"use strict";
var __extends = (this && this.__extends) || function (d, b) {
    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
    function __() { this.constructor = d; }
    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
var Subscriber_1 = require('../Subscriber');
var tryCatch_1 = require('../util/tryCatch');
var errorObject_1 = require('../util/errorObject');
/**
 * Returns an Observable that emits all items emitted by the source Observable that are distinct by comparison from the previous item.
 * 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.
 * If a comparator function is not provided, an equality check is used by default.
 * @param {function} [compare] optional comparison function called to test if an item is distinct from the previous item in the source.
 * @return {Observable} an Observable that emits items from the source Observable with distinct values.
 * @method distinctUntilChanged
 * @owner Observable
 */
function distinctUntilChanged(compare, keySelector) {
    return this.lift(new DistinctUntilChangedOperator(compare, keySelector));
}
exports.distinctUntilChanged = distinctUntilChanged;
var DistinctUntilChangedOperator = (function () {
    function DistinctUntilChangedOperator(compare, keySelector) {
        this.compare = compare;
        this.keySelector = keySelector;
    }
    DistinctUntilChangedOperator.prototype.call = function (subscriber) {
        return new DistinctUntilChangedSubscriber(subscriber, this.compare, this.keySelector);
    };
    return DistinctUntilChangedOperator;
}());
var DistinctUntilChangedSubscriber = (function (_super) {
    __extends(DistinctUntilChangedSubscriber, _super);
    function DistinctUntilChangedSubscriber(destination, compare, keySelector) {
        _super.call(this, destination);
        this.keySelector = keySelector;
        this.hasKey = false;
        if (typeof compare === 'function') {
            this.compare = compare;
        }
    }
    DistinctUntilChangedSubscriber.prototype.compare = function (x, y) {
        return x === y;
    };
    DistinctUntilChangedSubscriber.prototype._next = function (value) {
        var keySelector = this.keySelector;
        var key = value;
        if (keySelector) {
            key = tryCatch_1.tryCatch(this.keySelector)(value);
            if (key === errorObject_1.errorObject) {
                return this.destination.error(errorObject_1.errorObject.e);
            }
        }
        var result = false;
        if (this.hasKey) {
            result = tryCatch_1.tryCatch(this.compare)(this.key, key);
            if (result === errorObject_1.errorObject) {
                return this.destination.error(errorObject_1.errorObject.e);
            }
        }
        else {
            this.hasKey = true;
        }
        if (Boolean(result) === false) {
            this.key = key;
            this.destination.next(value);
        }
    };
    return DistinctUntilChangedSubscriber;
}(Subscriber_1.Subscriber));
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