mathjs/lib/expression/node/ArrayNode.js

'use strict';

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

function factory (type, config, load, typed) {
  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(type.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 a node into a JavaScript function.
   * This basically pre-calculates as much as possible and only leaves open
   * calculations which depend on a dynamic scope with variables.
   * @param {Object} math     Math.js namespace with functions and constants. 
   * @param {Object} argNames An object with argument names as key and `true`
   *                          as value. Used in the SymbolNode to optimize
   *                          for arguments from user assigned functions
   *                          (see FunctionAssignmentNode) or special symbols
   *                          like `end` (see IndexNode).
   * @return {function} Returns a function which can be called like:
   *                        evalNode(scope: Object, args: Object, context: *)
   */
  ArrayNode.prototype._compile = function (math, argNames) {
    var evalItems = map(this.items, function (item) {
      return item._compile(math, argNames);
    });

    var asMatrix = (math.config().matrix !== 'Array');
    if (asMatrix) {
      var matrix = math.matrix;
      return function evalArrayNode (scope, args, context) {
        return matrix(map(evalItems, function (evalItem) {
          return evalItem(scope, args, context);
        }));
      };
    }
    else {
      return function evalArrayNode (scope, args, context) {
        return map(evalItems, function (evalItem) {
          return evalItem(scope, args, context);
        });
      };
    }
  }

      /**
   * 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;