feat: add iter/cusome-by

PR-URL: stdlib-js#2826
Closes: stdlib-js#2338

Co-authored-by: Gururaj Gurram <[email protected]>
Co-authored-by: Philipp Burckhardt <[email protected]>
Reviewed-by: Philipp Burckhardt <[email protected]>
Signed-off-by: Gururaj Gurram <[email protected]>

lib/node_modules/@stdlib/iter/cusome-by/README.md

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+<!--
+
+@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.
+
+-->
+
+# iterCuSomeBy
+
+> Create an iterator which cumulatively tests whether at least `n` iterated values 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 iterCuSomeBy = require( '@stdlib/iter/cusome-by' );
+```
+
+#### iterCuSomeBy( iterator, n, predicate\[, thisArg] )
+
+Returns an [iterator][mdn-iterator-protocol] which cumulatively tests whether at least `n` iterated values pass a test implemented by a `predicate` function.
+
+```javascript
+var array2iterator = require( '@stdlib/array/to-iterator' );
+
+function isPositive( v ) {
+    return ( v > 0 );
+}
+
+var arr = array2iterator( [ 0, 0, 0, 1, 1 ] );
+
+var it = iterCuSomeBy( arr, 2, isPositive );
+
+var v = it.next().value;
+// returns false
+
+v = it.next().value;
+// returns false
+
+v = it.next().value;
+// returns false
+
+v = it.next().value;
+// returns false
+
+v = it.next().value;
+// returns true
+
+var bool = it.next().done;
+// returns true
+```
+
+The returned [iterator][mdn-iterator-protocol] protocol-compliant object has the following properties:
+
+-   **next**: function which returns an [iterator][mdn-iterator-protocol] protocol-compliant object containing the next iterated value (if one exists) assigned to a `value` property and a `done` property having a `boolean` value indicating whether the [iterator][mdn-iterator-protocol] is finished.
+-   **return**: function which closes an [iterator][mdn-iterator-protocol] and returns a single (optional) argument in an [iterator][mdn-iterator-protocol] protocol-compliant object.
+
+A `predicate` function is provided two arguments:
+
+-   **value**: iterated value
+-   **index**: iteration index (zero-based)
+
+To set the `predicate` function execution context, provide a `thisArg`.
+
+<!-- eslint-disable no-invalid-this -->
+
+```javascript
+var array2iterator = require( '@stdlib/array/to-iterator' );
+
+function predicate( v ) {
+    this.count += 1;
+    return ( v > 0 );
+}
+
+var arr = array2iterator( [ 0, 0, 1, 1, 1 ] );
+
+var ctx = {
+    'count': 0
+};
+
+var it = iterCuSomeBy( arr, 3, predicate, ctx );
+// returns <Object>
+
+var v = it.next().value;
+// returns false
+
+v = it.next().value;
+// returns false
+
+v = it.next().value;
+// returns false
+
+v = it.next().value;
+// returns false
+
+v = it.next().value;
+// returns true
+
+var count = ctx.count;
+// returns 5
+```
+
+</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
+
+-   A `predicate` function is invoked for each iterated value until the `nth` truthy `predicate` function return value. The returned iterator continues iterating until it reaches the end of the input iterator, even after the condition is met.
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var randu = require( '@stdlib/random/iter/randu' );
+var iterCuSomeBy = require( '@stdlib/iter/cusome-by' );
+
+function threshold( r ) {
+    return ( r > 0.95 );
+}
+
+// Create an iterator which generates uniformly distributed pseudorandom numbers:
+var opts = {
+    'iter': 100
+};
+var riter = randu( opts );
+
+// Create an iterator which tracks whether at least two values have exceeded the threshold:
+var it = iterCuSomeBy( riter, 2, threshold );
+
+// Perform manual iteration...
+var r;
+while ( true ) {
+    r = it.next();
+    if ( r.done ) {
+        break;
+    }
+    console.log( r.value );
+}
+```
+
+</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">
+
+[mdn-iterator-protocol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/iter/cusome-by/benchmark/benchmark.js

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+/**
+* @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 iterConstant = require( '@stdlib/iter/constant' );
+var isIteratorLike = require( '@stdlib/assert/is-iterator-like' );
+var isBoolean = require( '@stdlib/assert/is-boolean' ).isPrimitive;
+var pkg = require( './../package.json' ).name;
+var iterCuSomeBy = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Predicate function.
+*
+* @private
+* @param {*} value - value
+* @returns {boolean} result
+*/
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var iter;
+	var it;
+	var i;
+
+	function predicate( value ) {
+		return ( value < 0 );
+	}
+
+	it = iterConstant( 3.14 );
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		iter = iterCuSomeBy( it, 2, predicate );
+		if ( typeof iter !== 'object' ) {
+			b.fail( 'should return an object' );
+		}
+	}
+	b.toc();
+	if ( !isIteratorLike( iter ) ) {
+		b.fail( 'should return an iterator protocol-compliant object' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});
+
+bench( pkg+'::iteration', function benchmark( b ) {
+	var iter;
+	var v;
+	var i;
+
+	function predicate( value ) {
+		return ( value < 0 );
+	}
+
+	iter = iterCuSomeBy( iterConstant( 3.14 ), 2, predicate );
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = iter.next().value;
+		if ( !isBoolean( v ) ) {
+			b.fail( 'should return a boolean' );
+		}
+	}
+	b.toc();
+	if ( !isBoolean( v ) ) {
+		b.fail( 'should return a boolean' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/iter/cusome-by/docs/repl.txt

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+
+{{alias}}( iterator, n, predicate[, thisArg] )
+    Returns an iterator which cumulatively tests whether at least `n` iterated
+    values pass a test implemented by a predicate function.
+
+    If an environment supports Symbol.iterator and a provided iterator is
+    iterable, the returned iterator is iterable.
+
+    The predicate function is provided two arguments:
+
+    - value: iterated value
+    - index: iteration index
+
+    A predicate function is invoked for each iterated value until the n
+    truthy predicate function return value. Upon encountering the nth truthy
+    return value, the returned iterator ceases to invoke the predicate function
+    and returns `true` for each subsequent iterated value of the provided input
+    iterator.
+
+    If provided an iterator which does not return any iterated values, the
+    function returns an iterator which is also empty.
+
+    Parameters
+    ----------
+    iterator: Object
+        Input iterator.
+
+    n: integer
+        Number of successful values to check for.
+
+    predicate: Function
+        The test function.
+
+    thisArg: any (optional)
+        Execution context.
+
+    Returns
+    -------
+    iterator: Object
+        Iterator.
+
+    iterator.next(): Function
+        Returns an iterator protocol-compliant object containing the next
+        iterated value (if one exists) and a boolean flag indicating
+        whether the iterator is finished.
+
+    iterator.return( [value] ): Function
+        Finishes an iterator and returns a provided value.
+
+    Examples
+    --------
+    > var arr = {{alias:@stdlib/array/to-iterator}}( [ 0, 0, 0, 1, 1 ] );
+    > function fcn( v ) { return ( v > 0 ); };
+    > var it = {{alias}}( arr, 2, fcn );
+    > var v = it.next().value
+    false
+    > v = it.next().value
+    false
+    > v = it.next().value
+    false
+    > v = it.next().value
+    false
+    > v = it.next().value
+    true
+
+    See Also
+    --------