n3/lib/N3DataFactory.js

Lightning fast, asynchronous, streaming Turtle / N3 / RDF library.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = exports.Variable = exports.Triple = exports.Term = exports.Quad = exports.NamedNode = exports.Literal = exports.DefaultGraph = exports.BlankNode = void 0;
exports.escapeQuotes = escapeQuotes;
exports.fromQuad = fromQuad;
exports.fromTerm = fromTerm;
exports.termFromId = termFromId;
exports.termToId = termToId;
exports.unescapeQuotes = unescapeQuotes;
var _IRIs = _interopRequireDefault(require("./IRIs"));
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
// N3.js implementations of the RDF/JS core data types
// See http://rdf.js.org/data-model-spec/

const {
  rdf,
  xsd
} = _IRIs.default;

// eslint-disable-next-line prefer-const
let DEFAULTGRAPH;
let _blankNodeCounter = 0;
const escapedLiteral = /^"(.*".*)(?="[^"]*$)/;

// ## DataFactory singleton
const DataFactory = {
  namedNode,
  blankNode,
  variable,
  literal,
  defaultGraph,
  quad,
  triple: quad,
  fromTerm,
  fromQuad
};
var _default = exports.default = DataFactory; // ## Term constructor
class Term {
  constructor(id) {
    this.id = id;
  }

  // ### The value of this term
  get value() {
    return this.id;
  }

  // ### Returns whether this object represents the same term as the other
  equals(other) {
    // If both terms were created by this library,
    // equality can be computed through ids
    if (other instanceof Term) return this.id === other.id;
    // Otherwise, compare term type and value
    return !!other && this.termType === other.termType && this.value === other.value;
  }

  // ### Implement hashCode for Immutable.js, since we implement `equals`
  // https://immutable-js.com/docs/v4.0.0/ValueObject/#hashCode()
  hashCode() {
    return 0;
  }

  // ### Returns a plain object representation of this term
  toJSON() {
    return {
      termType: this.termType,
      value: this.value
    };
  }
}

// ## NamedNode constructor
exports.Term = Term;
class NamedNode extends Term {
  // ### The term type of this term
  get termType() {
    return 'NamedNode';
  }
}

// ## Literal constructor
exports.NamedNode = NamedNode;
class Literal extends Term {
  // ### The term type of this term
  get termType() {
    return 'Literal';
  }

  // ### The text value of this literal
  get value() {
    return this.id.substring(1, this.id.lastIndexOf('"'));
  }

  // ### The language of this literal
  get language() {
    // Find the last quotation mark (e.g., '"abc"@en-us')
    const id = this.id;
    let atPos = id.lastIndexOf('"') + 1;
    const dirPos = id.lastIndexOf('--');
    // If "@" it follows, return the remaining substring; empty otherwise
    return atPos < id.length && id[atPos++] === '@' ? (dirPos > atPos ? id.substr(0, dirPos) : id).substr(atPos).toLowerCase() : '';
  }

  // ### The direction of this literal
  get direction() {
    // Find the last double dash after the closing quote (e.g., '"abc"@en-us--ltr')
    const id = this.id;
    const endPos = id.lastIndexOf('"');
    const dirPos = id.lastIndexOf('--');
    return dirPos > endPos && dirPos + 2 < id.length ? id.substr(dirPos + 2).toLowerCase() : '';
  }

  // ### The datatype IRI of this literal
  get datatype() {
    return new NamedNode(this.datatypeString);
  }

  // ### The datatype string of this literal
  get datatypeString() {
    // Find the last quotation mark (e.g., '"abc"^^http://ex.org/types#t')
    const id = this.id,
      dtPos = id.lastIndexOf('"') + 1;
    const char = dtPos < id.length ? id[dtPos] : '';
    // If "^" it follows, return the remaining substring
    return char === '^' ? id.substr(dtPos + 2) :
    // If "@" follows, return rdf:langString or rdf:dirLangString; xsd:string otherwise
    char !== '@' ? xsd.string : id.indexOf('--', dtPos) > 0 ? rdf.dirLangString : rdf.langString;
  }

  // ### Returns whether this object represents the same term as the other
  equals(other) {
    // If both literals were created by this library,
    // equality can be computed through ids
    if (other instanceof Literal) return this.id === other.id;
    // Otherwise, compare term type, value, language, and datatype
    return !!other && !!other.datatype && this.termType === other.termType && this.value === other.value && this.language === other.language && (this.direction === other.direction || this.direction === '' && !other.direction) && this.datatype.value === other.datatype.value;
  }
  toJSON() {
    return {
      termType: this.termType,
      value: this.value,
      language: this.language,
      direction: this.direction,
      datatype: {
        termType: 'NamedNode',
        value: this.datatypeString
      }
    };
  }
}

