mathjs/lib/expression/node/ArrayNode.js

'use strict';

var map = require('../../utils/array').map;
var join = require('../../utils/array').join;

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

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

    this.items = items || [];

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

    // TODO: deprecated since v3, remove some day
    var deprecated = function () {
      throw new Error('Property `ArrayNode.nodes` is deprecated, use `ArrayNode.items` instead');
    };
    Object.defineProperty(this, 'nodes', { get: deprecated, set: deprecated });
  }

  ArrayNode.prototype = new Node();

  ArrayNode.prototype.type = 'ArrayNode';

  ArrayNode.prototype.isArrayNode = true;

  /**
   * Compile the node to javascript code
   * @param {ArrayNode} node  Node to be compiled
   * @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
   */
  function compileArrayNode(node, defs, args) {
    if (!(node instanceof ArrayNode)) {
      throw new TypeError('No valid ArrayNode')
    }

    var asMatrix = (defs.math.config().matrix !== 'Array');

    var items = map(node.items, function (item) {
      return compile(item, defs, args);
    });

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

  // register the compile function
  register(ArrayNode.prototype.type, compileArrayNode);

      /**
   * 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.items.length; i++) {
      var node = this.items[i];
      callback(node, 'items[' + 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 items = [];
    for (var i = 0; i < this.items.length; i++) {
      items[i] = this._ifNode(callback(this.items[i], 'items[' + i + ']', this));
    }
    return new ArrayNode(items);
  };

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

  /**
   * Get string representation
   * @param {Object} options
   * @return {string} str
   * @override
   */
  ArrayNode.prototype._toString = function(options) {
    var items = this.items.map(function (node) {
      return node.toString(options);
    });
    return '[' + items.join(', ') + ']';
  };

  /**
   * Get HTML representation
   * @param {Object} options
   * @return {string} str
   * @override
   */
  ArrayNode.prototype.toHTML = function(options) {
    var items = this.items.map(function (node) {
      return node.toHTML(options);
    });
    return '<span class="math-parenthesis math-square-parenthesis">[</span>' + items.join('<span class="math-separator">,</span>') + '<span class="math-parenthesis math-square-parenthesis">]</span>';
  };

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

    this.items.forEach(function(node) {
      if (node.items) {
        s += node.items.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;