The Tor Browser: comparison browser/devtools/webaudioeditor/lib/dagre-d3.js

comparison: browser/devtools/webaudioeditor/lib/dagre-d3.js

browser/devtools/webaudioeditor/lib/dagre-d3.js

changeset 0: 6474c204b198

equal deleted inserted replaced

--1:000000000000
+:2050b7f3aae5
+;(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);throw new Error("Cannot find module '"+o+"'")}var f=n[o]={exports:{}};t[o][0].call(f.exports,function(e){var n=t[o][1][e];return s(n?n:e)},f,f.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+var global=self;/**
+* @license
+* Copyright (c) 2012-2013 Chris Pettitt
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to deal
+* in the Software without restriction, including without limitation the rights
+* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+* copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+* THE SOFTWARE.
+*/
+global.dagreD3 = require('./index');
+},{"./index":2}],2:[function(require,module,exports){
+/**
+* @license
+* Copyright (c) 2012-2013 Chris Pettitt
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to deal
+* in the Software without restriction, including without limitation the rights
+* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+* copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+* THE SOFTWARE.
+*/
+module.exports =  {
+Digraph: require('graphlib').Digraph,
+Renderer: require('./lib/Renderer'),
+json: require('graphlib').converter.json,
+layout: require('dagre').layout,
+version: require('./lib/version')
+};
+},{"./lib/Renderer":3,"./lib/version":4,"dagre":11,"graphlib":28}],3:[function(require,module,exports){
+var layout = require('dagre').layout;
+var d3;
+try { d3 = require('d3'); } catch (_) { d3 = window.d3; }
+module.exports = Renderer;
+function Renderer() {
+// Set up defaults...
+this._layout = layout();
+this.drawNodes(defaultDrawNodes);
+this.drawEdgeLabels(defaultDrawEdgeLabels);
+this.drawEdgePaths(defaultDrawEdgePaths);
+this.positionNodes(defaultPositionNodes);
+this.positionEdgeLabels(defaultPositionEdgeLabels);
+this.positionEdgePaths(defaultPositionEdgePaths);
+this.transition(defaultTransition);
+this.postLayout(defaultPostLayout);
+this.postRender(defaultPostRender);
+this.edgeInterpolate('bundle');
+this.edgeTension(0.95);
+}
+Renderer.prototype.layout = function(layout) {
+if (!arguments.length) { return this._layout; }
+this._layout = layout;
+return this;
+};
+Renderer.prototype.drawNodes = function(drawNodes) {
+if (!arguments.length) { return this._drawNodes; }
+this._drawNodes = bind(drawNodes, this);
+return this;
+};
+Renderer.prototype.drawEdgeLabels = function(drawEdgeLabels) {
+if (!arguments.length) { return this._drawEdgeLabels; }
+this._drawEdgeLabels = bind(drawEdgeLabels, this);
+return this;
+};
+Renderer.prototype.drawEdgePaths = function(drawEdgePaths) {
+if (!arguments.length) { return this._drawEdgePaths; }
+this._drawEdgePaths = bind(drawEdgePaths, this);
+return this;
+};
+Renderer.prototype.positionNodes = function(positionNodes) {
+if (!arguments.length) { return this._positionNodes; }
+this._positionNodes = bind(positionNodes, this);
+return this;
+};
+Renderer.prototype.positionEdgeLabels = function(positionEdgeLabels) {
+if (!arguments.length) { return this._positionEdgeLabels; }
+this._positionEdgeLabels = bind(positionEdgeLabels, this);
+return this;
+};
+Renderer.prototype.positionEdgePaths = function(positionEdgePaths) {
+if (!arguments.length) { return this._positionEdgePaths; }
+this._positionEdgePaths = bind(positionEdgePaths, this);
+return this;
+};
+Renderer.prototype.transition = function(transition) {
+if (!arguments.length) { return this._transition; }
+this._transition = bind(transition, this);
+return this;
+};
+Renderer.prototype.postLayout = function(postLayout) {
+if (!arguments.length) { return this._postLayout; }
+this._postLayout = bind(postLayout, this);
+return this;
+};
+Renderer.prototype.postRender = function(postRender) {
+if (!arguments.length) { return this._postRender; }
+this._postRender = bind(postRender, this);
+return this;
+};
+Renderer.prototype.edgeInterpolate = function(edgeInterpolate) {
+if (!arguments.length) { return this._edgeInterpolate; }
+this._edgeInterpolate = edgeInterpolate;
+return this;
+};
+Renderer.prototype.edgeTension = function(edgeTension) {
+if (!arguments.length) { return this._edgeTension; }
+this._edgeTension = edgeTension;
+return this;
+};
+Renderer.prototype.run = function(graph, svg) {
+// First copy the input graph so that it is not changed by the rendering
+// process.
+graph = copyAndInitGraph(graph);
+// Create layers
+svg
+.selectAll('g.edgePaths, g.edgeLabels, g.nodes')
+.data(['edgePaths', 'edgeLabels', 'nodes'])
+.enter()
+.append('g')
+.attr('class', function(d) { return d; });
+// Create node and edge roots, attach labels, and capture dimension
+// information for use with layout.
+var svgNodes = this._drawNodes(graph, svg.select('g.nodes'));
+var svgEdgeLabels = this._drawEdgeLabels(graph, svg.select('g.edgeLabels'));
+svgNodes.each(function(u) { calculateDimensions(this, graph.node(u)); });
+svgEdgeLabels.each(function(e) { calculateDimensions(this, graph.edge(e)); });
+// Now apply the layout function
+var result = runLayout(graph, this._layout);
+// Run any user-specified post layout processing
+this._postLayout(result, svg);
+var svgEdgePaths = this._drawEdgePaths(graph, svg.select('g.edgePaths'));
+// Apply the layout information to the graph
+this._positionNodes(result, svgNodes);
+this._positionEdgeLabels(result, svgEdgeLabels);
+this._positionEdgePaths(result, svgEdgePaths);
+this._postRender(result, svg);
+return result;
+};
+function copyAndInitGraph(graph) {
+var copy = graph.copy();
+// Init labels if they were not present in the source graph
+copy.nodes().forEach(function(u) {
+var value = copy.node(u);
+if (value === undefined) {
+value = {};
+copy.node(u, value);
+}
+if (!('label' in value)) { value.label = ''; }
+});
+copy.edges().forEach(function(e) {
+var value = copy.edge(e);
+if (value === undefined) {
+value = {};
+copy.edge(e, value);
+}
+if (!('label' in value)) { value.label = ''; }
+});
+return copy;
+}
+function calculateDimensions(group, value) {
+var bbox = group.getBBox();
+value.width = bbox.width;
+value.height = bbox.height;
+}
+function runLayout(graph, layout) {
+var result = layout.run(graph);
+// Copy labels to the result graph
+graph.eachNode(function(u, value) { result.node(u).label = value.label; });
+graph.eachEdge(function(e, u, v, value) { result.edge(e).label = value.label; });
+return result;
+}
+function defaultDrawNodes(g, root) {
+var nodes = g.nodes().filter(function(u) { return !isComposite(g, u); });
+var svgNodes = root
+.selectAll('g.node')
+.classed('enter', false)
+.data(nodes, function(u) { return u; });
+svgNodes.selectAll('*').remove();
+svgNodes
+.enter()
+.append('g')
+.style('opacity', 0)
+.attr('class', 'node enter');
+svgNodes.each(function(u) { addLabel(g.node(u), d3.select(this), 10, 10); });
+this._transition(svgNodes.exit())
+.style('opacity', 0)
+.remove();
+return svgNodes;
+}
+function defaultDrawEdgeLabels(g, root) {
+var svgEdgeLabels = root
+.selectAll('g.edgeLabel')
+.classed('enter', false)
+.data(g.edges(), function (e) { return e; });
+svgEdgeLabels.selectAll('*').remove();
+svgEdgeLabels
+.enter()
+.append('g')
+.style('opacity', 0)
+.attr('class', 'edgeLabel enter');
+svgEdgeLabels.each(function(e) { addLabel(g.edge(e), d3.select(this), 0, 0); });
+this._transition(svgEdgeLabels.exit())
+.style('opacity', 0)
+.remove();
+return svgEdgeLabels;
+}
+var defaultDrawEdgePaths = function(g, root) {
+var svgEdgePaths = root
+.selectAll('g.edgePath')
+.classed('enter', false)
+.data(g.edges(), function(e) { return e; });
+svgEdgePaths
+.enter()
+.append('g')
+.attr('class', 'edgePath enter')
+.append('path')
+.style('opacity', 0)
+.attr('marker-end', 'url(#arrowhead)');
+this._transition(svgEdgePaths.exit())
+.style('opacity', 0)
+.remove();
+return svgEdgePaths;
+};
+function defaultPositionNodes(g, svgNodes, svgNodesEnter) {
+function transform(u) {
+var value = g.node(u);
+return 'translate(' + value.x + ',' + value.y + ')';
+}
+// For entering nodes, position immediately without transition
+svgNodes.filter('.enter').attr('transform', transform);
+this._transition(svgNodes)
+.style('opacity', 1)
+.attr('transform', transform);
+}
+function defaultPositionEdgeLabels(g, svgEdgeLabels) {
+function transform(e) {
+var value = g.edge(e);
+var point = findMidPoint(value.points);
+return 'translate(' + point.x + ',' + point.y + ')';
+}
+// For entering edge labels, position immediately without transition
+svgEdgeLabels.filter('.enter').attr('transform', transform);
+this._transition(svgEdgeLabels)
+.style('opacity', 1)
+.attr('transform', transform);
+}
+function defaultPositionEdgePaths(g, svgEdgePaths) {
+var interpolate = this._edgeInterpolate,
+tension = this._edgeTension;
+function calcPoints(e) {
+var value = g.edge(e);
+var source = g.node(g.incidentNodes(e)[0]);
+var target = g.node(g.incidentNodes(e)[1]);
+var points = value.points.slice();
+var p0 = points.length === 0 ? target : points[0];
+var p1 = points.length === 0 ? source : points[points.length - 1];
+points.unshift(intersectRect(source, p0));
+// TODO: use bpodgursky's shortening algorithm here
+points.push(intersectRect(target, p1));
+return d3.svg.line()
+.x(function(d) { return d.x; })
+.y(function(d) { return d.y; })
+.interpolate(interpolate)
+.tension(tension)
+(points);
+}
+svgEdgePaths.filter('.enter').selectAll('path')
+.attr('d', calcPoints);
+this._transition(svgEdgePaths.selectAll('path'))
+.attr('d', calcPoints)
+.style('opacity', 1);
+}
+// By default we do not use transitions
+function defaultTransition(selection) {
+return selection;
+}
+function defaultPostLayout() {
+// Do nothing
+}
+function defaultPostRender(graph, root) {
+if (graph.isDirected() && root.select('#arrowhead').empty()) {
+root
+.append('svg:defs')
+.append('svg:marker')
+.attr('id', 'arrowhead')
+.attr('viewBox', '0 0 10 10')
+.attr('refX', 8)
+.attr('refY', 5)
+.attr('markerUnits', 'strokewidth')
+.attr('markerWidth', 8)
+.attr('markerHeight', 5)
+.attr('orient', 'auto')
+.attr('style', 'fill: #333')
+.append('svg:path')
+.attr('d', 'M 0 0 L 10 5 L 0 10 z');
+}
+}
+function addLabel(node, root, marginX, marginY) {
+// Add the rect first so that it appears behind the label
+var label = node.label;
+var rect = root.append('rect');
+var labelSvg = root.append('g');
+if (label[0] === '<') {
+addForeignObjectLabel(label, labelSvg);
+// No margin for HTML elements
+marginX = marginY = 0;
+} else {
+addTextLabel(label,
+labelSvg,
+Math.floor(node.labelCols),
+node.labelCut);
+}
+var bbox = root.node().getBBox();
+labelSvg.attr('transform',
+'translate(' + (-bbox.width / 2) + ',' + (-bbox.height / 2) + ')');
+rect
+.attr('rx', 5)
+.attr('ry', 5)
+.attr('x', -(bbox.width / 2 + marginX))
+.attr('y', -(bbox.height / 2 + marginY))
+.attr('width', bbox.width + 2 * marginX)
+.attr('height', bbox.height + 2 * marginY);
+}
+function addForeignObjectLabel(label, root) {
+var fo = root
+.append('foreignObject')
+.attr('width', '100000');
+var w, h;
+fo
+.append('xhtml:div')
+.style('float', 'left')
+// TODO find a better way to get dimensions for foreignObjects...
+.html(function() { return label; })
+.each(function() {
+w = this.clientWidth;
+h = this.clientHeight;
+});
+fo
+.attr('width', w)
+.attr('height', h);
+}
+function addTextLabel(label, root, labelCols, labelCut) {
+if (labelCut === undefined) labelCut = "false";
+labelCut = (labelCut.toString().toLowerCase() === "true");
+var node = root
+.append('text')
+.attr('text-anchor', 'left');
+label = label.replace(/\\n/g, "\n");
+var arr = labelCols ? wordwrap(label, labelCols, labelCut) : label;
+arr = arr.split("\n");
+for (var i = 0; i < arr.length; i++) {
+node
+.append('tspan')
+.attr('dy', '1em')
+.attr('x', '1')
+.text(arr[i]);
+}
+}
+// Thanks to
+// http://james.padolsey.com/javascript/wordwrap-for-javascript/
+function wordwrap (str, width, cut, brk) {
+brk = brk || '\n';
+width = width || 75;
+cut = cut || false;
+if (!str) { return str; }
+var regex = '.{1,' +width+ '}(\\s|$)' + (cut ? '|.{' +width+ '}|.+$' : '|\\S+?(\\s|$)');
+return str.match( RegExp(regex, 'g') ).join( brk );
+}
+function findMidPoint(points) {
+var midIdx = points.length / 2;
+if (points.length % 2) {
+return points[Math.floor(midIdx)];
+} else {
+var p0 = points[midIdx - 1];
+var p1 = points[midIdx];
+return {x: (p0.x + p1.x) / 2, y: (p0.y + p1.y) / 2};
+}
+}
+function intersectRect(rect, point) {
+var x = rect.x;
+var y = rect.y;
+// For now we only support rectangles
+// Rectangle intersection algorithm from:
+// http://math.stackexchange.com/questions/108113/find-edge-between-two-boxes
+var dx = point.x - x;
+var dy = point.y - y;
+var w = rect.width / 2;
+var h = rect.height / 2;
+var sx, sy;
+if (Math.abs(dy) * w > Math.abs(dx) * h) {
+// Intersection is top or bottom of rect.
+if (dy < 0) {
+h = -h;
+}
+sx = dy === 0 ? 0 : h * dx / dy;
+sy = h;
+} else {
+// Intersection is left or right of rect.
+if (dx < 0) {
+w = -w;
+}
+sx = w;
+sy = dx === 0 ? 0 : w * dy / dx;
+}
+return {x: x + sx, y: y + sy};
+}
+function isComposite(g, u) {
+return 'children' in g && g.children(u).length;
+}
+function bind(func, thisArg) {
+// For some reason PhantomJS occassionally fails when using the builtin bind,
+// so we check if it is available and if not, use a degenerate polyfill.
+if (func.bind) {
+return func.bind(thisArg);
+}
+return function() {
+return func.apply(thisArg, arguments);
+};
+}
+},{"d3":10,"dagre":11}],4:[function(require,module,exports){
+module.exports = '0.1.5';
+},{}],5:[function(require,module,exports){
+exports.Set = require('./lib/Set');
+exports.PriorityQueue = require('./lib/PriorityQueue');
+exports.version = require('./lib/version');
+},{"./lib/PriorityQueue":6,"./lib/Set":7,"./lib/version":9}],6:[function(require,module,exports){
+module.exports = PriorityQueue;
+/**
+* A min-priority queue data structure. This algorithm is derived from Cormen,
+* et al., "Introduction to Algorithms". The basic idea of a min-priority
+* queue is that you can efficiently (in O(1) time) get the smallest key in
+* the queue. Adding and removing elements takes O(log n) time. A key can
+* have its priority decreased in O(log n) time.
+*/
+function PriorityQueue() {
+this._arr = [];
+this._keyIndices = {};
+}
+/**
+* Returns the number of elements in the queue. Takes `O(1)` time.
+*/
+PriorityQueue.prototype.size = function() {
+return this._arr.length;
+};
+/**
+* Returns the keys that are in the queue. Takes `O(n)` time.
+*/
+PriorityQueue.prototype.keys = function() {
+return this._arr.map(function(x) { return x.key; });
+};
+/**
+* Returns `true` if **key** is in the queue and `false` if not.
