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https://github.com/jasnell/reasoner
https://github.com/jasnell/reasoner
Last synced: 5 days ago
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- Host: GitHub
- URL: https://github.com/jasnell/reasoner
- Owner: jasnell
- License: apache-2.0
- Created: 2015-07-31T07:19:44.000Z (over 9 years ago)
- Default Branch: master
- Last Pushed: 2017-10-26T05:00:56.000Z (about 7 years ago)
- Last Synced: 2024-04-14T02:20:48.848Z (7 months ago)
- Language: JavaScript
- Size: 52.7 KB
- Stars: 10
- Watchers: 4
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-starred - jasnell/reasoner - (others)
README
## Reasoner
A simple linked data reasoner...
This module began life as part of the ActivityStrea.ms implementation
(http://github.com/jasnell/activitystrea.ms).
### Requirements:
This module requires Node.js 4.0.0 and uses ES6 language features.
### Install:
```
npm install reasoner
```
### Example:
```
const rdf = require('linkeddata-vocabs').rdf;
const Reasoner = require('reasoner');
const Graph = Reasoner.Graph;
const graph = new Graph();
graph.add({
subject: 'http://example.org/foo',
predicate: rdf.type,
object: 'http://example.org/bar'
});
graph.add({
subject: 'http://example.org/foo',
predicate: rdf.type,
object: 'http://example.org/baz'
});
graph.add({
subject: 'http://example.org/foo',
predicate: rdfs.subClassOf,
object: 'http://example.org/boo'
});
graph.add({
subject: 'http://example.org/boo',
predicate: rdfs.subClassOf,
object: 'http://example.org/aaa'
});
graph.add({
subject: 'http://example.org/aaa',
predicate: rdfs.subClassOf,
object: 'http://example.org/ccc'
});
graph.add({
subject: 'http://example.org/bar',
predicate: rdfs.subClassOf,
object: 'http://example.org/aaa'
});
graph.add({
subject: 'http://example.org/bbb',
predicate: rdfs.subClassOf,
object: 'http://example.org/aaa'
});
const reasoner = new Reasoner(graph);
const node = reasoner.node('http://example.org/foo');
node.is('http://example.org/bar'); // true
node.is('http://example.org/boo'); // true
node.is('http://example.org/aaa'); // true
node.is('http://example.org/ccc'); // true
node.is('http://example.org/bbb'); // false
```
## API
### Constructor: `Reasoner([graph])`
Creates a new Reasoner. Either a single `Reasoner.Graph` instance, or an array
of `Reasoner.Graph` instances can be provided to the constructor to be bound
automatically when the Reasoner is created.
#### Property: ` Reasoner.prototype.size`
The total number of triples known to the Reasoner.
#### Method: `Reasoner.prototype.bind(graph)`
Binds a single `Reasoner.Graph` instance to the Reasoner.
#### Method: ` Reasoner.prototype.node(uri)`
Returns a `Reasoner.Node` instance. A Node represents a single subject known to
the Reasoner.
#### Method: ` Reasoner.prototype.literal(value[, options])`
Utility method that creates new `Reasoner.Literal`
### Constructor: `Reasoner.Graph()`
Creates a new `Reasoner.Graph` instance. A Graph is essentially a thin wrapper
around an `N3.Store` object.
#### Property : ` Reasoner.Graph.prototype.size`
Returns the total number of triples known to the Graph.
#### Method: `Reasoner.Graph.prototype.add(triple)`
Adds a single triple to the Graph. The argument is an object with three
properties: `subject`, `predicate` and `object`.
```javascript
const Graph = require('reasoner').Graph;
const graph = new Graph();
graph.add({
subject: 'http://example.org/foo',
predicate: 'http://example.org/bar',
object: 'http://example.org/baz'
});
```
#### Method: `Reasoner.Graph.prototype.merge(graph)`
Merge the specified Graph into this Graph.
#### Method: `Reasoner.Graph.prototype.find(triple)`
Search the Graph for triples matching the specified pattern.
```javascript
const Graph = require('reasoner').Graph;
const graph = new Graph();
graph.add({
subject: 'http://example.org/foo',
predicate: 'http://example.org/bar',
object: 'http://example.org/baz'
});
const triples = graph.find({subject:'http://example.org/foo'});
for (const triple of triples) {
console.log(triple);
}
```
### Object: `Reasoner.Node`
The `Reasoner.Node` object provides access to explicit and inferred information
about a single subject known to the Reasoner.
```javascript
const Reasoner = require('reasoner');
const Graph = Reasoner.Graph;
const graph = new Graph();
graph.add({
subject: 'http://example.org/foo',
predicate: 'http://example.org/bar',
object: 'http://example.org/baz'
});
const reasoner = new Reasoner(graph);
const node = reasoner.node('http://example.org/foo');
// ...
```
#### Property: `Reasoner.Node.prototype.id`
The Subject URI
#### Method: `Reasoner.Node.prototype.findInbound(predicate)`
Searches for all triples known to the Reasoner for which this node is the
*object*.
#### Method: `Reasoner.Node.prototype.find(predicate)`
Searches for all triples known to the Reasoner for which this node is the
*subject*.
#### Method: `Reasoner.Node.prototype.literal(predicate)`
Searches for literal values with the specified predicate.
```javascript
var literals = node.literal('http://example.org/label');
for (let literal of literals) {
console.log(literal.valueOf());
console.log(literal.type);
console.log(literal.language);
};
```
#### Property: `Reasoner.Node.prototype.types`
The collection of `rdf:type` explicitly defined for this subject.
#### Property: `Reasoner.Node.prototype.subProperties`
A listing of `Reasoner.Node` objects representing other subjects defined as
`rdfs:subPropertyOf` this subject.
#### Property: `Reasoner.Node.prototype.subClasses`
A listing of `Reasoner.Node` objects representing other
subjects defined as `rdfs:subClassOf` this subject.
#### Property: `Reasoner.Node.prototype.superProperties`
A listing of `Reasoner.Node` objects representing other
subjects for which this node can be considered a sub-property.
#### Property: `Reasoner.Node.prototype.superClasses`
A listing of `Reasoner.Node` objects representing other
subjects for which this node can be considered a sub-class.
#### Method: `Reasoner.Node.prototype.is(type)`
Returns `true` if this subject can be considered to be an instance of the
specified type. Specifically, this will return `true` if:
1. It has `rdf:type` `type`
2. One of it's `rdf:type`'s is `type`
3. It has `rdfs:subClassOf` `type`
4. One of it's superClasses is `type`
5. It has `rdfs:subPropertyOf` `type`
6. One of it's superProperties is `type`
### Object: `Reasoner.Literal`
Represents a literal value.
#### Method: `Reasoner.Literal.prototype.valueOf()`
Returns the value of the literal.
#### Property: ` Reasoner.Literal.prototype.type`
A `Reasoner.Node` representing the Literal type.
#### Property: ` Reasoner.Literal.prototype.language`
A `LanguageTag` representing the Literal language. (The `LanguageTag` object is
provided by the `rfc5646` module in npm)