cleargraph
v7.0.0
Published
A library for modeling and traversing graphs
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Cleargraph
Cleargraph is a graph library offering:
- An abstraction over graphs that supports generic data types
- Traversal over successors and predecessors
- Use of user-defined filters on nodes and edges information and traversal
- Strictly-typed implementation
Installation
npm install cleargraph
yarn add cleargraph
Getting started
The nodes and edges in the graph are represented by key-value pairs where the keys are strings,
and the generics N
and E
represent the node value and edge value respectively.
When instantiating the graph, specify the values of N
and E
.
In addition, in order to allow graph serialization, N and E should implement stringify()
.
If it's not implemented, the graph will call its own default serialization method that might not work for complex objects.
Here is an example of N (Node Data) and E (Edge Data) classes:
class Orb { // a node in the graph
name: string;
radius: number;
constructor(name:string, radius:number){
this.name = name;
this.radius = radius;
}
stringify(){ // Add a specific stringify() implementation if your class will not stringify correctly with just JSON.stringiy when serializing the graph
return JSON.stringify({name: this.name, radius: this.radius});
}
}
class OrbRelation{ // an edge in the graph
relationType: string;
proximity: number;
constructor(relationType: string, proximity: number){
this.relationType = relationType;
this.proximity = proximity;
}
stringify(){
return JSON.stringify({relationType: this.relationType, proximity: this.proximity});
}
}
Using these classes to implement a graph:
let g = new Graph<Orb, OrbRelation>();
g.setNode('earth', new Orb('earth', 6371));
g.setNode('moon', new Orb('moon', 1737));
g.setNode('sun', new Orb('sun', 696340));
g.setEdge('moon','earth', new OrbRelation('orbits', 384400));
g.setEdge('earth','sun', new OrbRelation('orbits', 147240000));
Some uses of the graph:
g.node('moon');
// Orb{name: 'moon', radius: 1737}
g.edge('earth', 'sun');
//OrbRelation{relationType: 'orbits', proximity: 147240000}
g.succssors('moon'); // returns the immediate nodes the given node point to
// Map
// {"earth" => Orb} {key: "earth", value: Orb}
// key:"earth"
// value:Orb {name: "earth", radius: 6371}
g.successorsArray('moon'); // returns an array of all the nodes the given node points to *recursively*
// Array(2) [Orb, Orb]
// 0:Orb {name: "earth",radius: 6371}
// 1:Orb {name: "sun", radius: 696340}
g.toposort(); // performs a topological sort on the graph
// Array(3) [Orb, Orb, Orb]
// 0:Orb {name: "moon",radius: 1737}
// 1:Orb {name: "earth",radius: 6371}
// 2:Orb {name: "sun", radius: 696340}
Contributing
Contributions are always welcome, no matter how large or small.
License
Apache license, version 2.0