README
js-graph
js-graph
is a javascript library for storing arbitrary data in mathematical (di)graphs,
as well as traversing and analyzing them in various ways. It was originally created to
track dependencies between options and modules. It is written in ECMAScript 6, but
auto-generated ECMAScript 5 versions are shipped with it.
If you want to run this library in an ECMAScript 5 context, it depends on the Babel ES6 polyfill. For your convenience, a version is provided with this polyfill already baked in, but you also have the option of providing it yourself.
Feedback of any kind (questions, issues, pull requests) is greatly appreciated.
Files
The dist
directory offers different files for use in different circumstances.
Use the following table to determine which file to use in your situation.
File | Description |
---|---|
js‑graph.es6.js |
for use in an ECMAScript 6 context, e.g., a modern browser or transpiler |
js‑graph.js ,js‑graph.min.js |
requires you to load the Babel polyfill yourself |
js‑graph.full.js ,js‑graph.full.min.js |
already includes the Babel polyfill |
If you don't know which you need, you probably want js-graph.full.min.js
, because it will work out-of-the-box.
But it is generally more elegant to load the polyfill yourself, especially if you use other libraries that also
depend on it.
API Documentation
- JsGraph
- instance
- .addNewVertex(key, value)
- .setVertex(key, value)
- .ensureVertex(key, value)
- .addVertex(key, value)
- .removeExistingVertex(key)
- .destroyExistingVertex(key)
- .removeVertex(key)
- .destroyVertex(key)
- .vertexCount() ⇒
number
- .hasVertex(key) ⇒
boolean
- .vertexValue(key) ⇒
*
- .addNewEdge(from, to, value)
- .createNewEdge(from, to, value)
- .setEdge(from, to, value)
- .spanEdge(from, to, value)
- .addEdge(from, to, value)
- .ensureEdge(from, to, value)
- .createEdge(from, to, value)
- .removeExistingEdge(from, to)
- .removeEdge(from, to)
- .edgeCount() ⇒
number
- .hasEdge(from, to) ⇒
boolean
- .edgeValue(from, to) ⇒
*
- .vertices() ⇒
Iterator.<string, *>
- .@@iterator() ⇒
Iterator.<string, *>
- .edges() ⇒
Iterator.<string, string, *>
- .verticesFrom(from) ⇒
Iterator.<string, *, *>
- .verticesTo(to) ⇒
Iterator.<string, *, *>
- .verticesWithPathFrom(from) ⇒
Iterator.<string, *>
- .verticesWithPathTo(to) ⇒
Iterator.<string, *>
- .vertices_topologically() ⇒
Iterator.<string, *>
- .clearEdges()
- .clear()
- .equals(other, [eq]) ⇒
boolean
- .hasCycle() ⇒
boolean
- .hasPath(from, to) ⇒
boolean
- .clone([tr]) ⇒
JsGraph
- .transitiveReduction([tr]) ⇒
JsGraph
- static
- .VertexExistsError ⇐
Error
- .vertices :
Set.<{key: string, value}>
- .vertices :
- .VertexNotExistsError ⇐
Error
- .vertices :
Set.<{key: string}>
- .vertices :
- .EdgeExistsError ⇐
Error
- .edges :
Set.<{from: string, to: string, value}>
- .edges :
- .EdgeNotExistsError ⇐
Error
- .edges :
Set.<{from: string, to: string}>
- .edges :
- .HasConnectedEdgesError ⇐
Error
- .key :
string
- .key :
- .CycleError ⇐
Error
- .cycle :
Array.<string>
- .cycle :
JsGraph
The main class of this library, to be used for representing a mathematical (di)graph.
jsGraph.addNewVertex(key, value)
Add a new vertex to this graph.
Param | Type | Description |
---|---|---|
key | string |
the key with which to refer to this new vertex |
value | * |
the value to store in this new vertex |
Throws:
VertexExistsError
if a vertex with this key already exists
jsGraph.setVertex(key, value)
Set the value of an existing vertex in this graph.
Param | Type | Description |
---|---|---|
key | string |
the key belonging to the vertex |
value | * |
the value to store in this vertex |
Throws:
VertexNotExistsError
if a vertex with this key does not exist
jsGraph.ensureVertex(key, value)
Make sure a vertex with a specific key exists in this graph. If it already exists, nothing is done. If it does not yet exist, a new vertex is added with the given value.
Param | Type | Description |
---|---|---|
key | string |
the key for the vertex |
value | * |
the value to store if a new vertex is added |
jsGraph.addVertex(key, value)
Add a new vertex to this graph. If a vertex with this key already exists, the value of that vertex is overwritten.
Param | Type | Description |
---|---|---|
key | string |
the key with which to refer to this new vertex |
value | * |
the value to store in this new vertex |
jsGraph.removeExistingVertex(key)
Remove an existing vertex from this graph.
