65 lines
1.4 KiB
JavaScript
65 lines
1.4 KiB
JavaScript
/**
|
|
* @license Apache-2.0
|
|
*
|
|
* Copyright (c) 2018 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';
|
|
|
|
/**
|
|
* Returns an accumulator function which incrementally updates a count.
|
|
*
|
|
* @returns {Function} accumulator function
|
|
*
|
|
* @example
|
|
* var accumulator = incrcount();
|
|
*
|
|
* var count = accumulator();
|
|
* // returns 0
|
|
*
|
|
* count = accumulator( 2.0 );
|
|
* // returns 1
|
|
*
|
|
* count = accumulator( -5.0 );
|
|
* // returns 2
|
|
*
|
|
* count = accumulator();
|
|
* // returns 2
|
|
*/
|
|
function incrcount() {
|
|
var count = 0;
|
|
return accumulator;
|
|
|
|
/**
|
|
* If provided a value, the accumulator function returns an updated count. If not provided a value, the accumulator function returns the current count.
|
|
*
|
|
* @private
|
|
* @param {number} [x] - new value
|
|
* @returns {number} count
|
|
*/
|
|
function accumulator() {
|
|
if ( arguments.length === 0 ) {
|
|
return count;
|
|
}
|
|
count += 1;
|
|
return count;
|
|
}
|
|
}
|
|
|
|
|
|
// EXPORTS //
|
|
|
|
module.exports = incrcount;
|