// ## BlankNode constructor
exports.Literal = Literal;
class BlankNode extends Term {
  constructor(name) {
    super(`_:${name}`);
  }

  // ### The term type of this term
  get termType() {
    return 'BlankNode';
  }

  // ### The name of this blank node
  get value() {
    return this.id.substr(2);
  }
}
exports.BlankNode = BlankNode;
class Variable extends Term {
  constructor(name) {
    super(`?${name}`);
  }

  // ### The term type of this term
  get termType() {
    return 'Variable';
  }

  // ### The name of this variable
  get value() {
    return this.id.substr(1);
  }
}

// ## DefaultGraph constructor
exports.Variable = Variable;
class DefaultGraph extends Term {
  constructor() {
    super('');
    return DEFAULTGRAPH || this;
  }

  // ### The term type of this term
  get termType() {
    return 'DefaultGraph';
  }

  // ### Returns whether this object represents the same term as the other
  equals(other) {
    // If both terms were created by this library,
    // equality can be computed through strict equality;
    // otherwise, compare term types.
    return this === other || !!other && this.termType === other.termType;
  }
}

// ## DefaultGraph singleton
exports.DefaultGraph = DefaultGraph;
DEFAULTGRAPH = new DefaultGraph();

// ### Constructs a term from the given internal string ID
// The third 'nested' parameter of this function is to aid
// with recursion over nested terms. It should not be used
// by consumers of this library.
// See https://github.com/rdfjs/N3.js/pull/311#discussion_r1061042725
function termFromId(id, factory, nested) {
  factory = factory || DataFactory;

  // Falsy value or empty string indicate the default graph
  if (!id) return factory.defaultGraph();

  // Identify the term type based on the first character
  switch (id[0]) {
    case '?':
      return factory.variable(id.substr(1));
    case '_':
      return factory.blankNode(id.substr(2));
    case '"':
      // Shortcut for internal literals
      if (factory === DataFactory) return new Literal(id);
      // Literal without datatype or language
      if (id[id.length - 1] === '"') return factory.literal(id.substr(1, id.length - 2));
      // Literal with datatype or language
      const endPos = id.lastIndexOf('"', id.length - 1);
      let languageOrDatatype;
      if (id[endPos + 1] === '@') {
        languageOrDatatype = id.substr(endPos + 2);
        const dashDashIndex = languageOrDatatype.lastIndexOf('--');
        if (dashDashIndex > 0 && dashDashIndex < languageOrDatatype.length) {
          languageOrDatatype = {
            language: languageOrDatatype.substr(0, dashDashIndex),
            direction: languageOrDatatype.substr(dashDashIndex + 2)
          };
        }
      } else {
        languageOrDatatype = factory.namedNode(id.substr(endPos + 3));
      }
      return factory.literal(id.substr(1, endPos - 1), languageOrDatatype);
    case '[':
      id = JSON.parse(id);
      break;
    default:
      if (!nested || !Array.isArray(id)) {
        return factory.namedNode(id);
      }
  }
  return factory.quad(termFromId(id[0], factory, true), termFromId(id[1], factory, true), termFromId(id[2], factory, true), id[3] && termFromId(id[3], factory, true));
}

// ### Constructs an internal string ID from the given term or ID string
// The third 'nested' parameter of this function is to aid
// with recursion over nested terms. It should not be used
// by consumers of this library.
// See https://github.com/rdfjs/N3.js/pull/311#discussion_r1061042725
function termToId(term, nested) {
  if (typeof term === 'string') return term;
  if (term instanceof Term && term.termType !== 'Quad') return term.id;
  if (!term) return DEFAULTGRAPH.id;

  // Term instantiated with another library
  switch (term.termType) {
    case 'NamedNode':
      return term.value;
    case 'BlankNode':
      return `_:${term.value}`;
    case 'Variable':
      return `?${term.value}`;
    case 'DefaultGraph':
      return '';
    case 'Literal':
      return `"${term.value}"${term.language ? `@${term.language}${term.direction ? `--${term.direction}` : ''}` : term.datatype && term.datatype.value !== xsd.string ? `^^${term.datatype.value}` : ''}`;
    case 'Quad':
      const res = [termToId(term.subject, true), termToId(term.predicate, true), termToId(term.object, true)];
      if (term.graph && term.graph.termType !== 'DefaultGraph') {
        res.push(termToId(term.graph, true));
      }
      return nested ? res : JSON.stringify(res);
    default:
      throw new Error(`Unexpected termType: ${term.termType}`);
  }
}