+*/
+PriorityQueue.prototype.has = function(key) {
+return key in this._keyIndices;
+};
+/**
+* Returns the priority for **key**. If **key** is not present in the queue
+* then this function returns `undefined`. Takes `O(1)` time.
+*
+* @param {Object} key
+*/
+PriorityQueue.prototype.priority = function(key) {
+var index = this._keyIndices[key];
+if (index !== undefined) {
+return this._arr[index].priority;
+}
+};
+/**
+* Returns the key for the minimum element in this queue. If the queue is
+* empty this function throws an Error. Takes `O(1)` time.
+*/
+PriorityQueue.prototype.min = function() {
+if (this.size() === 0) {
+throw new Error("Queue underflow");
+}
+return this._arr[0].key;
+};
+/**
+* Inserts a new key into the priority queue. If the key already exists in
+* the queue this function returns `false`; otherwise it will return `true`.
+* Takes `O(n)` time.
+*
+* @param {Object} key the key to add
+* @param {Number} priority the initial priority for the key
+*/
+PriorityQueue.prototype.add = function(key, priority) {
+var keyIndices = this._keyIndices;
+if (!(key in keyIndices)) {
+var arr = this._arr;
+var index = arr.length;
+keyIndices[key] = index;
+arr.push({key: key, priority: priority});
+this._decrease(index);
+return true;
+}
+return false;
+};
+/**
+* Removes and returns the smallest key in the queue. Takes `O(log n)` time.
+*/
+PriorityQueue.prototype.removeMin = function() {
+this._swap(0, this._arr.length - 1);
+var min = this._arr.pop();
+delete this._keyIndices[min.key];
+this._heapify(0);
+return min.key;
+};
+/**
+* Decreases the priority for **key** to **priority**. If the new priority is
+* greater than the previous priority, this function will throw an Error.
+*
+* @param {Object} key the key for which to raise priority
+* @param {Number} priority the new priority for the key
+*/
+PriorityQueue.prototype.decrease = function(key, priority) {
+var index = this._keyIndices[key];
+if (priority > this._arr[index].priority) {
+throw new Error("New priority is greater than current priority. " +
+"Key: " + key + " Old: " + this._arr[index].priority + " New: " + priority);
+}
+this._arr[index].priority = priority;
+this._decrease(index);
+};
+PriorityQueue.prototype._heapify = function(i) {
+var arr = this._arr;
+var l = 2 * i,
+r = l + 1,
+largest = i;
+if (l < arr.length) {
+largest = arr[l].priority < arr[largest].priority ? l : largest;
+if (r < arr.length) {
+largest = arr[r].priority < arr[largest].priority ? r : largest;
+}
+if (largest !== i) {
+this._swap(i, largest);
+this._heapify(largest);
+}
+}
+};
+PriorityQueue.prototype._decrease = function(index) {
+var arr = this._arr;
+var priority = arr[index].priority;
+var parent;
+while (index !== 0) {
+parent = index >> 1;
+if (arr[parent].priority < priority) {
+break;
+}
+this._swap(index, parent);
+index = parent;
+}
+};
+PriorityQueue.prototype._swap = function(i, j) {
+var arr = this._arr;
+var keyIndices = this._keyIndices;
+var origArrI = arr[i];
+var origArrJ = arr[j];
+arr[i] = origArrJ;
+arr[j] = origArrI;
+keyIndices[origArrJ.key] = i;
+keyIndices[origArrI.key] = j;
+};
+},{}],7:[function(require,module,exports){
+var util = require('./util');
+module.exports = Set;
+/**
+* Constructs a new Set with an optional set of `initialKeys`.
+*
+* It is important to note that keys are coerced to String for most purposes
+* with this object, similar to the behavior of JavaScript's Object. For
+* example, the following will add only one key:
+*
+*     var s = new Set();
+*     s.add(1);
+*     s.add("1");
+*
+* However, the type of the key is preserved internally so that `keys` returns
+* the original key set uncoerced. For the above example, `keys` would return
+* `[1]`.
+*/
+function Set(initialKeys) {
+this._size = 0;
+this._keys = {};
+if (initialKeys) {
+for (var i = 0, il = initialKeys.length; i < il; ++i) {
+this.add(initialKeys[i]);
+}
+}
+}
+/**
+* Returns a new Set that represents the set intersection of the array of given
+* sets.
+*/
+Set.intersect = function(sets) {
+if (sets.length === 0) {
+return new Set();
+}
+var result = new Set(!util.isArray(sets[0]) ? sets[0].keys() : sets[0]);
+for (var i = 1, il = sets.length; i < il; ++i) {
+var resultKeys = result.keys(),
+other = !util.isArray(sets[i]) ? sets[i] : new Set(sets[i]);
+for (var j = 0, jl = resultKeys.length; j < jl; ++j) {
+var key = resultKeys[j];
+if (!other.has(key)) {
+result.remove(key);
+}
+}
+}
+return result;
+};
+/**
+* Returns a new Set that represents the set union of the array of given sets.
+*/
+Set.union = function(sets) {
+var totalElems = util.reduce(sets, function(lhs, rhs) {
+return lhs + (rhs.size ? rhs.size() : rhs.length);
+}, 0);
+var arr = new Array(totalElems);
+var k = 0;
+for (var i = 0, il = sets.length; i < il; ++i) {
+var cur = sets[i],
+keys = !util.isArray(cur) ? cur.keys() : cur;
+for (var j = 0, jl = keys.length; j < jl; ++j) {
+arr[k++] = keys[j];
+}
+}
+return new Set(arr);
+};
+/**
+* Returns the size of this set in `O(1)` time.
+*/
+Set.prototype.size = function() {
+return this._size;
+};
+/**
+* Returns the keys in this set. Takes `O(n)` time.
+*/
+Set.prototype.keys = function() {
+return values(this._keys);
+};
+/**
+* Tests if a key is present in this Set. Returns `true` if it is and `false`
+* if not. Takes `O(1)` time.
+*/
+Set.prototype.has = function(key) {
+return key in this._keys;
+};
+/**
+* Adds a new key to this Set if it is not already present. Returns `true` if
+* the key was added and `false` if it was already present. Takes `O(1)` time.
+*/
+Set.prototype.add = function(key) {
+if (!(key in this._keys)) {
+this._keys[key] = key;
+++this._size;
+return true;
+}
+return false;
+};
+/**
+* Removes a key from this Set. If the key was removed this function returns
+* `true`. If not, it returns `false`. Takes `O(1)` time.
+*/
+Set.prototype.remove = function(key) {
+if (key in this._keys) {
+delete this._keys[key];
+--this._size;
+return true;
+}
+return false;
+};
+/*
+* Returns an array of all values for properties of **o**.
+*/
+function values(o) {
+var ks = Object.keys(o),
+len = ks.length,
+result = new Array(len),
+i;
+for (i = 0; i < len; ++i) {
+result[i] = o[ks[i]];
+}
+return result;
+}
+},{"./util":8}],8:[function(require,module,exports){
+/*
+* This polyfill comes from
+* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray
+*/
+if(!Array.isArray) {
+exports.isArray = function (vArg) {
+return Object.prototype.toString.call(vArg) === '[object Array]';
+};
+} else {
+exports.isArray = Array.isArray;
+}
+/*
+* Slightly adapted polyfill from
+* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce
+*/
+if ('function' !== typeof Array.prototype.reduce) {
+exports.reduce = function(array, callback, opt_initialValue) {
+'use strict';
+if (null === array || 'undefined' === typeof array) {
+// At the moment all modern browsers, that support strict mode, have
+// native implementation of Array.prototype.reduce. For instance, IE8
+// does not support strict mode, so this check is actually useless.
+throw new TypeError(
+'Array.prototype.reduce called on null or undefined');
+}
+if ('function' !== typeof callback) {
+throw new TypeError(callback + ' is not a function');
+}
+var index, value,
+length = array.length >>> 0,
+isValueSet = false;
+if (1 < arguments.length) {
+value = opt_initialValue;
+isValueSet = true;
+}
+for (index = 0; length > index; ++index) {
+if (array.hasOwnProperty(index)) {
+if (isValueSet) {
+value = callback(value, array[index], index, array);
+}
+else {
+value = array[index];
+isValueSet = true;
+}
+}
+}
+if (!isValueSet) {
+throw new TypeError('Reduce of empty array with no initial value');
+}
+return value;
+};
+} else {
+exports.reduce = function(array, callback, opt_initialValue) {
+return array.reduce(callback, opt_initialValue);
+};
+}
+},{}],9:[function(require,module,exports){
+module.exports = '1.1.3';
+},{}],10:[function(require,module,exports){
+require("./d3");
+module.exports = d3;
+(function () { delete this.d3; })(); // unset global
+},{}],11:[function(require,module,exports){
+/*
+Copyright (c) 2012-2013 Chris Pettitt
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+exports.Digraph = require("graphlib").Digraph;
+exports.Graph = require("graphlib").Graph;
+exports.layout = require("./lib/layout");
+exports.version = require("./lib/version");
+},{"./lib/layout":12,"./lib/version":27,"graphlib":28}],12:[function(require,module,exports){
+var util = require('./util'),
+rank = require('./rank'),
+order = require('./order'),
+CGraph = require('graphlib').CGraph,
+CDigraph = require('graphlib').CDigraph;
+module.exports = function() {
+// External configuration
+var config = {
+// How much debug information to include?
+debugLevel: 0,
+// Max number of sweeps to perform in order phase
+orderMaxSweeps: order.DEFAULT_MAX_SWEEPS,
+// Use network simplex algorithm in ranking
+rankSimplex: false,
+// Rank direction. Valid values are (TB, LR)
+rankDir: 'TB'
+};
+// Phase functions
+var position = require('./position')();
+// This layout object
+var self = {};
+self.orderIters = util.propertyAccessor(self, config, 'orderMaxSweeps');
+self.rankSimplex = util.propertyAccessor(self, config, 'rankSimplex');
+self.nodeSep = delegateProperty(position.nodeSep);
+self.edgeSep = delegateProperty(position.edgeSep);
+self.universalSep = delegateProperty(position.universalSep);
+self.rankSep = delegateProperty(position.rankSep);
+self.rankDir = util.propertyAccessor(self, config, 'rankDir');
+self.debugAlignment = delegateProperty(position.debugAlignment);
+self.debugLevel = util.propertyAccessor(self, config, 'debugLevel', function(x) {
+util.log.level = x;
+position.debugLevel(x);
+});
+self.run = util.time('Total layout', run);
+self._normalize = normalize;
+return self;
+/*
+* Constructs an adjacency graph using the nodes and edges specified through
+* config. For each node and edge we add a property `dagre` that contains an
+* object that will hold intermediate and final layout information. Some of
+* the contents include:
+*
+*  1) A generated ID that uniquely identifies the object.
+*  2) Dimension information for nodes (copied from the source node).
+*  3) Optional dimension information for edges.
+*
+* After the adjacency graph is constructed the code no longer needs to use
+* the original nodes and edges passed in via config.
+*/
+function initLayoutGraph(inputGraph) {
+var g = new CDigraph();
+inputGraph.eachNode(function(u, value) {
+if (value === undefined) value = {};
+g.addNode(u, {
+width: value.width,
+height: value.height
+});
+if (value.hasOwnProperty('rank')) {
+g.node(u).prefRank = value.rank;
+}
+});
+// Set up subgraphs
+if (inputGraph.parent) {
+inputGraph.nodes().forEach(function(u) {
+g.parent(u, inputGraph.parent(u));
+});
+}
+inputGraph.eachEdge(function(e, u, v, value) {
+if (value === undefined) value = {};
+var newValue = {
+e: e,
+minLen: value.minLen || 1,
+width: value.width || 0,
+height: value.height || 0,
+points: []
+};
+g.addEdge(null, u, v, newValue);
+});
+// Initial graph attributes
+var graphValue = inputGraph.graph() || {};
+g.graph({
+rankDir: graphValue.rankDir || config.rankDir,
+orderRestarts: graphValue.orderRestarts
+});
+return g;
+}
+function run(inputGraph) {
+var rankSep = self.rankSep();
+var g;
+try {
+// Build internal graph
+g = util.time('initLayoutGraph', initLayoutGraph)(inputGraph);
+if (g.order() === 0) {
+return g;
+}
+// Make space for edge labels
+g.eachEdge(function(e, s, t, a) {
+a.minLen *= 2;
+});
+self.rankSep(rankSep / 2);
+// Determine the rank for each node. Nodes with a lower rank will appear
+// above nodes of higher rank.
+util.time('rank.run', rank.run)(g, config.rankSimplex);
+// Normalize the graph by ensuring that every edge is proper (each edge has
+// a length of 1). We achieve this by adding dummy nodes to long edges,
+// thus shortening them.
+util.time('normalize', normalize)(g);
+// Order the nodes so that edge crossings are minimized.
+util.time('order', order)(g, config.orderMaxSweeps);
+// Find the x and y coordinates for every node in the graph.
+util.time('position', position.run)(g);
+// De-normalize the graph by removing dummy nodes and augmenting the
+// original long edges with coordinate information.
+util.time('undoNormalize', undoNormalize)(g);
+// Reverses points for edges that are in a reversed state.
+util.time('fixupEdgePoints', fixupEdgePoints)(g);
+// Restore delete edges and reverse edges that were reversed in the rank
+// phase.
+util.time('rank.restoreEdges', rank.restoreEdges)(g);
+// Construct final result graph and return it
+return util.time('createFinalGraph', createFinalGraph)(g, inputGraph.isDirected());
+} finally {
+self.rankSep(rankSep);
+}
+}
+/*
+* This function is responsible for 'normalizing' the graph. The process of
+* normalization ensures that no edge in the graph has spans more than one
+* rank. To do this it inserts dummy nodes as needed and links them by adding
+* dummy edges. This function keeps enough information in the dummy nodes and
+* edges to ensure that the original graph can be reconstructed later.
+*
+* This method assumes that the input graph is cycle free.
+*/
+function normalize(g) {
+var dummyCount = 0;
+g.eachEdge(function(e, s, t, a) {
+var sourceRank = g.node(s).rank;
+var targetRank = g.node(t).rank;
+if (sourceRank + 1 < targetRank) {
+for (var u = s, rank = sourceRank + 1, i = 0; rank < targetRank; ++rank, ++i) {
+var v = '_D' + (++dummyCount);
+var node = {
+width: a.width,
+height: a.height,
+edge: { id: e, source: s, target: t, attrs: a },
+rank: rank,
+dummy: true
+};
+// If this node represents a bend then we will use it as a control
+// point. For edges with 2 segments this will be the center dummy
+// node. For edges with more than two segments, this will be the
+// first and last dummy node.
+if (i === 0) node.index = 0;
+else if (rank + 1 === targetRank) node.index = 1;
+g.addNode(v, node);
+g.addEdge(null, u, v, {});
+u = v;
+}
+g.addEdge(null, u, t, {});
+g.delEdge(e);
+}
+});
+}
+/*
+* Reconstructs the graph as it was before normalization. The positions of
+* dummy nodes are used to build an array of points for the original 'long'
+* edge. Dummy nodes and edges are removed.
+*/
+function undoNormalize(g) {
+g.eachNode(function(u, a) {
+if (a.dummy) {
+if ('index' in a) {
+var edge = a.edge;
+if (!g.hasEdge(edge.id)) {
+g.addEdge(edge.id, edge.source, edge.target, edge.attrs);
+}
+var points = g.edge(edge.id).points;
+points[a.index] = { x: a.x, y: a.y, ul: a.ul, ur: a.ur, dl: a.dl, dr: a.dr };
+}
+g.delNode(u);
+}
+});
+}
+/*
+* For each edge that was reversed during the `acyclic` step, reverse its
+* array of points.
+*/
+function fixupEdgePoints(g) {
+g.eachEdge(function(e, s, t, a) { if (a.reversed) a.points.reverse(); });
+}
+function createFinalGraph(g, isDirected) {
+var out = isDirected ? new CDigraph() : new CGraph();
+out.graph(g.graph());
+g.eachNode(function(u, value) { out.addNode(u, value); });
+g.eachNode(function(u) { out.parent(u, g.parent(u)); });
+g.eachEdge(function(e, u, v, value) {
+out.addEdge(value.e, u, v, value);
+});
+// Attach bounding box information
+var maxX = 0, maxY = 0;
+g.eachNode(function(u, value) {
+if (!g.children(u).length) {
+maxX = Math.max(maxX, value.x + value.width / 2);
+maxY = Math.max(maxY, value.y + value.height / 2);
+}
+});
+g.eachEdge(function(e, u, v, value) {
+var maxXPoints = Math.max.apply(Math, value.points.map(function(p) { return p.x; }));
+var maxYPoints = Math.max.apply(Math, value.points.map(function(p) { return p.y; }));
+maxX = Math.max(maxX, maxXPoints + value.width / 2);
+maxY = Math.max(maxY, maxYPoints + value.height / 2);
+});
+out.graph().width = maxX;
+out.graph().height = maxY;
+return out;
+}
+/*
+* Given a function, a new function is returned that invokes the given
+* function. The return value from the function is always the `self` object.
