Differential D4581 Diff 9612 externals/javelin/src/ext/reactor/core/Reactor.js

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externals/javelin/src/ext/reactor/core/Reactor.js

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				/**
				* @provides javelin-reactor
				* @requires javelin-install
				* javelin-util
				* @javelin
				*/

				JX.install('Reactor', {
				statics : {
				/**
				* Return this value from a ReactorNode transformer to indicate that
				* its listeners should not be activated.
				*/
				DoNotPropagate : {},
				/**
				* For internal use by the Reactor system.
				*/
				propagatePulse : function(start_pulse, start_node) {
				var reverse_post_order =
				JX.Reactor._postOrder(start_node).reverse();
				start_node.primeValue(start_pulse);

				for (var ix = 0; ix < reverse_post_order.length; ix++) {
				var node = reverse_post_order[ix];
				var pulse = node.getNextPulse();
				if (pulse === JX.Reactor.DoNotPropagate) {
				continue;
				}

				var next_pulse = node.getTransformer()(pulse);
				var sends_to = node.getListeners();
				for (var jx = 0; jx < sends_to.length; jx++) {
				sends_to[jx].primeValue(next_pulse);
				}
				}
				},
				/**
				* For internal use by the Reactor system.
				*/
				_postOrder : function(node, result, pending) {
				if (typeof result === "undefined") {
				result = [];
				pending = {};
				}
				pending[node.getGraphID()] = true;

				var nexts = node.getListeners();
				for (var ix = 0; ix < nexts.length; ix++) {
				var next = nexts[ix];
				if (pending[next.getGraphID()]) {
				continue;
				}
				JX.Reactor._postOrder(next, result, pending);
				}

				result.push(node);
				return result;
				},

				// Helper for lift.
				_valueNow : function(fn, dynvals) {
				var values = [];
				for (var ix = 0; ix < dynvals.length; ix++) {
				values.push(dynvals[ix].getValueNow());
				}
				return fn.apply(null, values);
				},

				/**
				* Lift a function over normal values to be a function over dynvals.
				* @param fn A function expecting normal values
				* @param dynvals Array of DynVals whose instaneous values will be passed
				* to fn.
				* @return A DynVal representing the changing value of fn applies to dynvals
				* over time.
				*/
				lift : function(fn, dynvals) {
				var valueNow = JX.bind(null, JX.Reactor._valueNow, fn, dynvals);

				var streams = [];
				for (var ix = 0; ix < dynvals.length; ix++) {
				streams.push(dynvals[ix].getChanges());
				}

				var result = new JX['ReactorNode'](streams, valueNow);
				return new JX['DynVal'](result, valueNow());
				}
				}
				});