ds.visitors

The ds.visitors module is a collection of visitors on data structures.

breadthFirst(root, callback, [doProcess])

Traverses the nodes of a graph in breadth-first search order, starting at a particular root node. The algorithm extends nodes with a non-enumerable property __hash in order to tell visited from unvisited nodes in cyclic graphs.

See Wikipedia, Breadth-first search for an explanation of this tree or graph traversion algorithm.

Node Structure:

The adjacent nodes of a particular node are expected to be made available via the node's children property (no other assumptions are made on the node structure):

{
  name: "root",
  value: 3,
  children: [
    {
      name: "A",
      value: 2
    },
    {
      name: "B",
      value: 1
    }
  ]
}

Params:

• Object root The designated root node.

• Function callback A callback f(node, path) to be executed upon visiting node, where path is an array of node indexes from root to node.

• Function:Boolean|undefined [doProcess] A function f(node, path) which indicates if a particular node shall be visited or not by returning a truthy or falsy value, respectively, where path is an array of node indexes from root to node.

Throws:

• Error Throws if callback is not a function.

• Error Throws if doProcess is defined and is not a function.

depthFirst(root, callback, [doProcess])

Traverses the nodes of a graph in depth-first search order, starting at a particular root node. The algorithm extends nodes with a non-enumerable property __hash in order to tell visited from unvisited nodes in cyclic graphs.

See Wikipedia, Depth-first search for an explanation of this tree or graph traversion algorithm.

Node Structure:

The adjacent nodes of a particular node are expected to be made available via the node's children property (no other assumptions are made on the node structure):

{
  name: "root",
  value: 3,
  children: [
    {
      name: "A",
      value: 2
    },
    {
      name: "B",
      value: 1
    }
  ]
}

Params:

• Object root The designated root node.

• Function callback A callback f(node, path) to be executed upon visiting node, where path is an array of node indexes from root to node.

• Function:Boolean|undefined [doProcess] A function f(node, path) which indicates if a particular node shall be visited or not by returning a truthy or falsy value, respectively, where path is an array of node indexes from root to node.

Throws:

• Error Throws if callback is not a function.

• Error Throws if doProcess is defined and is not a function.