+*/
+function delegateProperty(f) {
+return function() {
+if (!arguments.length) return f();
+f.apply(null, arguments);
+return self;
+};
+}
+};
+},{"./order":13,"./position":18,"./rank":19,"./util":26,"graphlib":28}],13:[function(require,module,exports){
+var util = require('./util'),
+crossCount = require('./order/crossCount'),
+initLayerGraphs = require('./order/initLayerGraphs'),
+initOrder = require('./order/initOrder'),
+sortLayer = require('./order/sortLayer');
+module.exports = order;
+// The maximum number of sweeps to perform before finishing the order phase.
+var DEFAULT_MAX_SWEEPS = 24;
+order.DEFAULT_MAX_SWEEPS = DEFAULT_MAX_SWEEPS;
+/*
+* Runs the order phase with the specified `graph, `maxSweeps`, and
+* `debugLevel`. If `maxSweeps` is not specified we use `DEFAULT_MAX_SWEEPS`.
+* If `debugLevel` is not set we assume 0.
+*/
+function order(g, maxSweeps) {
+if (arguments.length < 2) {
+maxSweeps = DEFAULT_MAX_SWEEPS;
+}
+var restarts = g.graph().orderRestarts || 0;
+var layerGraphs = initLayerGraphs(g);
+// TODO: remove this when we add back support for ordering clusters
+layerGraphs.forEach(function(lg) {
+lg = lg.filterNodes(function(u) { return !g.children(u).length; });
+});
+var iters = 0,
+currentBestCC,
+allTimeBestCC = Number.MAX_VALUE,
+allTimeBest = {};
+function saveAllTimeBest() {
+g.eachNode(function(u, value) { allTimeBest[u] = value.order; });
+}
+for (var j = 0; j < Number(restarts) + 1 && allTimeBestCC !== 0; ++j) {
+currentBestCC = Number.MAX_VALUE;
+initOrder(g, restarts > 0);
+util.log(2, 'Order phase start cross count: ' + g.graph().orderInitCC);
+var i, lastBest, cc;
+for (i = 0, lastBest = 0; lastBest < 4 && i < maxSweeps && currentBestCC > 0; ++i, ++lastBest, ++iters) {
+sweep(g, layerGraphs, i);
+cc = crossCount(g);
+if (cc < currentBestCC) {
+lastBest = 0;
+currentBestCC = cc;
+if (cc < allTimeBestCC) {
+saveAllTimeBest();
+allTimeBestCC = cc;
+}
+}
+util.log(3, 'Order phase start ' + j + ' iter ' + i + ' cross count: ' + cc);
+}
+}
+Object.keys(allTimeBest).forEach(function(u) {
+if (!g.children || !g.children(u).length) {
+g.node(u).order = allTimeBest[u];
+}
+});
+g.graph().orderCC = allTimeBestCC;
+util.log(2, 'Order iterations: ' + iters);
+util.log(2, 'Order phase best cross count: ' + g.graph().orderCC);
+}
+function predecessorWeights(g, nodes) {
+var weights = {};
+nodes.forEach(function(u) {
+weights[u] = g.inEdges(u).map(function(e) {
+return g.node(g.source(e)).order;
+});
+});
+return weights;
+}
+function successorWeights(g, nodes) {
+var weights = {};
+nodes.forEach(function(u) {
+weights[u] = g.outEdges(u).map(function(e) {
+return g.node(g.target(e)).order;
+});
+});
+return weights;
+}
+function sweep(g, layerGraphs, iter) {
+if (iter % 2 === 0) {
+sweepDown(g, layerGraphs, iter);
+} else {
+sweepUp(g, layerGraphs, iter);
+}
+}
+function sweepDown(g, layerGraphs) {
+var cg;
+for (i = 1; i < layerGraphs.length; ++i) {
+cg = sortLayer(layerGraphs[i], cg, predecessorWeights(g, layerGraphs[i].nodes()));
+}
+}
+function sweepUp(g, layerGraphs) {
+var cg;
+for (i = layerGraphs.length - 2; i >= 0; --i) {
+sortLayer(layerGraphs[i], cg, successorWeights(g, layerGraphs[i].nodes()));
+}
+}
+},{"./order/crossCount":14,"./order/initLayerGraphs":15,"./order/initOrder":16,"./order/sortLayer":17,"./util":26}],14:[function(require,module,exports){
+var util = require('../util');
+module.exports = crossCount;
+/*
+* Returns the cross count for the given graph.
+*/
+function crossCount(g) {
+var cc = 0;
+var ordering = util.ordering(g);
+for (var i = 1; i < ordering.length; ++i) {
+cc += twoLayerCrossCount(g, ordering[i-1], ordering[i]);
+}
+return cc;
+}
+/*
+* This function searches through a ranked and ordered graph and counts the
+* number of edges that cross. This algorithm is derived from:
+*
+*    W. Barth et al., Bilayer Cross Counting, JGAA, 8(2) 179–194 (2004)
+*/
+function twoLayerCrossCount(g, layer1, layer2) {
+var indices = [];
+layer1.forEach(function(u) {
+var nodeIndices = [];
+g.outEdges(u).forEach(function(e) { nodeIndices.push(g.node(g.target(e)).order); });
+nodeIndices.sort(function(x, y) { return x - y; });
+indices = indices.concat(nodeIndices);
+});
+var firstIndex = 1;
+while (firstIndex < layer2.length) firstIndex <<= 1;
+var treeSize = 2 * firstIndex - 1;
+firstIndex -= 1;
+var tree = [];
+for (var i = 0; i < treeSize; ++i) { tree[i] = 0; }
+var cc = 0;
+indices.forEach(function(i) {
+var treeIndex = i + firstIndex;
+++tree[treeIndex];
+while (treeIndex > 0) {
+if (treeIndex % 2) {
+cc += tree[treeIndex + 1];
+}
+treeIndex = (treeIndex - 1) >> 1;
+++tree[treeIndex];
+}
+});
+return cc;
+}
+},{"../util":26}],15:[function(require,module,exports){
+var nodesFromList = require('graphlib').filter.nodesFromList,
+/* jshint -W079 */
+Set = require('cp-data').Set;
+module.exports = initLayerGraphs;
+/*
+* This function takes a compound layered graph, g, and produces an array of
+* layer graphs. Each entry in the array represents a subgraph of nodes
+* relevant for performing crossing reduction on that layer.
+*/
+function initLayerGraphs(g) {
+var ranks = [];
+function dfs(u) {
+if (u === null) {
+g.children(u).forEach(function(v) { dfs(v); });
+return;
+}
+var value = g.node(u);
+value.minRank = ('rank' in value) ? value.rank : Number.MAX_VALUE;
+value.maxRank = ('rank' in value) ? value.rank : Number.MIN_VALUE;
+var uRanks = new Set();
+g.children(u).forEach(function(v) {
+var rs = dfs(v);
+uRanks = Set.union([uRanks, rs]);
+value.minRank = Math.min(value.minRank, g.node(v).minRank);
+value.maxRank = Math.max(value.maxRank, g.node(v).maxRank);
+});
+if ('rank' in value) uRanks.add(value.rank);
+uRanks.keys().forEach(function(r) {
+if (!(r in ranks)) ranks[r] = [];
+ranks[r].push(u);
+});
+return uRanks;
+}
+dfs(null);
+var layerGraphs = [];
+ranks.forEach(function(us, rank) {
+layerGraphs[rank] = g.filterNodes(nodesFromList(us));
+});
+return layerGraphs;
+}
+},{"cp-data":5,"graphlib":28}],16:[function(require,module,exports){
+var crossCount = require('./crossCount'),
+util = require('../util');
+module.exports = initOrder;
+/*
+* Given a graph with a set of layered nodes (i.e. nodes that have a `rank`
+* attribute) this function attaches an `order` attribute that uniquely
+* arranges each node of each rank. If no constraint graph is provided the
+* order of the nodes in each rank is entirely arbitrary.
+*/
+function initOrder(g, random) {
+var layers = [];
+g.eachNode(function(u, value) {
+var layer = layers[value.rank];
+if (g.children && g.children(u).length > 0) return;
+if (!layer) {
+layer = layers[value.rank] = [];
+}
+layer.push(u);
+});
+layers.forEach(function(layer) {
+if (random) {
+util.shuffle(layer);
+}
+layer.forEach(function(u, i) {
+g.node(u).order = i;
+});
+});
+var cc = crossCount(g);
+g.graph().orderInitCC = cc;
+g.graph().orderCC = Number.MAX_VALUE;
+}
+},{"../util":26,"./crossCount":14}],17:[function(require,module,exports){
+var util = require('../util');
+/*
+Digraph = require('graphlib').Digraph,
+topsort = require('graphlib').alg.topsort,
+nodesFromList = require('graphlib').filter.nodesFromList;
+*/
+module.exports = sortLayer;
+/*
+function sortLayer(g, cg, weights) {
+var result = sortLayerSubgraph(g, null, cg, weights);
+result.list.forEach(function(u, i) {
+g.node(u).order = i;
+});
+return result.constraintGraph;
+}
+*/
+function sortLayer(g, cg, weights) {
+var ordering = [];
+var bs = {};
+g.eachNode(function(u, value) {
+ordering[value.order] = u;
+var ws = weights[u];
+if (ws.length) {
+bs[u] = util.sum(ws) / ws.length;
+}
+});
+var toSort = g.nodes().filter(function(u) { return bs[u] !== undefined; });
+toSort.sort(function(x, y) {
+return bs[x] - bs[y] || g.node(x).order - g.node(y).order;
+});
+for (var i = 0, j = 0, jl = toSort.length; j < jl; ++i) {
+if (bs[ordering[i]] !== undefined) {
+g.node(toSort[j++]).order = i;
+}
+}
+}
+// TOOD: re-enable constrained sorting once we have a strategy for handling
+// undefined barycenters.
+/*
+function sortLayerSubgraph(g, sg, cg, weights) {
+cg = cg ? cg.filterNodes(nodesFromList(g.children(sg))) : new Digraph();
+var nodeData = {};
+g.children(sg).forEach(function(u) {
+if (g.children(u).length) {
+nodeData[u] = sortLayerSubgraph(g, u, cg, weights);
+nodeData[u].firstSG = u;
+nodeData[u].lastSG = u;
+} else {
+var ws = weights[u];
+nodeData[u] = {
+degree: ws.length,
+barycenter: ws.length > 0 ? util.sum(ws) / ws.length : 0,
+list: [u]
+};
+}
+});
+resolveViolatedConstraints(g, cg, nodeData);
+var keys = Object.keys(nodeData);
+keys.sort(function(x, y) {
+return nodeData[x].barycenter - nodeData[y].barycenter;
+});
+var result =  keys.map(function(u) { return nodeData[u]; })
+.reduce(function(lhs, rhs) { return mergeNodeData(g, lhs, rhs); });
+return result;
+}
+/*
+function mergeNodeData(g, lhs, rhs) {
+var cg = mergeDigraphs(lhs.constraintGraph, rhs.constraintGraph);
+if (lhs.lastSG !== undefined && rhs.firstSG !== undefined) {
+if (cg === undefined) {
+cg = new Digraph();
+}
+if (!cg.hasNode(lhs.lastSG)) { cg.addNode(lhs.lastSG); }
+cg.addNode(rhs.firstSG);
+cg.addEdge(null, lhs.lastSG, rhs.firstSG);
+}
+return {
+degree: lhs.degree + rhs.degree,
+barycenter: (lhs.barycenter * lhs.degree + rhs.barycenter * rhs.degree) /
+(lhs.degree + rhs.degree),
+list: lhs.list.concat(rhs.list),
+firstSG: lhs.firstSG !== undefined ? lhs.firstSG : rhs.firstSG,
+lastSG: rhs.lastSG !== undefined ? rhs.lastSG : lhs.lastSG,
+constraintGraph: cg
+};
+}
+function mergeDigraphs(lhs, rhs) {
+if (lhs === undefined) return rhs;
+if (rhs === undefined) return lhs;
+lhs = lhs.copy();
+rhs.nodes().forEach(function(u) { lhs.addNode(u); });
+rhs.edges().forEach(function(e, u, v) { lhs.addEdge(null, u, v); });
+return lhs;
+}
+function resolveViolatedConstraints(g, cg, nodeData) {
+// Removes nodes `u` and `v` from `cg` and makes any edges incident on them
+// incident on `w` instead.
+function collapseNodes(u, v, w) {
+// TODO original paper removes self loops, but it is not obvious when this would happen
+cg.inEdges(u).forEach(function(e) {
+cg.delEdge(e);
+cg.addEdge(null, cg.source(e), w);
+});
+cg.outEdges(v).forEach(function(e) {
+cg.delEdge(e);
+cg.addEdge(null, w, cg.target(e));
+});
+cg.delNode(u);
+cg.delNode(v);
+}
+var violated;
+while ((violated = findViolatedConstraint(cg, nodeData)) !== undefined) {
+var source = cg.source(violated),
+target = cg.target(violated);
+var v;
+while ((v = cg.addNode(null)) && g.hasNode(v)) {
+cg.delNode(v);
+}
+// Collapse barycenter and list
+nodeData[v] = mergeNodeData(g, nodeData[source], nodeData[target]);
+delete nodeData[source];
+delete nodeData[target];
+collapseNodes(source, target, v);
+if (cg.incidentEdges(v).length === 0) { cg.delNode(v); }
+}
+}
+function findViolatedConstraint(cg, nodeData) {
+var us = topsort(cg);
+for (var i = 0; i < us.length; ++i) {
+var u = us[i];
+var inEdges = cg.inEdges(u);
+for (var j = 0; j < inEdges.length; ++j) {
+var e = inEdges[j];
+if (nodeData[cg.source(e)].barycenter >= nodeData[u].barycenter) {
+return e;
+}
+}
+}
+}
+*/
+},{"../util":26}],18:[function(require,module,exports){
+var util = require('./util');
+/*
+* The algorithms here are based on Brandes and Köpf, "Fast and Simple
+* Horizontal Coordinate Assignment".
+*/
+module.exports = function() {
+// External configuration
+var config = {
+nodeSep: 50,
+edgeSep: 10,
+universalSep: null,
+rankSep: 30
+};
+var self = {};
+self.nodeSep = util.propertyAccessor(self, config, 'nodeSep');
+self.edgeSep = util.propertyAccessor(self, config, 'edgeSep');
+// If not null this separation value is used for all nodes and edges
+// regardless of their widths. `nodeSep` and `edgeSep` are ignored with this
+// option.
+self.universalSep = util.propertyAccessor(self, config, 'universalSep');
+self.rankSep = util.propertyAccessor(self, config, 'rankSep');
+self.debugLevel = util.propertyAccessor(self, config, 'debugLevel');
+self.run = run;
+return self;
+function run(g) {
+g = g.filterNodes(util.filterNonSubgraphs(g));
+var layering = util.ordering(g);
+var conflicts = findConflicts(g, layering);
+var xss = {};
+['u', 'd'].forEach(function(vertDir) {
+if (vertDir === 'd') layering.reverse();
+['l', 'r'].forEach(function(horizDir) {
+if (horizDir === 'r') reverseInnerOrder(layering);
+var dir = vertDir + horizDir;
+var align = verticalAlignment(g, layering, conflicts, vertDir === 'u' ? 'predecessors' : 'successors');
+xss[dir]= horizontalCompaction(g, layering, align.pos, align.root, align.align);
+if (config.debugLevel >= 3)
+debugPositioning(vertDir + horizDir, g, layering, xss[dir]);
+if (horizDir === 'r') flipHorizontally(xss[dir]);
+if (horizDir === 'r') reverseInnerOrder(layering);
+});
+if (vertDir === 'd') layering.reverse();
+});
+balance(g, layering, xss);
+g.eachNode(function(v) {
+var xs = [];
+for (var alignment in xss) {
+var alignmentX = xss[alignment][v];
+posXDebug(alignment, g, v, alignmentX);
+xs.push(alignmentX);
+}
+xs.sort(function(x, y) { return x - y; });
+posX(g, v, (xs[1] + xs[2]) / 2);
+});
+// Align y coordinates with ranks
+var y = 0, reverseY = g.graph().rankDir === 'BT' || g.graph().rankDir === 'RL';
+layering.forEach(function(layer) {
+var maxHeight = util.max(layer.map(function(u) { return height(g, u); }));
+y += maxHeight / 2;
+layer.forEach(function(u) {
+posY(g, u, reverseY ? -y : y);
+});
+y += maxHeight / 2 + config.rankSep;
+});
+// Translate layout so that top left corner of bounding rectangle has
+// coordinate (0, 0).
