Performs element-wise evaluation of one or more input arrays according to
+    provided predicate functions and counts the number of elements for which all
+    predicates respectively return `true`.
+
+    Each predicate function is provided three arguments:
+
+    - value: current array element.
+    - index: current array element index.
+    - arr: the corresponding input array.
+
+    Parameters
+    ----------
+    x0: ArrayLikeObject
+        First input array.
+
+    predicate0: Function
+        First predicate function.
+
+    x1: ArrayLikeObject (optional)
+        Second input array.
+
+    predicate1: Function (optional)
+        Second predicate function.
+
+    x2: ArrayLikeObject (optional)
+        Third input array.
+
+    predicate2: Function (optional)
+        Third predicate function.
+
+    ...args: ArrayLikeObject|Function (optional)
+        Additional input arrays and corresponding predicate functions.
+
+    Returns
+    -------
+    out: integer
+        Result.
+
+    Examples
+    --------
+    > function f1( v ) { return ( v > 0 ); };
+    > function f2( v ) { return ( v < 0 ); };
+    > var out = {{alias}}( [ 0, 1, 1 ], f1, [ 1, -1, -1 ], f2 )
+    2
+
+    See Also
+    --------
+