// ## Quad constructor
class Quad extends Term {
  constructor(subject, predicate, object, graph) {
    super('');
    this._subject = subject;
    this._predicate = predicate;
    this._object = object;
    this._graph = graph || DEFAULTGRAPH;
  }

  // ### The term type of this term
  get termType() {
    return 'Quad';
  }
  get subject() {
    return this._subject;
  }
  get predicate() {
    return this._predicate;
  }
  get object() {
    return this._object;
  }
  get graph() {
    return this._graph;
  }

  // ### Returns a plain object representation of this quad
  toJSON() {
    return {
      termType: this.termType,
      subject: this._subject.toJSON(),
      predicate: this._predicate.toJSON(),
      object: this._object.toJSON(),
      graph: this._graph.toJSON()
    };
  }

  // ### Returns whether this object represents the same quad as the other
  equals(other) {
    return !!other && this._subject.equals(other.subject) && this._predicate.equals(other.predicate) && this._object.equals(other.object) && this._graph.equals(other.graph);
  }
}
exports.Triple = exports.Quad = Quad;
// ### Escapes the quotes within the given literal
function escapeQuotes(id) {
  return id.replace(escapedLiteral, (_, quoted) => `"${quoted.replace(/"/g, '""')}`);
}

// ### Unescapes the quotes within the given literal
function unescapeQuotes(id) {
  return id.replace(escapedLiteral, (_, quoted) => `"${quoted.replace(/""/g, '"')}`);
}

// ### Creates an IRI
function namedNode(iri) {
  return new NamedNode(iri);
}

// ### Creates a blank node
function blankNode(name) {
  return new BlankNode(name || `n3-${_blankNodeCounter++}`);
}

// ### Creates a literal
function literal(value, languageOrDataType) {
  // Create a language-tagged string
  if (typeof languageOrDataType === 'string') return new Literal(`"${value}"@${languageOrDataType.toLowerCase()}`);

  // Create a language-tagged string with base direction
  if (languageOrDataType !== undefined && !('termType' in languageOrDataType)) {
    return new Literal(`"${value}"@${languageOrDataType.language.toLowerCase()}${languageOrDataType.direction ? `--${languageOrDataType.direction.toLowerCase()}` : ''}`);
  }

  // Automatically determine datatype for booleans and numbers
  let datatype = languageOrDataType ? languageOrDataType.value : '';
  if (datatype === '') {
    // Convert a boolean
    if (typeof value === 'boolean') datatype = xsd.boolean;
    // Convert an integer or double
    else if (typeof value === 'number') {
      if (Number.isFinite(value)) datatype = Number.isInteger(value) ? xsd.integer : xsd.double;else {
        datatype = xsd.double;
        if (!Number.isNaN(value)) value = value > 0 ? 'INF' : '-INF';
      }
    }
  }

  // Create a datatyped literal
  return datatype === '' || datatype === xsd.string ? new Literal(`"${value}"`) : new Literal(`"${value}"^^${datatype}`);
}

// ### Creates a variable
function variable(name) {
  return new Variable(name);
}

// ### Returns the default graph
function defaultGraph() {
  return DEFAULTGRAPH;
}

// ### Creates a quad
function quad(subject, predicate, object, graph) {
  return new Quad(subject, predicate, object, graph);
}
function fromTerm(term) {
  if (term instanceof Term) return term;

  // Term instantiated with another library
  switch (term.termType) {
    case 'NamedNode':
      return namedNode(term.value);
    case 'BlankNode':
      return blankNode(term.value);
    case 'Variable':
      return variable(term.value);
    case 'DefaultGraph':
      return DEFAULTGRAPH;
    case 'Literal':
      return literal(term.value, term.language || term.datatype);
    case 'Quad':
      return fromQuad(term);
    default:
      throw new Error(`Unexpected termType: ${term.termType}`);
  }
}
function fromQuad(inQuad) {
  if (inQuad instanceof Quad) return inQuad;
  if (inQuad.termType !== 'Quad') throw new Error(`Unexpected termType: ${inQuad.termType}`);
  return quad(fromTerm(inQuad.subject), fromTerm(inQuad.predicate), fromTerm(inQuad.object), fromTerm(inQuad.graph));
}