+var minX = util.min(g.nodes().map(function(u) { return posX(g, u) - width(g, u) / 2; }));
+var minY = util.min(g.nodes().map(function(u) { return posY(g, u) - height(g, u) / 2; }));
+g.eachNode(function(u) {
+posX(g, u, posX(g, u) - minX);
+posY(g, u, posY(g, u) - minY);
+});
+}
+/*
+* Generate an ID that can be used to represent any undirected edge that is
+* incident on `u` and `v`.
+*/
+function undirEdgeId(u, v) {
+return u < v
+? u.toString().length + ':' + u + '-' + v
+: v.toString().length + ':' + v + '-' + u;
+}
+function findConflicts(g, layering) {
+var conflicts = {}, // Set of conflicting edge ids
+pos = {},       // Position of node in its layer
+prevLayer,
+currLayer,
+k0,     // Position of the last inner segment in the previous layer
+l,      // Current position in the current layer (for iteration up to `l1`)
+k1;     // Position of the next inner segment in the previous layer or
+// the position of the last element in the previous layer
+if (layering.length <= 2) return conflicts;
+function updateConflicts(v) {
+var k = pos[v];
+if (k < k0 || k > k1) {
+conflicts[undirEdgeId(currLayer[l], v)] = true;
+}
+}
+layering[1].forEach(function(u, i) { pos[u] = i; });
+for (var i = 1; i < layering.length - 1; ++i) {
+prevLayer = layering[i];
+currLayer = layering[i+1];
+k0 = 0;
+l = 0;
+// Scan current layer for next node that is incident to an inner segement
+// between layering[i+1] and layering[i].
+for (var l1 = 0; l1 < currLayer.length; ++l1) {
+var u = currLayer[l1]; // Next inner segment in the current layer or
+// last node in the current layer
+pos[u] = l1;
+k1 = undefined;
+if (g.node(u).dummy) {
+var uPred = g.predecessors(u)[0];
+// Note: In the case of self loops and sideways edges it is possible
+// for a dummy not to have a predecessor.
+if (uPred !== undefined && g.node(uPred).dummy)
+k1 = pos[uPred];
+}
+if (k1 === undefined && l1 === currLayer.length - 1)
+k1 = prevLayer.length - 1;
+if (k1 !== undefined) {
+for (; l <= l1; ++l) {
+g.predecessors(currLayer[l]).forEach(updateConflicts);
+}
+k0 = k1;
+}
+}
+}
+return conflicts;
+}
+function verticalAlignment(g, layering, conflicts, relationship) {
+var pos = {},   // Position for a node in its layer
+root = {},  // Root of the block that the node participates in
+align = {}; // Points to the next node in the block or, if the last
+// element in the block, points to the first block's root
+layering.forEach(function(layer) {
+layer.forEach(function(u, i) {
+root[u] = u;
+align[u] = u;
+pos[u] = i;
+});
+});
+layering.forEach(function(layer) {
+var prevIdx = -1;
+layer.forEach(function(v) {
+var related = g[relationship](v), // Adjacent nodes from the previous layer
+mid;                          // The mid point in the related array
+if (related.length > 0) {
+related.sort(function(x, y) { return pos[x] - pos[y]; });
+mid = (related.length - 1) / 2;
+related.slice(Math.floor(mid), Math.ceil(mid) + 1).forEach(function(u) {
+if (align[v] === v) {
+if (!conflicts[undirEdgeId(u, v)] && prevIdx < pos[u]) {
+align[u] = v;
+align[v] = root[v] = root[u];
+prevIdx = pos[u];
+}
+}
+});
+}
+});
+});
+return { pos: pos, root: root, align: align };
+}
+// This function deviates from the standard BK algorithm in two ways. First
+// it takes into account the size of the nodes. Second it includes a fix to
+// the original algorithm that is described in Carstens, "Node and Label
+// Placement in a Layered Layout Algorithm".
+function horizontalCompaction(g, layering, pos, root, align) {
+var sink = {},       // Mapping of node id -> sink node id for class
+maybeShift = {}, // Mapping of sink node id -> { class node id, min shift }
+shift = {},      // Mapping of sink node id -> shift
+pred = {},       // Mapping of node id -> predecessor node (or null)
+xs = {};         // Calculated X positions
+layering.forEach(function(layer) {
+layer.forEach(function(u, i) {
+sink[u] = u;
+maybeShift[u] = {};
+if (i > 0)
+pred[u] = layer[i - 1];
+});
+});
+function updateShift(toShift, neighbor, delta) {
+if (!(neighbor in maybeShift[toShift])) {
+maybeShift[toShift][neighbor] = delta;
+} else {
+maybeShift[toShift][neighbor] = Math.min(maybeShift[toShift][neighbor], delta);
+}
+}
+function placeBlock(v) {
+if (!(v in xs)) {
+xs[v] = 0;
+var w = v;
+do {
+if (pos[w] > 0) {
+var u = root[pred[w]];
+placeBlock(u);
+if (sink[v] === v) {
+sink[v] = sink[u];
+}
+var delta = sep(g, pred[w]) + sep(g, w);
+if (sink[v] !== sink[u]) {
+updateShift(sink[u], sink[v], xs[v] - xs[u] - delta);
+} else {
+xs[v] = Math.max(xs[v], xs[u] + delta);
+}
+}
+w = align[w];
+} while (w !== v);
+}
+}
+// Root coordinates relative to sink
+util.values(root).forEach(function(v) {
+placeBlock(v);
+});
+// Absolute coordinates
+// There is an assumption here that we've resolved shifts for any classes
+// that begin at an earlier layer. We guarantee this by visiting layers in
+// order.
+layering.forEach(function(layer) {
+layer.forEach(function(v) {
+xs[v] = xs[root[v]];
+if (v === root[v] && v === sink[v]) {
+var minShift = 0;
+if (v in maybeShift && Object.keys(maybeShift[v]).length > 0) {
+minShift = util.min(Object.keys(maybeShift[v])
+.map(function(u) {
+return maybeShift[v][u] + (u in shift ? shift[u] : 0);
+}
+));
+}
+shift[v] = minShift;
+}
+});
+});
+layering.forEach(function(layer) {
+layer.forEach(function(v) {
+xs[v] += shift[sink[root[v]]] || 0;
+});
+});
+return xs;
+}
+function findMinCoord(g, layering, xs) {
+return util.min(layering.map(function(layer) {
+var u = layer[0];
+return xs[u];
+}));
+}
+function findMaxCoord(g, layering, xs) {
+return util.max(layering.map(function(layer) {
+var u = layer[layer.length - 1];
+return xs[u];
+}));
+}
+function balance(g, layering, xss) {
+var min = {},                            // Min coordinate for the alignment
+max = {},                            // Max coordinate for the alginment
+smallestAlignment,
+shift = {};                          // Amount to shift a given alignment
+function updateAlignment(v) {
+xss[alignment][v] += shift[alignment];
+}
+var smallest = Number.POSITIVE_INFINITY;
+for (var alignment in xss) {
+var xs = xss[alignment];
+min[alignment] = findMinCoord(g, layering, xs);
+max[alignment] = findMaxCoord(g, layering, xs);
+var w = max[alignment] - min[alignment];
+if (w < smallest) {
+smallest = w;
+smallestAlignment = alignment;
+}
+}
+// Determine how much to adjust positioning for each alignment
+['u', 'd'].forEach(function(vertDir) {
+['l', 'r'].forEach(function(horizDir) {
+var alignment = vertDir + horizDir;
+shift[alignment] = horizDir === 'l'
+? min[smallestAlignment] - min[alignment]
+: max[smallestAlignment] - max[alignment];
+});
+});
+// Find average of medians for xss array
+for (alignment in xss) {
+g.eachNode(updateAlignment);
+}
+}
+function flipHorizontally(xs) {
+for (var u in xs) {
+xs[u] = -xs[u];
+}
+}
+function reverseInnerOrder(layering) {
+layering.forEach(function(layer) {
+layer.reverse();
+});
+}
+function width(g, u) {
+switch (g.graph().rankDir) {
+case 'LR': return g.node(u).height;
+case 'RL': return g.node(u).height;
+default:   return g.node(u).width;
+}
+}
+function height(g, u) {
+switch(g.graph().rankDir) {
+case 'LR': return g.node(u).width;
+case 'RL': return g.node(u).width;
+default:   return g.node(u).height;
+}
+}
+function sep(g, u) {
+if (config.universalSep !== null) {
+return config.universalSep;
+}
+var w = width(g, u);
+var s = g.node(u).dummy ? config.edgeSep : config.nodeSep;
+return (w + s) / 2;
+}
+function posX(g, u, x) {
+if (g.graph().rankDir === 'LR' || g.graph().rankDir === 'RL') {
+if (arguments.length < 3) {
+return g.node(u).y;
+} else {
+g.node(u).y = x;
+}
+} else {
+if (arguments.length < 3) {
+return g.node(u).x;
+} else {
+g.node(u).x = x;
+}
+}
+}
+function posXDebug(name, g, u, x) {
+if (g.graph().rankDir === 'LR' || g.graph().rankDir === 'RL') {
+if (arguments.length < 3) {
+return g.node(u)[name];
+} else {
+g.node(u)[name] = x;
+}
+} else {
+if (arguments.length < 3) {
+return g.node(u)[name];
+} else {
+g.node(u)[name] = x;
+}
+}
+}
+function posY(g, u, y) {
+if (g.graph().rankDir === 'LR' || g.graph().rankDir === 'RL') {
+if (arguments.length < 3) {
+return g.node(u).x;
+} else {
+g.node(u).x = y;
+}
+} else {
+if (arguments.length < 3) {
+return g.node(u).y;
+} else {
+g.node(u).y = y;
+}
+}
+}
+function debugPositioning(align, g, layering, xs) {
+layering.forEach(function(l, li) {
+var u, xU;
+l.forEach(function(v) {
+var xV = xs[v];
+if (u) {
+var s = sep(g, u) + sep(g, v);
+if (xV - xU < s)
+console.log('Position phase: sep violation. Align: ' + align + '. Layer: ' + li + '. ' +
+'U: ' + u + ' V: ' + v + '. Actual sep: ' + (xV - xU) + ' Expected sep: ' + s);
+}
+u = v;
+xU = xV;
+});
+});
+}
+};
+},{"./util":26}],19:[function(require,module,exports){
+var util = require('./util'),
+acyclic = require('./rank/acyclic'),
+initRank = require('./rank/initRank'),
+feasibleTree = require('./rank/feasibleTree'),
+constraints = require('./rank/constraints'),
+simplex = require('./rank/simplex'),
+components = require('graphlib').alg.components,
+filter = require('graphlib').filter;
+exports.run = run;
+exports.restoreEdges = restoreEdges;
+/*
+* Heuristic function that assigns a rank to each node of the input graph with
+* the intent of minimizing edge lengths, while respecting the `minLen`
+* attribute of incident edges.
+*
+* Prerequisites:
+*
+*  * Each edge in the input graph must have an assigned 'minLen' attribute
+*/
+function run(g, useSimplex) {
+expandSelfLoops(g);
+// If there are rank constraints on nodes, then build a new graph that
+// encodes the constraints.
+util.time('constraints.apply', constraints.apply)(g);
+expandSidewaysEdges(g);
+// Reverse edges to get an acyclic graph, we keep the graph in an acyclic
+// state until the very end.
+util.time('acyclic', acyclic)(g);
+// Convert the graph into a flat graph for ranking
+var flatGraph = g.filterNodes(util.filterNonSubgraphs(g));
+// Assign an initial ranking using DFS.
+initRank(flatGraph);
+// For each component improve the assigned ranks.
+components(flatGraph).forEach(function(cmpt) {
+var subgraph = flatGraph.filterNodes(filter.nodesFromList(cmpt));
+rankComponent(subgraph, useSimplex);
+});
+// Relax original constraints
+util.time('constraints.relax', constraints.relax(g));
+// When handling nodes with constrained ranks it is possible to end up with
+// edges that point to previous ranks. Most of the subsequent algorithms assume
+// that edges are pointing to successive ranks only. Here we reverse any "back
+// edges" and mark them as such. The acyclic algorithm will reverse them as a
+// post processing step.
+util.time('reorientEdges', reorientEdges)(g);
+}
+function restoreEdges(g) {
+acyclic.undo(g);
+}
+/*
+* Expand self loops into three dummy nodes. One will sit above the incident
+* node, one will be at the same level, and one below. The result looks like:
+*
+*         /--<--x--->--\
+*     node              y
+*         \--<--z--->--/
+*
+* Dummy nodes x, y, z give us the shape of a loop and node y is where we place
+* the label.
+*
+* TODO: consolidate knowledge of dummy node construction.
+* TODO: support minLen = 2
+*/
+function expandSelfLoops(g) {
+g.eachEdge(function(e, u, v, a) {
+if (u === v) {
+var x = addDummyNode(g, e, u, v, a, 0, false),
+y = addDummyNode(g, e, u, v, a, 1, true),
+z = addDummyNode(g, e, u, v, a, 2, false);
+g.addEdge(null, x, u, {minLen: 1, selfLoop: true});
+g.addEdge(null, x, y, {minLen: 1, selfLoop: true});
+g.addEdge(null, u, z, {minLen: 1, selfLoop: true});
+g.addEdge(null, y, z, {minLen: 1, selfLoop: true});
+g.delEdge(e);
+}
+});
+}
+function expandSidewaysEdges(g) {
+g.eachEdge(function(e, u, v, a) {
+if (u === v) {
+var origEdge = a.originalEdge,
+dummy = addDummyNode(g, origEdge.e, origEdge.u, origEdge.v, origEdge.value, 0, true);
+g.addEdge(null, u, dummy, {minLen: 1});
+g.addEdge(null, dummy, v, {minLen: 1});
+g.delEdge(e);
+}
+});
+}
+function addDummyNode(g, e, u, v, a, index, isLabel) {
+return g.addNode(null, {
+width: isLabel ? a.width : 0,
+height: isLabel ? a.height : 0,
+edge: { id: e, source: u, target: v, attrs: a },
+dummy: true,
+index: index
+});
+}
+function reorientEdges(g) {
+g.eachEdge(function(e, u, v, value) {
+if (g.node(u).rank > g.node(v).rank) {
+g.delEdge(e);
+value.reversed = true;
+g.addEdge(e, v, u, value);
+}
+});
+}
+function rankComponent(subgraph, useSimplex) {
+var spanningTree = feasibleTree(subgraph);
+if (useSimplex) {
+util.log(1, 'Using network simplex for ranking');
+simplex(subgraph, spanningTree);
+}
+normalize(subgraph);
+}
+function normalize(g) {
+var m = util.min(g.nodes().map(function(u) { return g.node(u).rank; }));
+g.eachNode(function(u, node) { node.rank -= m; });
+}
+},{"./rank/acyclic":20,"./rank/constraints":21,"./rank/feasibleTree":22,"./rank/initRank":23,"./rank/simplex":25,"./util":26,"graphlib":28}],20:[function(require,module,exports){
+var util = require('../util');
+module.exports = acyclic;
+module.exports.undo = undo;
+/*
+* This function takes a directed graph that may have cycles and reverses edges
+* as appropriate to break these cycles. Each reversed edge is assigned a
+* `reversed` attribute with the value `true`.
+*
+* There should be no self loops in the graph.
+*/
+function acyclic(g) {
+var onStack = {},
+visited = {},
+reverseCount = 0;
+function dfs(u) {
+if (u in visited) return;
+visited[u] = onStack[u] = true;
+g.outEdges(u).forEach(function(e) {
+var t = g.target(e),
+value;
+if (u === t) {
+console.error('Warning: found self loop "' + e + '" for node "' + u + '"');
+} else if (t in onStack) {
+value = g.edge(e);
+g.delEdge(e);
+value.reversed = true;
+++reverseCount;
+g.addEdge(e, t, u, value);
+} else {
+dfs(t);
+}
+});
+delete onStack[u];
+}
+g.eachNode(function(u) { dfs(u); });
+util.log(2, 'Acyclic Phase: reversed ' + reverseCount + ' edge(s)');
+return reverseCount;
+}
+/*
+* Given a graph that has had the acyclic operation applied, this function
+* undoes that operation. More specifically, any edge with the `reversed`
+* attribute is again reversed to restore the original direction of the edge.
