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2.7 KiB
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1 line
2.7 KiB
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{"version":3,"file":"count.js","sourceRoot":"","sources":["../../src/operator/count.ts"],"names":[],"mappings":";AACA,sBAAqC,oBAAoB,CAAC,CAAA;AAE1D;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;GA+CG;AACH,eAA8C,SAAuE;IACnH,MAAM,CAAC,aAAW,CAAC,SAAS,CAAC,CAAC,IAAI,CAAC,CAAC;AACtC,CAAC;AAFe,aAAK,QAEpB,CAAA","sourcesContent":["import { Observable } from '../Observable';\nimport { count as higherOrder } from '../operators/count';\n\n/**\n * Counts the number of emissions on the source and emits that number when the\n * source completes.\n *\n * <span class=\"informal\">Tells how many values were emitted, when the source\n * completes.</span>\n *\n * <img src=\"./img/count.png\" width=\"100%\">\n *\n * `count` transforms an Observable that emits values into an Observable that\n * emits a single value that represents the number of values emitted by the\n * source Observable. If the source Observable terminates with an error, `count`\n * will pass this error notification along without emitting a value first. If\n * the source Observable does not terminate at all, `count` will neither emit\n * a value nor terminate. This operator takes an optional `predicate` function\n * as argument, in which case the output emission will represent the number of\n * source values that matched `true` with the `predicate`.\n *\n * @example <caption>Counts how many seconds have passed before the first click happened</caption>\n * var seconds = Rx.Observable.interval(1000);\n * var clicks = Rx.Observable.fromEvent(document, 'click');\n * var secondsBeforeClick = seconds.takeUntil(clicks);\n * var result = secondsBeforeClick.count();\n * result.subscribe(x => console.log(x));\n *\n * @example <caption>Counts how many odd numbers are there between 1 and 7</caption>\n * var numbers = Rx.Observable.range(1, 7);\n * var result = numbers.count(i => i % 2 === 1);\n * result.subscribe(x => console.log(x));\n *\n * // Results in:\n * // 4\n *\n * @see {@link max}\n * @see {@link min}\n * @see {@link reduce}\n *\n * @param {function(value: T, i: number, source: Observable<T>): boolean} [predicate] A\n * boolean function to select what values are to be counted. It is provided with\n * arguments of:\n * - `value`: the value from the source Observable.\n * - `index`: the (zero-based) \"index\" of the value from the source Observable.\n * - `source`: the source Observable instance itself.\n * @return {Observable} An Observable of one number that represents the count as\n * described above.\n * @method count\n * @owner Observable\n */\nexport function count<T>(this: Observable<T>, predicate?: (value: T, index: number, source: Observable<T>) => boolean): Observable<number> {\n return higherOrder(predicate)(this);\n}\n"]} |