An intuitive data structure for graphs, implemented using ES6 data structures.
var Graph = require('graphs')
var graph = new Graph()
var a = {name: 'a'}
var b = {name: 'b'}
graph.add(a)
graph.add(b)
graph.link(a, b)
graph.traverse(function(from, to) {
console.log(from.name, 'linked to', to.name)
})
// => a linked to bvar graph = new Graph()
var a = {name: 'a'}
graph.add(a)
graph.has(a) // => true
graph.size // => 1
var b = {name: 'b'}
graph.has(b) // => false
graph.size // => 2
graph.add(b)
graph.has(b) // => truegraph.link(a, b)Linking will also add nodes to the graph.
.to and .from return ES6 Sets of connected nodes.
graph.link(a, b)
graph.from(a) // Set of nodes connected from a
graph.from(a).size // => 1
graph.from(a).has(b) // => true
graph.to(b) // Set of nodes connected to b
graph.to(b).has(a) // => true
graph.from(b).size // => 0graph.unlink(a, b)
graph.from(a).size // => 0- Also removes any links (but not linked nodes).
graph.delete(b).forEachwill even include entirely unlinked nodes.
graph.forEach(function(node) {
console.log('node: %s', node.name)
})graph.traverse will traverse all links from the specified node.
- Arguments to the callback are
from, to - Starts at a node and follows links.
- May visit a node multiple times (depending on how many times it's linked to).
- The callback will always fire with valid
fromandtoparameters. - If startNode is not linked to anything, callback will not fire.
- Will not follow cycles.
graph.traverse(startNode, function(from, to) {
console.log('from: %s', from)
console.log('to: %s', to)
})graph.visit will visit each node that can be reached from the specified node, once.
- Arguments to the callback are
to, from - Will follow links but will not visit any node more than once.
- The
fromargument may not be set ifvisitdidn't follow a link to the current node (e.g. on the first iteration).
graph.visit(startNode, function(node, linkedFrom) {
console.log('node: %s', node)
console.log('linkedFrom: %s', linkedFrom)
})Makes it easy to embed custom logic into your graph.
graph.before('add', function(a,b) {
// execute before add
})
graph.after('add', function(a,b) {
// execute after add
})
graph.guard('add', function(node) {
// prevent add from running if return falsey
})See these libraries for usage information:
MIT