+*/
+function undo(g) {
+g.eachEdge(function(e, s, t, a) {
+if (a.reversed) {
+delete a.reversed;
+g.delEdge(e);
+g.addEdge(e, t, s, a);
+}
+});
+}
+},{"../util":26}],21:[function(require,module,exports){
+exports.apply = function(g) {
+function dfs(sg) {
+var rankSets = {};
+g.children(sg).forEach(function(u) {
+if (g.children(u).length) {
+dfs(u);
+return;
+}
+var value = g.node(u),
+prefRank = value.prefRank;
+if (prefRank !== undefined) {
+if (!checkSupportedPrefRank(prefRank)) { return; }
+if (!(prefRank in rankSets)) {
+rankSets.prefRank = [u];
+} else {
+rankSets.prefRank.push(u);
+}
+var newU = rankSets[prefRank];
+if (newU === undefined) {
+newU = rankSets[prefRank] = g.addNode(null, { originalNodes: [] });
+g.parent(newU, sg);
+}
+redirectInEdges(g, u, newU, prefRank === 'min');
+redirectOutEdges(g, u, newU, prefRank === 'max');
+// Save original node and remove it from reduced graph
+g.node(newU).originalNodes.push({ u: u, value: value, parent: sg });
+g.delNode(u);
+}
+});
+addLightEdgesFromMinNode(g, sg, rankSets.min);
+addLightEdgesToMaxNode(g, sg, rankSets.max);
+}
+dfs(null);
+};
+function checkSupportedPrefRank(prefRank) {
+if (prefRank !== 'min' && prefRank !== 'max' && prefRank.indexOf('same_') !== 0) {
+console.error('Unsupported rank type: ' + prefRank);
+return false;
+}
+return true;
+}
+function redirectInEdges(g, u, newU, reverse) {
+g.inEdges(u).forEach(function(e) {
+var origValue = g.edge(e),
+value;
+if (origValue.originalEdge) {
+value = origValue;
+} else {
+value =  {
+originalEdge: { e: e, u: g.source(e), v: g.target(e), value: origValue },
+minLen: g.edge(e).minLen
+};
+}
+// Do not reverse edges for self-loops.
+if (origValue.selfLoop) {
+reverse = false;
+}
+if (reverse) {
+// Ensure that all edges to min are reversed
+g.addEdge(null, newU, g.source(e), value);
+value.reversed = true;
+} else {
+g.addEdge(null, g.source(e), newU, value);
+}
+});
+}
+function redirectOutEdges(g, u, newU, reverse) {
+g.outEdges(u).forEach(function(e) {
+var origValue = g.edge(e),
+value;
+if (origValue.originalEdge) {
+value = origValue;
+} else {
+value =  {
+originalEdge: { e: e, u: g.source(e), v: g.target(e), value: origValue },
+minLen: g.edge(e).minLen
+};
+}
+// Do not reverse edges for self-loops.
+if (origValue.selfLoop) {
+reverse = false;
+}
+if (reverse) {
+// Ensure that all edges from max are reversed
+g.addEdge(null, g.target(e), newU, value);
+value.reversed = true;
+} else {
+g.addEdge(null, newU, g.target(e), value);
+}
+});
+}
+function addLightEdgesFromMinNode(g, sg, minNode) {
+if (minNode !== undefined) {
+g.children(sg).forEach(function(u) {
+// The dummy check ensures we don't add an edge if the node is involved
+// in a self loop or sideways edge.
+if (u !== minNode && !g.outEdges(minNode, u).length && !g.node(u).dummy) {
+g.addEdge(null, minNode, u, { minLen: 0 });
+}
+});
+}
+}
+function addLightEdgesToMaxNode(g, sg, maxNode) {
+if (maxNode !== undefined) {
+g.children(sg).forEach(function(u) {
+// The dummy check ensures we don't add an edge if the node is involved
+// in a self loop or sideways edge.
+if (u !== maxNode && !g.outEdges(u, maxNode).length && !g.node(u).dummy) {
+g.addEdge(null, u, maxNode, { minLen: 0 });
+}
+});
+}
+}
+/*
+* This function "relaxes" the constraints applied previously by the "apply"
+* function. It expands any nodes that were collapsed and assigns the rank of
+* the collapsed node to each of the expanded nodes. It also restores the
+* original edges and removes any dummy edges pointing at the collapsed nodes.
+*
+* Note that the process of removing collapsed nodes also removes dummy edges
+* automatically.
+*/
+exports.relax = function(g) {
+// Save original edges
+var originalEdges = [];
+g.eachEdge(function(e, u, v, value) {
+var originalEdge = value.originalEdge;
+if (originalEdge) {
+originalEdges.push(originalEdge);
+}
+});
+// Expand collapsed nodes
+g.eachNode(function(u, value) {
+var originalNodes = value.originalNodes;
+if (originalNodes) {
+originalNodes.forEach(function(originalNode) {
+originalNode.value.rank = value.rank;
+g.addNode(originalNode.u, originalNode.value);
+g.parent(originalNode.u, originalNode.parent);
+});
+g.delNode(u);
+}
+});
+// Restore original edges
+originalEdges.forEach(function(edge) {
+g.addEdge(edge.e, edge.u, edge.v, edge.value);
+});
+};
+},{}],22:[function(require,module,exports){
+/* jshint -W079 */
+var Set = require('cp-data').Set,
+/* jshint +W079 */
+Digraph = require('graphlib').Digraph,
+util = require('../util');
+module.exports = feasibleTree;
+/*
+* Given an acyclic graph with each node assigned a `rank` attribute, this
+* function constructs and returns a spanning tree. This function may reduce
+* the length of some edges from the initial rank assignment while maintaining
+* the `minLen` specified by each edge.
+*
+* Prerequisites:
+*
+* * The input graph is acyclic
+* * Each node in the input graph has an assigned `rank` attribute
+* * Each edge in the input graph has an assigned `minLen` attribute
+*
+* Outputs:
+*
+* A feasible spanning tree for the input graph (i.e. a spanning tree that
+* respects each graph edge's `minLen` attribute) represented as a Digraph with
+* a `root` attribute on graph.
+*
+* Nodes have the same id and value as that in the input graph.
+*
+* Edges in the tree have arbitrarily assigned ids. The attributes for edges
+* include `reversed`. `reversed` indicates that the edge is a
+* back edge in the input graph.
+*/
+function feasibleTree(g) {
+var remaining = new Set(g.nodes()),
+tree = new Digraph();
+if (remaining.size() === 1) {
+var root = g.nodes()[0];
+tree.addNode(root, {});
+tree.graph({ root: root });
+return tree;
+}
+function addTightEdges(v) {
+var continueToScan = true;
+g.predecessors(v).forEach(function(u) {
+if (remaining.has(u) && !slack(g, u, v)) {
+if (remaining.has(v)) {
+tree.addNode(v, {});
+remaining.remove(v);
+tree.graph({ root: v });
+}
+tree.addNode(u, {});
+tree.addEdge(null, u, v, { reversed: true });
+remaining.remove(u);
+addTightEdges(u);
+continueToScan = false;
+}
+});
+g.successors(v).forEach(function(w)  {
+if (remaining.has(w) && !slack(g, v, w)) {
+if (remaining.has(v)) {
+tree.addNode(v, {});
+remaining.remove(v);
+tree.graph({ root: v });
+}
+tree.addNode(w, {});
+tree.addEdge(null, v, w, {});
+remaining.remove(w);
+addTightEdges(w);
+continueToScan = false;
+}
+});
+return continueToScan;
+}
+function createTightEdge() {
+var minSlack = Number.MAX_VALUE;
+remaining.keys().forEach(function(v) {
+g.predecessors(v).forEach(function(u) {
+if (!remaining.has(u)) {
+var edgeSlack = slack(g, u, v);
+if (Math.abs(edgeSlack) < Math.abs(minSlack)) {
+minSlack = -edgeSlack;
+}
+}
+});
+g.successors(v).forEach(function(w) {
+if (!remaining.has(w)) {
+var edgeSlack = slack(g, v, w);
+if (Math.abs(edgeSlack) < Math.abs(minSlack)) {
+minSlack = edgeSlack;
+}
+}
+});
+});
+tree.eachNode(function(u) { g.node(u).rank -= minSlack; });
+}
+while (remaining.size()) {
+var nodesToSearch = !tree.order() ? remaining.keys() : tree.nodes();
+for (var i = 0, il = nodesToSearch.length;
+i < il && addTightEdges(nodesToSearch[i]);
+++i);
+if (remaining.size()) {
+createTightEdge();
+}
+}
+return tree;
+}
+function slack(g, u, v) {
+var rankDiff = g.node(v).rank - g.node(u).rank;
+var maxMinLen = util.max(g.outEdges(u, v)
+.map(function(e) { return g.edge(e).minLen; }));
+return rankDiff - maxMinLen;
+}
+},{"../util":26,"cp-data":5,"graphlib":28}],23:[function(require,module,exports){
+var util = require('../util'),
+topsort = require('graphlib').alg.topsort;
+module.exports = initRank;
+/*
+* Assigns a `rank` attribute to each node in the input graph and ensures that
+* this rank respects the `minLen` attribute of incident edges.
+*
+* Prerequisites:
+*
+*  * The input graph must be acyclic
+*  * Each edge in the input graph must have an assigned 'minLen' attribute
+*/
+function initRank(g) {
+var sorted = topsort(g);
+sorted.forEach(function(u) {
+var inEdges = g.inEdges(u);
+if (inEdges.length === 0) {
+g.node(u).rank = 0;
+return;
+}
+var minLens = inEdges.map(function(e) {
+return g.node(g.source(e)).rank + g.edge(e).minLen;
+});
+g.node(u).rank = util.max(minLens);
+});
+}
+},{"../util":26,"graphlib":28}],24:[function(require,module,exports){
+module.exports = {
+slack: slack
+};
+/*
+* A helper to calculate the slack between two nodes (`u` and `v`) given a
+* `minLen` constraint. The slack represents how much the distance between `u`
+* and `v` could shrink while maintaining the `minLen` constraint. If the value
+* is negative then the constraint is currently violated.
+*
+This function requires that `u` and `v` are in `graph` and they both have a
+`rank` attribute.
+*/
+function slack(graph, u, v, minLen) {
+return Math.abs(graph.node(u).rank - graph.node(v).rank) - minLen;
+}
+},{}],25:[function(require,module,exports){
+var util = require('../util'),
+rankUtil = require('./rankUtil');
+module.exports = simplex;
+function simplex(graph, spanningTree) {
+// The network simplex algorithm repeatedly replaces edges of
+// the spanning tree with negative cut values until no such
+// edge exists.
+initCutValues(graph, spanningTree);
+while (true) {
+var e = leaveEdge(spanningTree);
+if (e === null) break;
+var f = enterEdge(graph, spanningTree, e);
+exchange(graph, spanningTree, e, f);
+}
+}
+/*
+* Set the cut values of edges in the spanning tree by a depth-first
+* postorder traversal.  The cut value corresponds to the cost, in
+* terms of a ranking's edge length sum, of lengthening an edge.
+* Negative cut values typically indicate edges that would yield a
+* smaller edge length sum if they were lengthened.
+*/
+function initCutValues(graph, spanningTree) {
+computeLowLim(spanningTree);
+spanningTree.eachEdge(function(id, u, v, treeValue) {
+treeValue.cutValue = 0;
+});
+// Propagate cut values up the tree.
+function dfs(n) {
+var children = spanningTree.successors(n);
+for (var c in children) {
+var child = children[c];
+dfs(child);
+}
+if (n !== spanningTree.graph().root) {
+setCutValue(graph, spanningTree, n);
+}
+}
+dfs(spanningTree.graph().root);
+}
+/*
+* Perform a DFS postorder traversal, labeling each node v with
+* its traversal order 'lim(v)' and the minimum traversal number
+* of any of its descendants 'low(v)'.  This provides an efficient
+* way to test whether u is an ancestor of v since
+* low(u) <= lim(v) <= lim(u) if and only if u is an ancestor.
+*/
+function computeLowLim(tree) {
+var postOrderNum = 0;
+function dfs(n) {
+var children = tree.successors(n);
+var low = postOrderNum;
+for (var c in children) {
+var child = children[c];
+dfs(child);
+low = Math.min(low, tree.node(child).low);
+}
+tree.node(n).low = low;
+tree.node(n).lim = postOrderNum++;
+}
+dfs(tree.graph().root);
+}
+/*
+* To compute the cut value of the edge parent -> child, we consider
+* it and any other graph edges to or from the child.
+*          parent
+*             |
+*           child
+*          /      \
+*         u        v
+*/
+function setCutValue(graph, tree, child) {
+var parentEdge = tree.inEdges(child)[0];
+// List of child's children in the spanning tree.
+var grandchildren = [];
+var grandchildEdges = tree.outEdges(child);
+for (var gce in grandchildEdges) {
+grandchildren.push(tree.target(grandchildEdges[gce]));
+}
+var cutValue = 0;
+// TODO: Replace unit increment/decrement with edge weights.
+var E = 0;    // Edges from child to grandchild's subtree.
+var F = 0;    // Edges to child from grandchild's subtree.
+var G = 0;    // Edges from child to nodes outside of child's subtree.
+var H = 0;    // Edges from nodes outside of child's subtree to child.
+// Consider all graph edges from child.
+var outEdges = graph.outEdges(child);
+var gc;
+for (var oe in outEdges) {
+var succ = graph.target(outEdges[oe]);
+for (gc in grandchildren) {
+if (inSubtree(tree, succ, grandchildren[gc])) {
+E++;
+}
+}
+if (!inSubtree(tree, succ, child)) {
+G++;
+}
+}
+// Consider all graph edges to child.
+var inEdges = graph.inEdges(child);
+for (var ie in inEdges) {
+var pred = graph.source(inEdges[ie]);
+for (gc in grandchildren) {
+if (inSubtree(tree, pred, grandchildren[gc])) {
+F++;
+}
+}
+if (!inSubtree(tree, pred, child)) {
+H++;
+}
+}
+// Contributions depend on the alignment of the parent -> child edge
+// and the child -> u or v edges.
+var grandchildCutSum = 0;
+for (gc in grandchildren) {
+var cv = tree.edge(grandchildEdges[gc]).cutValue;
+if (!tree.edge(grandchildEdges[gc]).reversed) {
+grandchildCutSum += cv;
+} else {
+grandchildCutSum -= cv;
+}
+}
+if (!tree.edge(parentEdge).reversed) {
+cutValue += grandchildCutSum - E + F - G + H;
+} else {
+cutValue -= grandchildCutSum - E + F - G + H;
+}
+tree.edge(parentEdge).cutValue = cutValue;
+}
+/*
+* Return whether n is a node in the subtree with the given
+* root.
+*/
+function inSubtree(tree, n, root) {
+return (tree.node(root).low <= tree.node(n).lim &&
+tree.node(n).lim <= tree.node(root).lim);
+}
+/*
+* Return an edge from the tree with a negative cut value, or null if there
+* is none.
+*/
+function leaveEdge(tree) {
+var edges = tree.edges();
+for (var n in edges) {
+var e = edges[n];
+var treeValue = tree.edge(e);
+if (treeValue.cutValue < 0) {
+return e;
+}
+}
+return null;
+}
+/*
+* The edge e should be an edge in the tree, with an underlying edge
+* in the graph, with a negative cut value.  Of the two nodes incident
+* on the edge, take the lower one.  enterEdge returns an edge with
+* minimum slack going from outside of that node's subtree to inside
+* of that node's subtree.
+*/
+function enterEdge(graph, tree, e) {
+var source = tree.source(e);
+var target = tree.target(e);
+var lower = tree.node(target).lim < tree.node(source).lim ? target : source;
+// Is the tree edge aligned with the graph edge?
+var aligned = !tree.edge(e).reversed;
+var minSlack = Number.POSITIVE_INFINITY;
+var minSlackEdge;
+if (aligned) {
+graph.eachEdge(function(id, u, v, value) {
+if (id !== e && inSubtree(tree, u, lower) && !inSubtree(tree, v, lower)) {
+var slack = rankUtil.slack(graph, u, v, value.minLen);
+if (slack < minSlack) {
+minSlack = slack;
+minSlackEdge = id;
+}
+}
+});
+} else {
+graph.eachEdge(function(id, u, v, value) {
+if (id !== e && !inSubtree(tree, u, lower) && inSubtree(tree, v, lower)) {
+var slack = rankUtil.slack(graph, u, v, value.minLen);
+if (slack < minSlack) {
+minSlack = slack;
+minSlackEdge = id;
+}
+}
+});
+}
+if (minSlackEdge === undefined) {
+var outside = [];
+var inside = [];
+graph.eachNode(function(id) {
+if (!inSubtree(tree, id, lower)) {
+outside.push(id);
+} else {
+inside.push(id);
+}
+});
+throw new Error('No edge found from outside of tree to inside');
+}
+return minSlackEdge;
+}
+/*
+* Replace edge e with edge f in the tree, recalculating the tree root,
+* the nodes' low and lim properties and the edges' cut values.
