1 files changed, 69 insertions, 0 deletions
diff --git a/node_modules/toposort/index.js b/node_modules/toposort/index.js
new file mode 100644
index 00000000..c9897e71
--- /dev/null
+++ b/node_modules/toposort/index.js
@@ -0,0 +1,69 @@
+
+/**
+ * Topological sorting function
+ *
+ * @param {Array} edges
+ * @returns {Array}
+ */
+
+module.exports = function(edges){
+  return toposort(uniqueNodes(edges), edges)
+}
+
+module.exports.array = toposort
+
+function toposort(nodes, edges) {
+  var cursor = nodes.length
+    , sorted = new Array(cursor)
+    , visited = {}
+    , i = cursor
+
+  while (i--) {
+    if (!visited[i]) visit(nodes[i], i, [])
+  }
+
+  return sorted
+
+  function visit(node, i, predecessors) {
+    if(predecessors.indexOf(node) >= 0) {
+      var nodeRep 
+      try {
+        nodeRep = ", node was:" + JSON.stringify(node)
+      } catch(e) {
+        nodeRep = ""
+      }
+      throw new Error('Cyclic dependency' + nodeRep)
+    }
+
+    if (!~nodes.indexOf(node)) {
+      throw new Error('Found unknown node. Make sure to provided all involved nodes. Unknown node: '+JSON.stringify(node))
+    }
+
+    if (visited[i]) return;
+    visited[i] = true
+
+    // outgoing edges
+    var outgoing = edges.filter(function(edge){
+      return edge[0] === node
+    })
+    if (i = outgoing.length) {
+      var preds = predecessors.concat(node)
+      do {
+        var child = outgoing[--i][1]
+        visit(child, nodes.indexOf(child), preds)
+      } while (i)
+    }
+
+    sorted[--cursor] = node
+  }
+}
+
+function uniqueNodes(arr){
+  var res = []
+  for (var i = 0, len = arr.length; i < len; i++) {
+    var edge = arr[i]
+    if (res.indexOf(edge[0]) < 0) res.push(edge[0])
+    if (res.indexOf(edge[1]) < 0) res.push(edge[1])
+  }
+  return res
+}