Param | Type | Description |
---|---|---|
key | string |
the key of the vertex to remove |
Throws:
VertexNotExistsError
if a vertex with this key does not existHasConnectedEdgesError
if there are still edges connected to this vertex
jsGraph.destroyExistingVertex(key)
Remove an existing vertex from this graph, as well as all edges connected to it.
Param | Type | Description |
---|---|---|
key | string |
the key of the vertex to remove |
Throws:
VertexNotExistsError
if a vertex with this key does not exist
jsGraph.removeVertex(key)
Remove an existing vertex from this graph. If a vertex with this key does not exist, nothing happens.
Param | Type | Description |
---|---|---|
key | string |
the key of the vertex to remove |
Throws:
HasConnectedEdgesError
if there are still edges connected to this vertex
jsGraph.destroyVertex(key)
Remove a vertex from this graph, as well as all edges connected to it. If a vertex with this key does not exist, nothing happens.
Param | Type | Description |
---|---|---|
key | string |
the key of the vertex to remove |
number
jsGraph.vertexCount() ⇒ Returns: number
- the number of vertices in the whole graph
boolean
jsGraph.hasVertex(key) ⇒ Ask whether a vertex with a given key exists.
Param | Type | Description |
---|---|---|
key | string |
the key to query |
Returns: boolean
- whether there is a vertex with the given key
*
jsGraph.vertexValue(key) ⇒ Get the value associated with the vertex of a given key.
Param | Type | Description |
---|---|---|
key | string |
the key to query |
Returns: *
- the value associated with the vertex of the given key.
Note that a return value of undefined
can mean
- that there is no such vertex, or
- that the stored value is actually
undefined
.
Use hasVertex to distinguish these cases.
jsGraph.addNewEdge(from, to, value)
Add a new edge to this graph.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
value | * |
the value to store in this new edge |
Throws:
EdgeExistsError
if an edge betweenfrom
andto
already existsVertexNotExistsError
if thefrom
and/orto
vertices do not yet exist in the graph
jsGraph.createNewEdge(from, to, value)
Add a new edge to this graph. If the from
and/or to
vertices do not yet exist
in the graph, they are implicitly added with an undefined
value.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
value | * |
the value to store in this new edge |
Throws:
EdgeExistsError
if an edge betweenfrom
andto
already exists
jsGraph.setEdge(from, to, value)
Set the value of an existing edge in this graph.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
value | * |
the value to store in this edge |
Throws:
EdgeNotExistsError
if an edge betweenfrom
andto
does not yet exist
jsGraph.spanEdge(from, to, value)
Make sure an edge between the from
and to
vertices in this graph.
If one already exists, nothing is done.
If one does not yet exist, a new edge is added with the given value.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
value | * |
the value to store if a new edge is added |
Throws:
VertexNotExistsError
if thefrom
and/orto
vertices do not yet exist in the graph
jsGraph.addEdge(from, to, value)
Add a new edge to this graph. If an edge between from
and to
already exists,
the value of that edge is overwritten.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
value | * |
the value to store in this new edge |
Throws:
VertexNotExistsError
if thefrom
and/orto
vertices do not yet exist in the graph
jsGraph.ensureEdge(from, to, value)
Make sure an edge between the from
and to
vertices exists in this graph.
If it already exists, nothing is done.
If it does not yet exist, a new edge is added with the given value.
If the from
and/or to
vertices do not yet exist
in the graph, they are implicitly added with an undefined
value.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
value | * |
the value to store if a new edge is added |
jsGraph.createEdge(from, to, value)
Add a new edge to this graph. If an edge between the from
and to
vertices already exists, the value of that edge is overwritten.
If the from
and/or to
vertices do not yet exist
in the graph, they are implicitly added with an undefined
value.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
value | * |
the value to store if a new edge is added |
jsGraph.removeExistingEdge(from, to)
Remove an existing edge from this graph.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
Throws:
EdgeNotExistsError
if an edge between thefrom
andto
vertices doesn't exist
jsGraph.removeEdge(from, to)
Remove an edge from this graph.
If an edge between the from
and to
vertices doesn't exist, nothing happens.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
number
jsGraph.edgeCount() ⇒ Returns: number
- the number of edges in the whole graph
boolean
jsGraph.hasEdge(from, to) ⇒ Ask whether an edge between given from
and to
vertices exist.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
Returns: boolean
- whether there is an edge between the given from
and to
vertices
*
jsGraph.edgeValue(from, to) ⇒ Get the value associated with the edge between given from
and to
vertices.
Param | Type | Description |
---|---|---|
from | string |
the key for the originating vertex |
to | string |
the key for the terminating vertex |
Returns: *
- the value associated with the edge between the given from
and to
vertices
Note that a return value of undefined
can mean
- that there is no such edge, or
- that the stored value is actually
undefined
.