+*/
+function exchange(graph, tree, e, f) {
+tree.delEdge(e);
+var source = graph.source(f);
+var target = graph.target(f);
+// Redirect edges so that target is the root of its subtree.
+function redirect(v) {
+var edges = tree.inEdges(v);
+for (var i in edges) {
+var e = edges[i];
+var u = tree.source(e);
+var value = tree.edge(e);
+redirect(u);
+tree.delEdge(e);
+value.reversed = !value.reversed;
+tree.addEdge(e, v, u, value);
+}
+}
+redirect(target);
+var root = source;
+var edges = tree.inEdges(root);
+while (edges.length > 0) {
+root = tree.source(edges[0]);
+edges = tree.inEdges(root);
+}
+tree.graph().root = root;
+tree.addEdge(null, source, target, {cutValue: 0});
+initCutValues(graph, tree);
+adjustRanks(graph, tree);
+}
+/*
+* Reset the ranks of all nodes based on the current spanning tree.
+* The rank of the tree's root remains unchanged, while all other
+* nodes are set to the sum of minimum length constraints along
+* the path from the root.
+*/
+function adjustRanks(graph, tree) {
+function dfs(p) {
+var children = tree.successors(p);
+children.forEach(function(c) {
+var minLen = minimumLength(graph, p, c);
+graph.node(c).rank = graph.node(p).rank + minLen;
+dfs(c);
+});
+}
+dfs(tree.graph().root);
+}
+/*
+* If u and v are connected by some edges in the graph, return the
+* minimum length of those edges, as a positive number if v succeeds
+* u and as a negative number if v precedes u.
+*/
+function minimumLength(graph, u, v) {
+var outEdges = graph.outEdges(u, v);
+if (outEdges.length > 0) {
+return util.max(outEdges.map(function(e) {
+return graph.edge(e).minLen;
+}));
+}
+var inEdges = graph.inEdges(u, v);
+if (inEdges.length > 0) {
+return -util.max(inEdges.map(function(e) {
+return graph.edge(e).minLen;
+}));
+}
+}
+},{"../util":26,"./rankUtil":24}],26:[function(require,module,exports){
+/*
+* Returns the smallest value in the array.
+*/
+exports.min = function(values) {
+return Math.min.apply(Math, values);
+};
+/*
+* Returns the largest value in the array.
+*/
+exports.max = function(values) {
+return Math.max.apply(Math, values);
+};
+/*
+* Returns `true` only if `f(x)` is `true` for all `x` in `xs`. Otherwise
+* returns `false`. This function will return immediately if it finds a
+* case where `f(x)` does not hold.
+*/
+exports.all = function(xs, f) {
+for (var i = 0; i < xs.length; ++i) {
+if (!f(xs[i])) {
+return false;
+}
+}
+return true;
+};
+/*
+* Accumulates the sum of elements in the given array using the `+` operator.
+*/
+exports.sum = function(values) {
+return values.reduce(function(acc, x) { return acc + x; }, 0);
+};
+/*
+* Returns an array of all values in the given object.
+*/
+exports.values = function(obj) {
+return Object.keys(obj).map(function(k) { return obj[k]; });
+};
+exports.shuffle = function(array) {
+for (i = array.length - 1; i > 0; --i) {
+var j = Math.floor(Math.random() * (i + 1));
+var aj = array[j];
+array[j] = array[i];
+array[i] = aj;
+}
+};
+exports.propertyAccessor = function(self, config, field, setHook) {
+return function(x) {
+if (!arguments.length) return config[field];
+config[field] = x;
+if (setHook) setHook(x);
+return self;
+};
+};
+/*
+* Given a layered, directed graph with `rank` and `order` node attributes,
+* this function returns an array of ordered ranks. Each rank contains an array
+* of the ids of the nodes in that rank in the order specified by the `order`
+* attribute.
+*/
+exports.ordering = function(g) {
+var ordering = [];
+g.eachNode(function(u, value) {
+var rank = ordering[value.rank] || (ordering[value.rank] = []);
+rank[value.order] = u;
+});
+return ordering;
+};
+/*
+* A filter that can be used with `filterNodes` to get a graph that only
+* includes nodes that do not contain others nodes.
+*/
+exports.filterNonSubgraphs = function(g) {
+return function(u) {
+return g.children(u).length === 0;
+};
+};
+/*
+* Returns a new function that wraps `func` with a timer. The wrapper logs the
+* time it takes to execute the function.
+*
+* The timer will be enabled provided `log.level >= 1`.
+*/
+function time(name, func) {
+return function() {
+var start = new Date().getTime();
+try {
+return func.apply(null, arguments);
+} finally {
+log(1, name + ' time: ' + (new Date().getTime() - start) + 'ms');
+}
+};
+}
+time.enabled = false;
+exports.time = time;
+/*
+* A global logger with the specification `log(level, message, ...)` that
+* will log a message to the console if `log.level >= level`.
+*/
+function log(level) {
+if (log.level >= level) {
+console.log.apply(console, Array.prototype.slice.call(arguments, 1));
+}
+}
+log.level = 0;
+exports.log = log;
+},{}],27:[function(require,module,exports){
+module.exports = '0.4.5';
+},{}],28:[function(require,module,exports){
+exports.Graph = require("./lib/Graph");
+exports.Digraph = require("./lib/Digraph");
+exports.CGraph = require("./lib/CGraph");
+exports.CDigraph = require("./lib/CDigraph");
+require("./lib/graph-converters");
+exports.alg = {
+isAcyclic: require("./lib/alg/isAcyclic"),
+components: require("./lib/alg/components"),
+dijkstra: require("./lib/alg/dijkstra"),
+dijkstraAll: require("./lib/alg/dijkstraAll"),
+findCycles: require("./lib/alg/findCycles"),
+floydWarshall: require("./lib/alg/floydWarshall"),
+postorder: require("./lib/alg/postorder"),
+preorder: require("./lib/alg/preorder"),
+prim: require("./lib/alg/prim"),
+tarjan: require("./lib/alg/tarjan"),
+topsort: require("./lib/alg/topsort")
+};
+exports.converter = {
+json: require("./lib/converter/json.js")
+};
+var filter = require("./lib/filter");
+exports.filter = {
+all: filter.all,
+nodesFromList: filter.nodesFromList
+};
+exports.version = require("./lib/version");
+},{"./lib/CDigraph":30,"./lib/CGraph":31,"./lib/Digraph":32,"./lib/Graph":33,"./lib/alg/components":34,"./lib/alg/dijkstra":35,"./lib/alg/dijkstraAll":36,"./lib/alg/findCycles":37,"./lib/alg/floydWarshall":38,"./lib/alg/isAcyclic":39,"./lib/alg/postorder":40,"./lib/alg/preorder":41,"./lib/alg/prim":42,"./lib/alg/tarjan":43,"./lib/alg/topsort":44,"./lib/converter/json.js":46,"./lib/filter":47,"./lib/graph-converters":48,"./lib/version":50}],29:[function(require,module,exports){
+/* jshint -W079 */
+var Set = require("cp-data").Set;
+/* jshint +W079 */
+module.exports = BaseGraph;
+function BaseGraph() {
+// The value assigned to the graph itself.
+this._value = undefined;
+// Map of node id -> { id, value }
+this._nodes = {};
+// Map of edge id -> { id, u, v, value }
+this._edges = {};
+// Used to generate a unique id in the graph
+this._nextId = 0;
+}
+// Number of nodes
+BaseGraph.prototype.order = function() {
+return Object.keys(this._nodes).length;
+};
+// Number of edges
+BaseGraph.prototype.size = function() {
+return Object.keys(this._edges).length;
+};
+// Accessor for graph level value
+BaseGraph.prototype.graph = function(value) {
+if (arguments.length === 0) {
+return this._value;
+}
+this._value = value;
+};
+BaseGraph.prototype.hasNode = function(u) {
+return u in this._nodes;
+};
+BaseGraph.prototype.node = function(u, value) {
+var node = this._strictGetNode(u);
+if (arguments.length === 1) {
+return node.value;
+}
+node.value = value;
+};
+BaseGraph.prototype.nodes = function() {
+var nodes = [];
+this.eachNode(function(id) { nodes.push(id); });
+return nodes;
+};
+BaseGraph.prototype.eachNode = function(func) {
+for (var k in this._nodes) {
+var node = this._nodes[k];
+func(node.id, node.value);
+}
+};
+BaseGraph.prototype.hasEdge = function(e) {
+return e in this._edges;
+};
+BaseGraph.prototype.edge = function(e, value) {
+var edge = this._strictGetEdge(e);
+if (arguments.length === 1) {
+return edge.value;
+}
+edge.value = value;
+};
+BaseGraph.prototype.edges = function() {
+var es = [];
+this.eachEdge(function(id) { es.push(id); });
+return es;
+};
+BaseGraph.prototype.eachEdge = function(func) {
+for (var k in this._edges) {
+var edge = this._edges[k];
+func(edge.id, edge.u, edge.v, edge.value);
+}
+};
+BaseGraph.prototype.incidentNodes = function(e) {
+var edge = this._strictGetEdge(e);
+return [edge.u, edge.v];
+};
+BaseGraph.prototype.addNode = function(u, value) {
+if (u === undefined || u === null) {
+do {
+u = "_" + (++this._nextId);
+} while (this.hasNode(u));
+} else if (this.hasNode(u)) {
+throw new Error("Graph already has node '" + u + "'");
+}
+this._nodes[u] = { id: u, value: value };
+return u;
+};
+BaseGraph.prototype.delNode = function(u) {
+this._strictGetNode(u);
+this.incidentEdges(u).forEach(function(e) { this.delEdge(e); }, this);
+delete this._nodes[u];
+};
+// inMap and outMap are opposite sides of an incidence map. For example, for
+// Graph these would both come from the _incidentEdges map, while for Digraph
+// they would come from _inEdges and _outEdges.
+BaseGraph.prototype._addEdge = function(e, u, v, value, inMap, outMap) {
+this._strictGetNode(u);
+this._strictGetNode(v);
+if (e === undefined || e === null) {
+do {
+e = "_" + (++this._nextId);
+} while (this.hasEdge(e));
+}
+else if (this.hasEdge(e)) {
+throw new Error("Graph already has edge '" + e + "'");
+}
+this._edges[e] = { id: e, u: u, v: v, value: value };
+addEdgeToMap(inMap[v], u, e);
+addEdgeToMap(outMap[u], v, e);
+return e;
+};
+// See note for _addEdge regarding inMap and outMap.
+BaseGraph.prototype._delEdge = function(e, inMap, outMap) {
+var edge = this._strictGetEdge(e);
+delEdgeFromMap(inMap[edge.v], edge.u, e);
+delEdgeFromMap(outMap[edge.u], edge.v, e);
+delete this._edges[e];
+};
+BaseGraph.prototype.copy = function() {
+var copy = new this.constructor();
+copy.graph(this.graph());
+this.eachNode(function(u, value) { copy.addNode(u, value); });
+this.eachEdge(function(e, u, v, value) { copy.addEdge(e, u, v, value); });
+copy._nextId = this._nextId;
+return copy;
+};
+BaseGraph.prototype.filterNodes = function(filter) {
+var copy = new this.constructor();
+copy.graph(this.graph());
+this.eachNode(function(u, value) {
+if (filter(u)) {
+copy.addNode(u, value);
+}
+});
+this.eachEdge(function(e, u, v, value) {
+if (copy.hasNode(u) && copy.hasNode(v)) {
+copy.addEdge(e, u, v, value);
+}
+});
+return copy;
+};
+BaseGraph.prototype._strictGetNode = function(u) {
+var node = this._nodes[u];
+if (node === undefined) {
+throw new Error("Node '" + u + "' is not in graph");
+}
+return node;
+};
+BaseGraph.prototype._strictGetEdge = function(e) {
+var edge = this._edges[e];
+if (edge === undefined) {
+throw new Error("Edge '" + e + "' is not in graph");
+}
+return edge;
+};
+function addEdgeToMap(map, v, e) {
+(map[v] || (map[v] = new Set())).add(e);
+}
+function delEdgeFromMap(map, v, e) {
+var vEntry = map[v];
+vEntry.remove(e);
+if (vEntry.size() === 0) {
+delete map[v];
+}
+}
+},{"cp-data":5}],30:[function(require,module,exports){
+var Digraph = require("./Digraph"),
+compoundify = require("./compoundify");
+var CDigraph = compoundify(Digraph);
+module.exports = CDigraph;
+CDigraph.fromDigraph = function(src) {
+var g = new CDigraph(),
+graphValue = src.graph();
+if (graphValue !== undefined) {
+g.graph(graphValue);
+}
+src.eachNode(function(u, value) {
+if (value === undefined) {
+g.addNode(u);
+} else {
+g.addNode(u, value);
+}
+});
+src.eachEdge(function(e, u, v, value) {
+if (value === undefined) {
+g.addEdge(null, u, v);
+} else {
+g.addEdge(null, u, v, value);
+}
+});
+return g;
+};
+CDigraph.prototype.toString = function() {
+return "CDigraph " + JSON.stringify(this, null, 2);
+};
+},{"./Digraph":32,"./compoundify":45}],31:[function(require,module,exports){
+var Graph = require("./Graph"),
+compoundify = require("./compoundify");
+var CGraph = compoundify(Graph);
+module.exports = CGraph;
+CGraph.fromGraph = function(src) {
+var g = new CGraph(),
+graphValue = src.graph();
+if (graphValue !== undefined) {
+g.graph(graphValue);
+}
+src.eachNode(function(u, value) {
+if (value === undefined) {
+g.addNode(u);
+} else {
+g.addNode(u, value);
+}
+});
+src.eachEdge(function(e, u, v, value) {
+if (value === undefined) {
+g.addEdge(null, u, v);
+} else {
+g.addEdge(null, u, v, value);
+}
+});
+return g;
+};
+CGraph.prototype.toString = function() {
+return "CGraph " + JSON.stringify(this, null, 2);
+};
+},{"./Graph":33,"./compoundify":45}],32:[function(require,module,exports){
+/*
+* This file is organized with in the following order:
+*
+* Exports
+* Graph constructors
+* Graph queries (e.g. nodes(), edges()
+* Graph mutators
+* Helper functions
+*/
+var util = require("./util"),
+BaseGraph = require("./BaseGraph"),
+/* jshint -W079 */
+Set = require("cp-data").Set;
+/* jshint +W079 */
+module.exports = Digraph;
+/*
+* Constructor to create a new directed multi-graph.
+*/
+function Digraph() {
+BaseGraph.call(this);
+/*! Map of sourceId -> {targetId -> Set of edge ids} */
+this._inEdges = {};
+/*! Map of targetId -> {sourceId -> Set of edge ids} */
+this._outEdges = {};
+}
+Digraph.prototype = new BaseGraph();
+Digraph.prototype.constructor = Digraph;
+/*
+* Always returns `true`.
+*/
+Digraph.prototype.isDirected = function() {
+return true;
+};
+/*
+* Returns all successors of the node with the id `u`. That is, all nodes
+* that have the node `u` as their source are returned.
+*
+* If no node `u` exists in the graph this function throws an Error.
+*
+* @param {String} u a node id
+*/
+Digraph.prototype.successors = function(u) {
+this._strictGetNode(u);
+return Object.keys(this._outEdges[u])
+.map(function(v) { return this._nodes[v].id; }, this);
+};
+/*
+* Returns all predecessors of the node with the id `u`. That is, all nodes
+* that have the node `u` as their target are returned.
+*
+* If no node `u` exists in the graph this function throws an Error.
+*
+* @param {String} u a node id
+*/
+Digraph.prototype.predecessors = function(u) {
+this._strictGetNode(u);
+return Object.keys(this._inEdges[u])
+.map(function(v) { return this._nodes[v].id; }, this);
+};
+/*
+* Returns all nodes that are adjacent to the node with the id `u`. In other
+* words, this function returns the set of all successors and predecessors of
+* node `u`.
+*
+* @param {String} u a node id
+*/
+Digraph.prototype.neighbors = function(u) {
+return Set.union([this.successors(u), this.predecessors(u)]).keys();
+};
+/*
+* Returns all nodes in the graph that have no in-edges.
+*/
+Digraph.prototype.sources = function() {
+var self = this;
+return this._filterNodes(function(u) {
+// This could have better space characteristics if we had an inDegree function.
