Auto-generated commit

base/filter/README.md

@@ -0,0 +1,156 @@
+<!--
+
+@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.
+
+-->
+
+# filter
+
+> Return a shallow copy of an array containing only those elements which pass a test implemented by a predicate function.
+
+<!-- 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 filter = require( '@stdlib/array/base/filter' );
+```
+
+#### filter( x, predicate\[, thisArg] )
+
+Returns a shallow copy of an array containing only those elements which pass a test implemented by a `predicate` function.
+
+```javascript
+function isPositive( value ) {
+    return ( value > 0 );
+}
+
+var x = [ 1, -2, -3, 4 ];
+
+var out = filter( x, isPositive );
+// returns [ 1, 4 ]
+```
+
+The `predicate` function is provided three arguments:
+
+-   **value**: current array element.
+-   **index**: current array element index.
+-   **arr**: input array.
+
+To set the `predicate` function execution context, provide a `thisArg`.
+
+```javascript
+function predicate( value ) {
+    this.count += 1;
+    return ( value > 0 );
+}
+
+var x = [ 1, 2, -3, 4 ];
+
+var context = {
+    'count': 0
+};
+
+var out = filter( x, predicate, context );
+// returns [ 1, 2, 4 ]
+
+var cnt = context.count;
+// returns 4
+```
+
+</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
+
+-   If provided an array-like object having a `filter` method, the function defers execution to that method and assumes that the method API has the following signature:
+
+    ```text
+    x.filter( predicate, thisArg )
+    ```
+
+-   If provided an array-like object without a `filter` method, the function performs a linear scan and **always** returns a generic array.
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
+var isPositiveInteger = require( '@stdlib/assert/is-positive-integer' ).isPrimitive;
+var naryFunction = require( '@stdlib/utils/nary-function' );
+var filter = require( '@stdlib/array/base/filter' );
+
+var x = discreteUniform( 10, -5, 5, {
+    'dtype': 'int32'
+});
+// returns <Int32Array>
+
+var out = filter( x, naryFunction( isPositiveInteger, 1 ) );
+// returns <Int32Array>
+```
+
+</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">
+
+</section>
+
+<!-- /.links -->

base/filter/benchmark/benchmark.length.js

@@ -0,0 +1,97 @@
+/**
+* @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 isArray = require( '@stdlib/assert/is-array' );
+var isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' ).isPrimitive;
+var zeroTo = require( './../../../base/zero-to' );
+var pkg = require( './../package.json' ).name;
+var filter = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var x = zeroTo( len );
+	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 = filter( x, isNonNegativeInteger );
+			if ( typeof out !== 'object' ) {
+				b.fail( 'should return an array' );
+			}
+		}
+		b.toc();
+		if ( !isArray( out ) ) {
+			b.fail( 'should return an array' );
+		}
+		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,len='+len, f );
+	}
+}
+
+main();

base/filter/docs/repl.txt

@@ -0,0 +1,46 @@
+
+{{alias}}( x, predicate[, thisArg] )
+    Returns a shallow copy of an array containing only those elements which pass
+    a test implemented by a predicate function.
+
+    The predicate function is provided three arguments:
+
+    - value: current array element.
+    - index: current array element index.
+    - arr: the input array.
+
+    If provided an array-like object having a `filter` method , the function
+    defers execution to that method and assumes that the method has the
+    following signature:
+
+      x.filter( predicate, thisArg )
+
+    If provided an array-like object without a `filter` method, the function
+    performs a linear scan and always returns a generic array.
+
+    Parameters
+    ----------
+    x: Array|TypedArray|Object
+        Input array.
+
+    predicate: Function
+        Predicate function.
+
+    thisArg: any (optional)
+        Execution context.
+
+    Returns
+    -------
+    out: Array|TypedArray|Object
+        Output array.
+
+    Examples
+    --------
+    > function f( v ) { return ( v > 0 ); };
+    > var x = [ 1, -2, -3, 4 ];
+    > var out = {{alias}}( x, f )
+    [ 1, 4 ]
+
+    See Also
+    --------
+