24 lines
1.5 KiB
JavaScript
24 lines
1.5 KiB
JavaScript
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"use strict";
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var distinct_1 = require('./distinct');
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/**
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* Returns an Observable that emits all items emitted by the source Observable that are distinct by comparison from previous items,
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* using a property accessed by using the key provided to check if the two items are distinct.
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* If a comparator function is provided, then it will be called for each item to test for whether or not that value should be emitted.
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* If a comparator function is not provided, an equality check is used by default.
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* As the internal HashSet of this operator grows larger and larger, care should be taken in the domain of inputs this operator may see.
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* An optional paramter is also provided such that an Observable can be provided to queue the internal HashSet to flush the values it holds.
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* @param {string} key string key for object property lookup on each item.
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* @param {function} [compare] optional comparison function called to test if an item is distinct from previous items in the source.
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* @param {Observable} [flushes] optional Observable for flushing the internal HashSet of the operator.
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* @returns {Observable} an Observable that emits items from the source Observable with distinct values.
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*/
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function distinctKey(key, compare, flushes) {
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return distinct_1.distinct.call(this, function (x, y) {
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if (compare) {
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return compare(x[key], y[key]);
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}
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return x[key] === y[key];
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}, flushes);
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}
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exports.distinctKey = distinctKey;
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//# sourceMappingURL=distinctKey.js.map
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