+return self.inEdges(u).length === 0;
+});
+};
+/*
+* Returns all nodes in the graph that have no out-edges.
+*/
+Digraph.prototype.sinks = function() {
+var self = this;
+return this._filterNodes(function(u) {
+// This could have better space characteristics if we have an outDegree function.
+return self.outEdges(u).length === 0;
+});
+};
+/*
+* Returns the source node incident on the edge identified by the id `e`. If no
+* such edge exists in the graph this function throws an Error.
+*
+* @param {String} e an edge id
+*/
+Digraph.prototype.source = function(e) {
+return this._strictGetEdge(e).u;
+};
+/*
+* Returns the target node incident on the edge identified by the id `e`. If no
+* such edge exists in the graph this function throws an Error.
+*
+* @param {String} e an edge id
+*/
+Digraph.prototype.target = function(e) {
+return this._strictGetEdge(e).v;
+};
+/*
+* Returns an array of ids for all edges in the graph that have the node
+* `target` as their target. If the node `target` is not in the graph this
+* function raises an Error.
+*
+* Optionally a `source` node can also be specified. This causes the results
+* to be filtered such that only edges from `source` to `target` are included.
+* If the node `source` is specified but is not in the graph then this function
+* raises an Error.
+*
+* @param {String} target the target node id
+* @param {String} [source] an optional source node id
+*/
+Digraph.prototype.inEdges = function(target, source) {
+this._strictGetNode(target);
+var results = Set.union(util.values(this._inEdges[target])).keys();
+if (arguments.length > 1) {
+this._strictGetNode(source);
+results = results.filter(function(e) { return this.source(e) === source; }, this);
+}
+return results;
+};
+/*
+* Returns an array of ids for all edges in the graph that have the node
+* `source` as their source. If the node `source` is not in the graph this
+* function raises an Error.
+*
+* Optionally a `target` node may also be specified. This causes the results
+* to be filtered such that only edges from `source` to `target` are included.
+* If the node `target` is specified but is not in the graph then this function
+* raises an Error.
+*
+* @param {String} source the source node id
+* @param {String} [target] an optional target node id
+*/
+Digraph.prototype.outEdges = function(source, target) {
+this._strictGetNode(source);
+var results = Set.union(util.values(this._outEdges[source])).keys();
+if (arguments.length > 1) {
+this._strictGetNode(target);
+results = results.filter(function(e) { return this.target(e) === target; }, this);
+}
+return results;
+};
+/*
+* Returns an array of ids for all edges in the graph that have the `u` as
+* their source or their target. If the node `u` is not in the graph this
+* function raises an Error.
+*
+* Optionally a `v` node may also be specified. This causes the results to be
+* filtered such that only edges between `u` and `v` - in either direction -
+* are included. IF the node `v` is specified but not in the graph then this
+* function raises an Error.
+*
+* @param {String} u the node for which to find incident edges
+* @param {String} [v] option node that must be adjacent to `u`
+*/
+Digraph.prototype.incidentEdges = function(u, v) {
+if (arguments.length > 1) {
+return Set.union([this.outEdges(u, v), this.outEdges(v, u)]).keys();
+} else {
+return Set.union([this.inEdges(u), this.outEdges(u)]).keys();
+}
+};
+/*
+* Returns a string representation of this graph.
+*/
+Digraph.prototype.toString = function() {
+return "Digraph " + JSON.stringify(this, null, 2);
+};
+/*
+* Adds a new node with the id `u` to the graph and assigns it the value
+* `value`. If a node with the id is already a part of the graph this function
+* throws an Error.
+*
+* @param {String} u a node id
+* @param {Object} [value] an optional value to attach to the node
+*/
+Digraph.prototype.addNode = function(u, value) {
+u = BaseGraph.prototype.addNode.call(this, u, value);
+this._inEdges[u] = {};
+this._outEdges[u] = {};
+return u;
+};
+/*
+* Removes a node from the graph that has the id `u`. Any edges incident on the
+* node are also removed. If the graph does not contain a node with the id this
+* function will throw an Error.
+*
+* @param {String} u a node id
+*/
+Digraph.prototype.delNode = function(u) {
+BaseGraph.prototype.delNode.call(this, u);
+delete this._inEdges[u];
+delete this._outEdges[u];
+};
+/*
+* Adds a new edge to the graph with the id `e` from a node with the id `source`
+* to a node with an id `target` and assigns it the value `value`. This graph
+* allows more than one edge from `source` to `target` as long as the id `e`
+* is unique in the set of edges. If `e` is `null` the graph will assign a
+* unique identifier to the edge.
+*
+* If `source` or `target` are not present in the graph this function will
+* throw an Error.
+*
+* @param {String} [e] an edge id
+* @param {String} source the source node id
+* @param {String} target the target node id
+* @param {Object} [value] an optional value to attach to the edge
+*/
+Digraph.prototype.addEdge = function(e, source, target, value) {
+return BaseGraph.prototype._addEdge.call(this, e, source, target, value,
+this._inEdges, this._outEdges);
+};
+/*
+* Removes an edge in the graph with the id `e`. If no edge in the graph has
+* the id `e` this function will throw an Error.
+*
+* @param {String} e an edge id
+*/
+Digraph.prototype.delEdge = function(e) {
+BaseGraph.prototype._delEdge.call(this, e, this._inEdges, this._outEdges);
+};
+// Unlike BaseGraph.filterNodes, this helper just returns nodes that
+// satisfy a predicate.
+Digraph.prototype._filterNodes = function(pred) {
+var filtered = [];
+this.eachNode(function(u) {
+if (pred(u)) {
+filtered.push(u);
+}
+});
+return filtered;
+};
+},{"./BaseGraph":29,"./util":49,"cp-data":5}],33:[function(require,module,exports){
+/*
+* This file is organized with in the following order:
+*
+* Exports
+* Graph constructors
+* Graph queries (e.g. nodes(), edges()
+* Graph mutators
+* Helper functions
+*/
+var util = require("./util"),
+BaseGraph = require("./BaseGraph"),
+/* jshint -W079 */
+Set = require("cp-data").Set;
+/* jshint +W079 */
+module.exports = Graph;
+/*
+* Constructor to create a new undirected multi-graph.
+*/
+function Graph() {
+BaseGraph.call(this);
+/*! Map of nodeId -> { otherNodeId -> Set of edge ids } */
+this._incidentEdges = {};
+}
+Graph.prototype = new BaseGraph();
+Graph.prototype.constructor = Graph;
+/*
+* Always returns `false`.
+*/
+Graph.prototype.isDirected = function() {
+return false;
+};
+/*
+* Returns all nodes that are adjacent to the node with the id `u`.
+*
+* @param {String} u a node id
+*/
+Graph.prototype.neighbors = function(u) {
+this._strictGetNode(u);
+return Object.keys(this._incidentEdges[u])
+.map(function(v) { return this._nodes[v].id; }, this);
+};
+/*
+* Returns an array of ids for all edges in the graph that are incident on `u`.
+* If the node `u` is not in the graph this function raises an Error.
+*
+* Optionally a `v` node may also be specified. This causes the results to be
+* filtered such that only edges between `u` and `v` are included. If the node
+* `v` is specified but not in the graph then this function raises an Error.
+*
+* @param {String} u the node for which to find incident edges
+* @param {String} [v] option node that must be adjacent to `u`
+*/
+Graph.prototype.incidentEdges = function(u, v) {
+this._strictGetNode(u);
+if (arguments.length > 1) {
+this._strictGetNode(v);
+return v in this._incidentEdges[u] ? this._incidentEdges[u][v].keys() : [];
+} else {
+return Set.union(util.values(this._incidentEdges[u])).keys();
+}
+};
+/*
+* Returns a string representation of this graph.
+*/
+Graph.prototype.toString = function() {
+return "Graph " + JSON.stringify(this, null, 2);
+};
+/*
+* Adds a new node with the id `u` to the graph and assigns it the value
+* `value`. If a node with the id is already a part of the graph this function
+* throws an Error.
+*
+* @param {String} u a node id
+* @param {Object} [value] an optional value to attach to the node
+*/
+Graph.prototype.addNode = function(u, value) {
+u = BaseGraph.prototype.addNode.call(this, u, value);
+this._incidentEdges[u] = {};
+return u;
+};
+/*
+* Removes a node from the graph that has the id `u`. Any edges incident on the
+* node are also removed. If the graph does not contain a node with the id this
+* function will throw an Error.
+*
+* @param {String} u a node id
+*/
+Graph.prototype.delNode = function(u) {
+BaseGraph.prototype.delNode.call(this, u);
+delete this._incidentEdges[u];
+};
+/*
+* Adds a new edge to the graph with the id `e` between a node with the id `u`
+* and a node with an id `v` and assigns it the value `value`. This graph
+* allows more than one edge between `u` and `v` as long as the id `e`
+* is unique in the set of edges. If `e` is `null` the graph will assign a
+* unique identifier to the edge.
+*
+* If `u` or `v` are not present in the graph this function will throw an
+* Error.
+*
+* @param {String} [e] an edge id
+* @param {String} u the node id of one of the adjacent nodes
+* @param {String} v the node id of the other adjacent node
+* @param {Object} [value] an optional value to attach to the edge
+*/
+Graph.prototype.addEdge = function(e, u, v, value) {
+return BaseGraph.prototype._addEdge.call(this, e, u, v, value,
+this._incidentEdges, this._incidentEdges);
+};
+/*
+* Removes an edge in the graph with the id `e`. If no edge in the graph has
+* the id `e` this function will throw an Error.
+*
+* @param {String} e an edge id
+*/
+Graph.prototype.delEdge = function(e) {
+BaseGraph.prototype._delEdge.call(this, e, this._incidentEdges, this._incidentEdges);
+};
+},{"./BaseGraph":29,"./util":49,"cp-data":5}],34:[function(require,module,exports){
+/* jshint -W079 */
+var Set = require("cp-data").Set;
+/* jshint +W079 */
+module.exports = components;
+/**
+* Finds all [connected components][] in a graph and returns an array of these
+* components. Each component is itself an array that contains the ids of nodes
+* in the component.
+*
+* This function only works with undirected Graphs.
+*
+* [connected components]: http://en.wikipedia.org/wiki/Connected_component_(graph_theory)
+*
+* @param {Graph} g the graph to search for components
+*/
+function components(g) {
+var results = [];
+var visited = new Set();
+function dfs(v, component) {
+if (!visited.has(v)) {
+visited.add(v);
+component.push(v);
+g.neighbors(v).forEach(function(w) {
+dfs(w, component);
+});
+}
+}
+g.nodes().forEach(function(v) {
+var component = [];
+dfs(v, component);
+if (component.length > 0) {
+results.push(component);
+}
+});
+return results;
+}
+},{"cp-data":5}],35:[function(require,module,exports){
+var PriorityQueue = require("cp-data").PriorityQueue;
+module.exports = dijkstra;
+/**
+* This function is an implementation of [Dijkstra's algorithm][] which finds
+* the shortest path from **source** to all other nodes in **g**. This
+* function returns a map of `u -> { distance, predecessor }`. The distance
+* property holds the sum of the weights from **source** to `u` along the
+* shortest path or `Number.POSITIVE_INFINITY` if there is no path from
+* **source**. The predecessor property can be used to walk the individual
+* elements of the path from **source** to **u** in reverse order.
+*
+* This function takes an optional `weightFunc(e)` which returns the
+* weight of the edge `e`. If no weightFunc is supplied then each edge is
+* assumed to have a weight of 1. This function throws an Error if any of
+* the traversed edges have a negative edge weight.
+*
+* This function takes an optional `incidentFunc(u)` which returns the ids of
+* all edges incident to the node `u` for the purposes of shortest path
+* traversal. By default this function uses the `g.outEdges` for Digraphs and
+* `g.incidentEdges` for Graphs.
+*
+* This function takes `O((|E| + |V|) * log |V|)` time.
+*
+* [Dijkstra's algorithm]: http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm
+*
+* @param {Graph} g the graph to search for shortest paths from **source**
+* @param {Object} source the source from which to start the search
+* @param {Function} [weightFunc] optional weight function
+* @param {Function} [incidentFunc] optional incident function
+*/
+function dijkstra(g, source, weightFunc, incidentFunc) {
+var results = {},
+pq = new PriorityQueue();
+function updateNeighbors(e) {
+var incidentNodes = g.incidentNodes(e),
+v = incidentNodes[0] !== u ? incidentNodes[0] : incidentNodes[1],
+vEntry = results[v],
+weight = weightFunc(e),
+distance = uEntry.distance + weight;
+if (weight < 0) {
+throw new Error("dijkstra does not allow negative edge weights. Bad edge: " + e + " Weight: " + weight);
+}
+if (distance < vEntry.distance) {
+vEntry.distance = distance;
+vEntry.predecessor = u;
+pq.decrease(v, distance);
+}
+}
+weightFunc = weightFunc || function() { return 1; };
+incidentFunc = incidentFunc || (g.isDirected()
+? function(u) { return g.outEdges(u); }
+: function(u) { return g.incidentEdges(u); });
+g.eachNode(function(u) {
+var distance = u === source ? 0 : Number.POSITIVE_INFINITY;
+results[u] = { distance: distance };
+pq.add(u, distance);
+});
+var u, uEntry;
+while (pq.size() > 0) {
+u = pq.removeMin();
+uEntry = results[u];
+if (uEntry.distance === Number.POSITIVE_INFINITY) {
+break;
+}
+incidentFunc(u).forEach(updateNeighbors);
+}
+return results;
+}
+},{"cp-data":5}],36:[function(require,module,exports){
+var dijkstra = require("./dijkstra");
+module.exports = dijkstraAll;
+/**
+* This function finds the shortest path from each node to every other
+* reachable node in the graph. It is similar to [alg.dijkstra][], but
+* instead of returning a single-source array, it returns a mapping of
+* of `source -> alg.dijksta(g, source, weightFunc, incidentFunc)`.
+*
+* This function takes an optional `weightFunc(e)` which returns the
+* weight of the edge `e`. If no weightFunc is supplied then each edge is
+* assumed to have a weight of 1. This function throws an Error if any of
+* the traversed edges have a negative edge weight.
+*
+* This function takes an optional `incidentFunc(u)` which returns the ids of
+* all edges incident to the node `u` for the purposes of shortest path
+* traversal. By default this function uses the `outEdges` function on the
+* supplied graph.
+*
+* This function takes `O(|V| * (|E| + |V|) * log |V|)` time.
+*
+* [alg.dijkstra]: dijkstra.js.html#dijkstra
+*
+* @param {Graph} g the graph to search for shortest paths from **source**
+* @param {Function} [weightFunc] optional weight function
+* @param {Function} [incidentFunc] optional incident function
+*/
+function dijkstraAll(g, weightFunc, incidentFunc) {
+var results = {};
+g.eachNode(function(u) {
+results[u] = dijkstra(g, u, weightFunc, incidentFunc);
+});
+return results;
+}
+},{"./dijkstra":35}],37:[function(require,module,exports){
+var tarjan = require("./tarjan");
+module.exports = findCycles;
+/*
+* Given a Digraph **g** this function returns all nodes that are part of a
+* cycle. Since there may be more than one cycle in a graph this function
+* returns an array of these cycles, where each cycle is itself represented
+* by an array of ids for each node involved in that cycle.
+*
+* [alg.isAcyclic][] is more efficient if you only need to determine whether
+* a graph has a cycle or not.
+*
+* [alg.isAcyclic]: isAcyclic.js.html#isAcyclic
+*
+* @param {Digraph} g the graph to search for cycles.
+*/
+function findCycles(g) {
+return tarjan(g).filter(function(cmpt) { return cmpt.length > 1; });
+}
+},{"./tarjan":43}],38:[function(require,module,exports){
+module.exports = floydWarshall;
+/**
+* This function is an implementation of the [Floyd-Warshall algorithm][],
+* which finds the shortest path from each node to every other reachable node
+* in the graph. It is similar to [alg.dijkstraAll][], but it handles negative
+* edge weights and is more efficient for some types of graphs. This function
+* returns a map of `source -> { target -> { distance, predecessor }`. The
+* distance property holds the sum of the weights from `source` to `target`
+* along the shortest path of `Number.POSITIVE_INFINITY` if there is no path
+* from `source`. The predecessor property can be used to walk the individual
+* elements of the path from `source` to `target` in reverse order.
+*
+* This function takes an optional `weightFunc(e)` which returns the
+* weight of the edge `e`. If no weightFunc is supplied then each edge is
+* assumed to have a weight of 1.
+*
+* This function takes an optional `incidentFunc(u)` which returns the ids of
+* all edges incident to the node `u` for the purposes of shortest path
+* traversal. By default this function uses the `outEdges` function on the
+* supplied graph.