Use hasEdge to distinguish these cases.
Iterator.<string, *>
jsGraph.vertices() ⇒ Iterate over all vertices of the graph, in no particular order.
Returns: Iterator.<string, *>
- an object conforming to the ES6 iterator protocol
Example
for (var it = jsGraph.vertices(), keyVal = it.next(); !it.done;) {
var key = keyVal[0],
value = keyVal[1];
// iterates over all vertices of the graph
}
Example
// in ECMAScript 6, you can use a for..of loop
for (let [key, value] of jsGraph.vertices()) {
// iterates over all vertices of the graph
}
See: @@iterator
Iterator.<string, *>
jsGraph.@@iterator() ⇒ A JsGraph object is itself iterable, and serves as a short notation in ECMAScript 6 to iterate over all vertices in the graph, in no particular order.
Returns: Iterator.<string, *>
- an object conforming to the ES6 iterator protocol
Example
for (let [key, value] of jsGraph) {
// iterates over all vertices of the graph
}
See: vertices
Iterator.<string, string, *>
jsGraph.edges() ⇒ Iterate over all edges of the graph, in no particular order.
Returns: Iterator.<string, string, *>
- an object conforming to the ES6 iterator protocol
Example
for (var it = jsGraph.edges(), fromToVal = it.next(); !it.done;) {
var from = fromToVal[0],
to = fromToVal[1],
value = fromToVal[2];
// iterates over all edges of the graph
}
Example
// in ECMAScript 6, you can use a for..of loop
for (let [from, to, value] of jsGraph.edges()) {
// iterates over all vertices of the graph
}
Iterator.<string, *, *>
jsGraph.verticesFrom(from) ⇒ Iterate over the outgoing edges of a given vertex in the graph, in no particular order.
Param | Type | Description |
---|---|---|
from | string |
the key of the vertex to take the outgoing edges from |
Throws:
VertexNotExistsError
if a vertex with the givenfrom
key does not exist
Returns: Iterator.<string, *, *>
- an object conforming to the ES6 iterator protocol
Example
for (var it = jsGraph.verticesFrom(from), toVertexEdge = it.next(); !it.done;) {
var to = toVertexEdge[0],
vertexValue = toVertexEdge[1],
edgeValue = toVertexEdge[2];
// iterates over all outgoing vertices of the `from` vertex
}
Example
// in ECMAScript 6, you can use a for..of loop
for (let [to, vertexValue, edgeValue] of jsGraph.verticesFrom(from)) {
// iterates over all outgoing edges of the `from` vertex
}
Iterator.<string, *, *>
jsGraph.verticesTo(to) ⇒ Iterate over the incoming edges of a given vertex in the graph, in no particular order.
Param | Type | Description |
---|---|---|
to | string |
the key of the vertex to take the incoming edges from |
Throws:
VertexNotExistsError
if a vertex with the givento
key does not exist
Returns: Iterator.<string, *, *>
- an object conforming to the ES6 iterator protocol
Example
for (var it = jsGraph.verticesTo(to), fromVertexEdge = it.next(); !it.done;) {
var from = fromVertexEdge[0],
vertexValue = fromVertexEdge[1],
edgeValue = fromVertexEdge[2];
// iterates over all outgoing vertices of the `from` vertex
}
Example
// in ECMAScript 6, you can use a for..of loop
for (let [from, vertexValue, edgeValue] of jsGraph.verticesTo(to)) {
// iterates over all incoming edges of the `to` vertex
}
Iterator.<string, *>
jsGraph.verticesWithPathFrom(from) ⇒ Iterate over all vertices reachable from a given vertex in the graph, in no particular order.
Param | Type | Description |
---|---|---|
from | string |
the key of the vertex to take the reachable vertices from |
Throws:
VertexNotExistsError
if a vertex with the givenfrom
key does not exist
Returns: Iterator.<string, *>
- an object conforming to the ES6 iterator protocol
Example
for (var it = jsGraph.verticesWithPathFrom(from), keyValue = it.next(); !it.done;) {
var key = keyValue[0],
value = keyValue[1];
// iterates over all vertices reachable from `from`
}
Example
// in ECMAScript 6, you can use a for..of loop
for (let [key, value] of jsGraph.verticesWithPathFrom(from)) {
// iterates over all vertices reachable from `from`
}
Iterator.<string, *>
jsGraph.verticesWithPathTo(to) ⇒ Iterate over all vertices from which a given vertex in the graph can be reached, in no particular order.
