mathjs/lib/expression/node/ArrayNode.js

'use strict';

var string = require('../../utils/string');

function factory (type, config, load, typed) {
  var Node = load(require('./Node'));

  /**
   * @constructor ArrayNode
   * @extends {Node}
   * Holds an 1-dimensional array with nodes
   * @param {Node[]} [nodes]   1 dimensional array with nodes
   */
  function ArrayNode(nodes) {
    if (!(this instanceof ArrayNode)) {
      throw new SyntaxError('Constructor must be called with the new operator');
    }

    this.nodes = nodes || [];

    // validate input
    if (!Array.isArray(this.nodes)
        || !this.nodes.every(function (node) {return node && node.isNode;})) {
      throw new TypeError('Array containing Nodes expected');
    }
  }

  ArrayNode.prototype = new Node();

  ArrayNode.prototype.type = 'ArrayNode';

  ArrayNode.prototype.isArrayNode = true;

  /**
   * Compile the node to javascript code
   * @param {Object} defs     Object which can be used to define functions
   *                          or constants globally available for the compiled
   *                          expression
   * @param {Object} args     Object with local function arguments, the key is
   *                          the name of the argument, and the value is `true`.
   *                          The object may not be mutated, but must be
   *                          extended instead.
   * @private
   */
  ArrayNode.prototype._compile = function (defs, args) {
    var asMatrix = (defs.math.config().matrix !== 'array');

    var nodes = this.nodes.map(function (node) {
      return node._compile(defs, args);
    });

    return (asMatrix ? 'math.matrix([' : '[') +
        nodes.join(',') +
        (asMatrix ? '])' : ']');
  };

  /**
   * Execute a callback for each of the child nodes of this node
   * @param {function(child: Node, path: string, parent: Node)} callback
   */
  ArrayNode.prototype.forEach = function (callback) {
    for (var i = 0; i < this.nodes.length; i++) {
      var node = this.nodes[i];
      callback(node, 'nodes[' + i + ']', this);
    }
  };

  /**
   * Create a new ArrayNode having it's childs be the results of calling
   * the provided callback function for each of the childs of the original node.
   * @param {function(child: Node, path: string, parent: Node): Node} callback
   * @returns {ArrayNode} Returns a transformed copy of the node
   */
  ArrayNode.prototype.map = function (callback) {
    var nodes = [];
    for (var i = 0; i < this.nodes.length; i++) {
      nodes[i] = this._ifNode(callback(this.nodes[i], 'nodes[' + i + ']', this));
    }
    return new ArrayNode(nodes);
  };

  /**
   * Create a clone of this node, a shallow copy
   * @return {ArrayNode}
   */
  ArrayNode.prototype.clone = function() {
    return new ArrayNode(this.nodes.slice(0));
  };

  /**
   * Get string representation
   * @param {Object} options
   * @return {string} str
   * @override
   */
  ArrayNode.prototype._toString = function(options) {
    return string.format(this.nodes);
  };

  /**
   * Get LaTeX representation
   * @param {Object} options
   * @return {string} str
   */
  ArrayNode.prototype._toTex = function(options) {
    var s = '\\begin{bmatrix}';

    this.nodes.forEach(function(node) {
      if (node.nodes) {
        s += node.nodes.map(function(childNode) {
          return childNode.toTex(options);
        }).join('&');
      }
      else {
        s += node.toTex(options);
      }

      // new line
      s += '\\\\';
    });
    s += '\\end{bmatrix}';
    return s;
  };

  return ArrayNode;
}

exports.name = 'ArrayNode';
exports.path = 'expression.node';
exports.factory = factory;