+*
+* This algorithm takes O(|V|^3) time.
+*
+* [Floyd-Warshall algorithm]: https://en.wikipedia.org/wiki/Floyd-Warshall_algorithm
+* [alg.dijkstraAll]: dijkstraAll.js.html#dijkstraAll
+*
+* @param {Graph} g the graph to search for shortest paths from **source**
+* @param {Function} [weightFunc] optional weight function
+* @param {Function} [incidentFunc] optional incident function
+*/
+function floydWarshall(g, weightFunc, incidentFunc) {
+var results = {},
+nodes = g.nodes();
+weightFunc = weightFunc || function() { return 1; };
+incidentFunc = incidentFunc || (g.isDirected()
+? function(u) { return g.outEdges(u); }
+: function(u) { return g.incidentEdges(u); });
+nodes.forEach(function(u) {
+results[u] = {};
+results[u][u] = { distance: 0 };
+nodes.forEach(function(v) {
+if (u !== v) {
+results[u][v] = { distance: Number.POSITIVE_INFINITY };
+}
+});
+incidentFunc(u).forEach(function(e) {
+var incidentNodes = g.incidentNodes(e),
+v = incidentNodes[0] !== u ? incidentNodes[0] : incidentNodes[1],
+d = weightFunc(e);
+if (d < results[u][v].distance) {
+results[u][v] = { distance: d, predecessor: u };
+}
+});
+});
+nodes.forEach(function(k) {
+var rowK = results[k];
+nodes.forEach(function(i) {
+var rowI = results[i];
+nodes.forEach(function(j) {
+var ik = rowI[k];
+var kj = rowK[j];
+var ij = rowI[j];
+var altDistance = ik.distance + kj.distance;
+if (altDistance < ij.distance) {
+ij.distance = altDistance;
+ij.predecessor = kj.predecessor;
+}
+});
+});
+});
+return results;
+}
+},{}],39:[function(require,module,exports){
+var topsort = require("./topsort");
+module.exports = isAcyclic;
+/*
+* Given a Digraph **g** this function returns `true` if the graph has no
+* cycles and returns `false` if it does. This algorithm returns as soon as it
+* detects the first cycle.
+*
+* Use [alg.findCycles][] if you need the actual list of cycles in a graph.
+*
+* [alg.findCycles]: findCycles.js.html#findCycles
+*
+* @param {Digraph} g the graph to test for cycles
+*/
+function isAcyclic(g) {
+try {
+topsort(g);
+} catch (e) {
+if (e instanceof topsort.CycleException) return false;
+throw e;
+}
+return true;
+}
+},{"./topsort":44}],40:[function(require,module,exports){
+/* jshint -W079 */
+var Set = require("cp-data").Set;
+/* jshint +W079 */
+module.exports = postorder;
+// Postorder traversal of g, calling f for each visited node. Assumes the graph
+// is a tree.
+function postorder(g, root, f) {
+var visited = new Set();
+if (g.isDirected()) {
+throw new Error("This function only works for undirected graphs");
+}
+function dfs(u, prev) {
+if (visited.has(u)) {
+throw new Error("The input graph is not a tree: " + g);
+}
+visited.add(u);
+g.neighbors(u).forEach(function(v) {
+if (v !== prev) dfs(v, u);
+});
+f(u);
+}
+dfs(root);
+}
+},{"cp-data":5}],41:[function(require,module,exports){
+/* jshint -W079 */
+var Set = require("cp-data").Set;
+/* jshint +W079 */
+module.exports = preorder;
+// Preorder traversal of g, calling f for each visited node. Assumes the graph
+// is a tree.
+function preorder(g, root, f) {
+var visited = new Set();
+if (g.isDirected()) {
+throw new Error("This function only works for undirected graphs");
+}
+function dfs(u, prev) {
+if (visited.has(u)) {
+throw new Error("The input graph is not a tree: " + g);
+}
+visited.add(u);
+f(u);
+g.neighbors(u).forEach(function(v) {
+if (v !== prev) dfs(v, u);
+});
+}
+dfs(root);
+}
+},{"cp-data":5}],42:[function(require,module,exports){
+var Graph = require("../Graph"),
+PriorityQueue = require("cp-data").PriorityQueue;
+module.exports = prim;
+/**
+* [Prim's algorithm][] takes a connected undirected graph and generates a
+* [minimum spanning tree][]. This function returns the minimum spanning
+* tree as an undirected graph. This algorithm is derived from the description
+* in "Introduction to Algorithms", Third Edition, Cormen, et al., Pg 634.
+*
+* This function takes a `weightFunc(e)` which returns the weight of the edge
+* `e`. It throws an Error if the graph is not connected.
+*
+* This function takes `O(|E| log |V|)` time.
+*
+* [Prim's algorithm]: https://en.wikipedia.org/wiki/Prim's_algorithm
+* [minimum spanning tree]: https://en.wikipedia.org/wiki/Minimum_spanning_tree
+*
+* @param {Graph} g the graph used to generate the minimum spanning tree
+* @param {Function} weightFunc the weight function to use
+*/
+function prim(g, weightFunc) {
+var result = new Graph(),
+parents = {},
+pq = new PriorityQueue(),
+u;
+function updateNeighbors(e) {
+var incidentNodes = g.incidentNodes(e),
+v = incidentNodes[0] !== u ? incidentNodes[0] : incidentNodes[1],
+pri = pq.priority(v);
+if (pri !== undefined) {
+var edgeWeight = weightFunc(e);
+if (edgeWeight < pri) {
+parents[v] = u;
+pq.decrease(v, edgeWeight);
+}
+}
+}
+if (g.order() === 0) {
+return result;
+}
+g.eachNode(function(u) {
+pq.add(u, Number.POSITIVE_INFINITY);
+result.addNode(u);
+});
+// Start from an arbitrary node
+pq.decrease(g.nodes()[0], 0);
+var init = false;
+while (pq.size() > 0) {
+u = pq.removeMin();
+if (u in parents) {
+result.addEdge(null, u, parents[u]);
+} else if (init) {
+throw new Error("Input graph is not connected: " + g);
+} else {
+init = true;
+}
+g.incidentEdges(u).forEach(updateNeighbors);
+}
+return result;
+}
+},{"../Graph":33,"cp-data":5}],43:[function(require,module,exports){
+module.exports = tarjan;
+/**
+* This function is an implementation of [Tarjan's algorithm][] which finds
+* all [strongly connected components][] in the directed graph **g**. Each
+* strongly connected component is composed of nodes that can reach all other
+* nodes in the component via directed edges. A strongly connected component
+* can consist of a single node if that node cannot both reach and be reached
+* by any other specific node in the graph. Components of more than one node
+* are guaranteed to have at least one cycle.
+*
+* This function returns an array of components. Each component is itself an
+* array that contains the ids of all nodes in the component.
+*
+* [Tarjan's algorithm]: http://en.wikipedia.org/wiki/Tarjan's_strongly_connected_components_algorithm
+* [strongly connected components]: http://en.wikipedia.org/wiki/Strongly_connected_component
+*
+* @param {Digraph} g the graph to search for strongly connected components
+*/
+function tarjan(g) {
+if (!g.isDirected()) {
+throw new Error("tarjan can only be applied to a directed graph. Bad input: " + g);
+}
+var index = 0,
+stack = [],
+visited = {}, // node id -> { onStack, lowlink, index }
+results = [];
+function dfs(u) {
+var entry = visited[u] = {
+onStack: true,
+lowlink: index,
+index: index++
+};
+stack.push(u);
+g.successors(u).forEach(function(v) {
+if (!(v in visited)) {
+dfs(v);
+entry.lowlink = Math.min(entry.lowlink, visited[v].lowlink);
+} else if (visited[v].onStack) {
+entry.lowlink = Math.min(entry.lowlink, visited[v].index);
+}
+});
+if (entry.lowlink === entry.index) {
+var cmpt = [],
+v;
+do {
+v = stack.pop();
+visited[v].onStack = false;
+cmpt.push(v);
+} while (u !== v);
+results.push(cmpt);
+}
+}
+g.nodes().forEach(function(u) {
+if (!(u in visited)) {
+dfs(u);
+}
+});
+return results;
+}
+},{}],44:[function(require,module,exports){
+module.exports = topsort;
+topsort.CycleException = CycleException;
+/*
+* Given a graph **g**, this function returns an ordered list of nodes such
+* that for each edge `u -> v`, `u` appears before `v` in the list. If the
+* graph has a cycle it is impossible to generate such a list and
+* **CycleException** is thrown.
+*
+* See [topological sorting](https://en.wikipedia.org/wiki/Topological_sorting)
+* for more details about how this algorithm works.
+*
+* @param {Digraph} g the graph to sort
+*/
+function topsort(g) {
+if (!g.isDirected()) {
+throw new Error("topsort can only be applied to a directed graph. Bad input: " + g);
+}
+var visited = {};
+var stack = {};
+var results = [];
+function visit(node) {
+if (node in stack) {
+throw new CycleException();
+}
+if (!(node in visited)) {
+stack[node] = true;
+visited[node] = true;
+g.predecessors(node).forEach(function(pred) {
+visit(pred);
+});
+delete stack[node];
+results.push(node);
+}
+}
+var sinks = g.sinks();
+if (g.order() !== 0 && sinks.length === 0) {
+throw new CycleException();
+}
+g.sinks().forEach(function(sink) {
+visit(sink);
+});
+return results;
+}
+function CycleException() {}
+CycleException.prototype.toString = function() {
+return "Graph has at least one cycle";
+};
+},{}],45:[function(require,module,exports){
+// This file provides a helper function that mixes-in Dot behavior to an
+// existing graph prototype.
+/* jshint -W079 */
+var Set = require("cp-data").Set;
+/* jshint +W079 */
+module.exports = compoundify;
+// Extends the given SuperConstructor with the ability for nodes to contain
+// other nodes. A special node id `null` is used to indicate the root graph.
+function compoundify(SuperConstructor) {
+function Constructor() {
+SuperConstructor.call(this);
+// Map of object id -> parent id (or null for root graph)
+this._parents = {};
+// Map of id (or null) -> children set
+this._children = {};
+this._children[null] = new Set();
+}
+Constructor.prototype = new SuperConstructor();
+Constructor.prototype.constructor = Constructor;
+Constructor.prototype.parent = function(u, parent) {
+this._strictGetNode(u);
+if (arguments.length < 2) {
+return this._parents[u];
+}
+if (u === parent) {
+throw new Error("Cannot make " + u + " a parent of itself");
+}
+if (parent !== null) {
+this._strictGetNode(parent);
+}
+this._children[this._parents[u]].remove(u);
+this._parents[u] = parent;
+this._children[parent].add(u);
+};
+Constructor.prototype.children = function(u) {
+if (u !== null) {
+this._strictGetNode(u);
+}
+return this._children[u].keys();
+};
+Constructor.prototype.addNode = function(u, value) {
+u = SuperConstructor.prototype.addNode.call(this, u, value);
+this._parents[u] = null;
+this._children[u] = new Set();
+this._children[null].add(u);
+return u;
+};
+Constructor.prototype.delNode = function(u) {
+// Promote all children to the parent of the subgraph
+var parent = this.parent(u);
+this._children[u].keys().forEach(function(child) {
+this.parent(child, parent);
+}, this);
+this._children[parent].remove(u);
+delete this._parents[u];
+delete this._children[u];
+return SuperConstructor.prototype.delNode.call(this, u);
+};
+Constructor.prototype.copy = function() {
+var copy = SuperConstructor.prototype.copy.call(this);
+this.nodes().forEach(function(u) {
+copy.parent(u, this.parent(u));
+}, this);
+return copy;
+};
+Constructor.prototype.filterNodes = function(filter) {
+var self = this,
+copy = SuperConstructor.prototype.filterNodes.call(this, filter);
+var parents = {};
+function findParent(u) {
+var parent = self.parent(u);
+if (parent === null || copy.hasNode(parent)) {
+parents[u] = parent;
+return parent;
+} else if (parent in parents) {
+return parents[parent];
+} else {
+return findParent(parent);
+}
+}
+copy.eachNode(function(u) { copy.parent(u, findParent(u)); });
+return copy;
+};
+return Constructor;
+}
+},{"cp-data":5}],46:[function(require,module,exports){
+var Graph = require("../Graph"),
+Digraph = require("../Digraph"),
+CGraph = require("../CGraph"),
+CDigraph = require("../CDigraph");
+exports.decode = function(nodes, edges, Ctor) {
+Ctor = Ctor || Digraph;
+if (typeOf(nodes) !== "Array") {
+throw new Error("nodes is not an Array");
+}
+if (typeOf(edges) !== "Array") {
+throw new Error("edges is not an Array");
+}
+if (typeof Ctor === "string") {
+switch(Ctor) {
+case "graph": Ctor = Graph; break;
+case "digraph": Ctor = Digraph; break;
+case "cgraph": Ctor = CGraph; break;
+case "cdigraph": Ctor = CDigraph; break;
+default: throw new Error("Unrecognized graph type: " + Ctor);
+}
+}
+var graph = new Ctor();
+nodes.forEach(function(u) {
+graph.addNode(u.id, u.value);
+});
+// If the graph is compound, set up children...
+if (graph.parent) {
+nodes.forEach(function(u) {
+if (u.children) {
+u.children.forEach(function(v) {
+graph.parent(v, u.id);
+});
+}
+});
+}
+edges.forEach(function(e) {
+graph.addEdge(e.id, e.u, e.v, e.value);
+});
+return graph;
+};
+exports.encode = function(graph) {
+var nodes = [];
+var edges = [];
+graph.eachNode(function(u, value) {
+var node = {id: u, value: value};
+if (graph.children) {
+var children = graph.children(u);
+if (children.length) {
+node.children = children;
+}
+}
+nodes.push(node);
+});
+graph.eachEdge(function(e, u, v, value) {
+edges.push({id: e, u: u, v: v, value: value});
+});
+var type;
+if (graph instanceof CDigraph) {
+type = "cdigraph";
+} else if (graph instanceof CGraph) {
+type = "cgraph";
+} else if (graph instanceof Digraph) {
+type = "digraph";
+} else if (graph instanceof Graph) {
+type = "graph";
+} else {
+throw new Error("Couldn't determine type of graph: " + graph);
+}
+return { nodes: nodes, edges: edges, type: type };
+};
+function typeOf(obj) {
+return Object.prototype.toString.call(obj).slice(8, -1);
+}
+},{"../CDigraph":30,"../CGraph":31,"../Digraph":32,"../Graph":33}],47:[function(require,module,exports){
+/* jshint -W079 */
+var Set = require("cp-data").Set;
+/* jshint +W079 */
+exports.all = function() {
+return function() { return true; };
+};
+exports.nodesFromList = function(nodes) {
+var set = new Set(nodes);
+return function(u) {
+return set.has(u);
+};
+};
+},{"cp-data":5}],48:[function(require,module,exports){
+var Graph = require("./Graph"),
+Digraph = require("./Digraph");
+// Side-effect based changes are lousy, but node doesn't seem to resolve the
+// requires cycle.
+/**
+* Returns a new directed graph using the nodes and edges from this graph. The
+* new graph will have the same nodes, but will have twice the number of edges:
+* each edge is split into two edges with opposite directions. Edge ids,
+* consequently, are not preserved by this transformation.
+*/
+Graph.prototype.toDigraph =
+Graph.prototype.asDirected = function() {
+var g = new Digraph();
+this.eachNode(function(u, value) { g.addNode(u, value); });
+this.eachEdge(function(e, u, v, value) {
+g.addEdge(null, u, v, value);
+g.addEdge(null, v, u, value);
+});
+return g;
+};
+/**
+* Returns a new undirected graph using the nodes and edges from this graph.
+* The new graph will have the same nodes, but the edges will be made
+* undirected. Edge ids are preserved in this transformation.
+*/
+Digraph.prototype.toGraph =
+Digraph.prototype.asUndirected = function() {
+var g = new Graph();
+this.eachNode(function(u, value) { g.addNode(u, value); });
+this.eachEdge(function(e, u, v, value) {
+g.addEdge(e, u, v, value);
+});
+return g;
+};
+},{"./Digraph":32,"./Graph":33}],49:[function(require,module,exports){
+// Returns an array of all values for properties of **o**.
+exports.values = function(o) {
+var ks = Object.keys(o),
+len = ks.length,
+result = new Array(len),
+i;
+for (i = 0; i < len; ++i) {
+result[i] = o[ks[i]];
+}
+return result;
+};
+},{}],50:[function(require,module,exports){
+module.exports = '0.7.4';
+},{}]},{},[1])
+;