Param | Type | Description |
---|---|---|
to | string |
the key of the vertex to take the reachable vertices from |
Throws:
VertexNotExistsError
if a vertex with the givento
key does not exist
Returns: Iterator.<string, *>
- an object conforming to the ES6 iterator protocol
Example
for (var it = jsGraph.verticesWithPathTo(to), keyValue = it.next(); !it.done;) {
var key = keyValue[0],
value = keyValue[1];
// iterates over all vertices from which `to` can be reached
}
Example
// in ECMAScript 6, you can use a for..of loop
for (let [key, value] of jsGraph.verticesWithPathTo(to)) {
// iterates over all vertices from which `to` can be reached
}
Iterator.<string, *>
jsGraph.vertices_topologically() ⇒ Iterate over all vertices of the graph in topological order.
Returns: Iterator.<string, *>
- an object conforming to the ES6 iterator protocol
Example
for (var it = jsGraph.vertices_topologically(), keyVal = it.next(); !it.done;) {
var key = keyVal[0],
value = keyVal[1];
// iterates over all vertices of the graph in topological order
}
Example
// in ECMAScript 6, you can use a for..of loop
for (let [key, value] of jsGraph.vertices_topologically()) {
// iterates over all vertices of the graph in topological order
}
jsGraph.clearEdges()
Remove all edges from the graph, but leave the vertices intact.
jsGraph.clear()
Remove all edges and vertices from the graph, putting it back in its initial state.
boolean
jsGraph.equals(other, [eq]) ⇒ Ask whether this graph and another graph are equal. Two graphs are equal if they have the same vertices and the same edges.
Param | Type | Description |
---|---|---|
other | JsGraph |
the other graph to compare this one to |
[eq] | function |
a custom equality function for stored values; defaults to === comparison; The first two arguments are the two values to compare. If they are vertex values, the third argument is the vertex key. If they are edge values, the third and fourth argument are the from and to keys respectively. (So you can test the fourth argument to distinguish the two cases.) |
Returns: boolean
- true
if the two graphs are equal; false
otherwise
boolean
jsGraph.hasCycle() ⇒ Test whether the graph contains a directed cycle.
Returns: boolean
- false
, if there is no cycle; a truthy value if there is a cycle
(not necessarily true
; future versions of the library might return
a description of the cycle)
boolean
jsGraph.hasPath(from, to) ⇒ Test whether there is a directed path between a given pair of keys.
Param | Type | Description |
---|---|---|
from | string |
the originating vertex |
to | string |
the terminating vertex |
Returns: boolean
- false
, if there is no such path; a truthy value if there is such a path
(not necessarily true
; future versions of the library might return
a description of the path)
JsGraph
jsGraph.clone([tr]) ⇒ Create a clone of this graph.
Param | Type | Description |
---|---|---|
[tr] | function |
a custom transformation function for stored values; defaults to the identity function; The first argument is the value to clone. If it is a vertex value, the third argument is the vertex key. If it is an edge value, the third and fourth argument are the from and to keys respectively. (So you can test the fourth argument to distinguish the two cases.) |
Returns: JsGraph
- a clone of this graph
JsGraph
jsGraph.transitiveReduction([tr]) ⇒ Create a clone of this graph, but without any transitive edges.
Param | Type | Description |
---|---|---|
[tr] | function |
a custom transformation function for stored values; defaults to the identity function; The first argument is the value to clone. If it is a vertex value, the third argument is the vertex key. If it is an edge value, the third and fourth argument are the from and to keys respectively. (So you can test the fourth argument to distinguish the two cases.) |
Returns: JsGraph
- a clone of this graph
Error
JsGraph.VertexExistsError ⇐ This type of error is thrown when specific vertices are expected not to exist, but do.
Extends: Error
Set.<{key: string, value}>
vertexExistsError.vertices : the set of relevant vertices
Error
JsGraph.VertexNotExistsError ⇐ This type of error is thrown when specific vertices are expected to exist, but don't.
Extends: Error
Set.<{key: string}>
vertexNotExistsError.vertices : the set of relevant vertices
Error
JsGraph.EdgeExistsError ⇐ This type of error is thrown when specific edges are expected not to exist, but do.
Extends: Error
Set.<{from: string, to: string, value}>
edgeExistsError.edges : the set of relevant edges
Error
JsGraph.EdgeNotExistsError ⇐ This type of error is thrown when specific edges are expected to exist, but don't.
Extends: Error
Set.<{from: string, to: string}>
edgeNotExistsError.edges : the set of relevant edges
Error
JsGraph.HasConnectedEdgesError ⇐ This type of error is thrown when a vertex is expected not to have connected edges, but does.
Extends: Error
string
hasConnectedEdgesError.key : the key of the relevant vertex
Error
JsGraph.CycleError ⇐ This type of error is thrown when a graph is expected not to have a directed cycle, but does.
Extends: Error
Array.<string>
cycleError.cycle : the vertices involved in the cycle