text: 'use strict';
  
  var latex = require('../../utils/latex');
  
  var escape = require('../../utils/string').escape;
  
  var hasOwnProperty = require('../../utils/object').hasOwnProperty;
  
  var getSafeProperty = require('../../utils/customs').getSafeProperty;
  
  function factory(type, config, load, typed, math) {
    var Node = load(require('./Node'));
    /**
     * Check whether some name is a valueless unit like "inch".
     * @param {string} name
     * @return {boolean}
     */
  
    function isValuelessUnit(name) {
      return type.Unit ? type.Unit.isValuelessUnit(name) : false;
    }
    /**
     * @constructor SymbolNode
     * @extends {Node}
     * A symbol node can hold and resolve a symbol
     * @param {string} name
     * @extends {Node}
     */
  
  
    function SymbolNode(name) {
      if (!(this instanceof SymbolNode)) {
        throw new SyntaxError('Constructor must be called with the new operator');
      } // validate input
  
  
      if (typeof name !== 'string') throw new TypeError('String expected for parameter "name"');
      this.name = name;
    }
  
    SymbolNode.prototype = new Node();
    SymbolNode.prototype.type = 'SymbolNode';
    SymbolNode.prototype.isSymbolNode = 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: *)
     */
  
    SymbolNode.prototype._compile = function (math, argNames) {
      var name = this.name;
  
      if (hasOwnProperty(argNames, name)) {
        // this is a FunctionAssignment argument
        // (like an x when inside the expression of a function assignment `f(x) = ...`)
        return function (scope, args, context) {
          return args[name];
        };
      } else if (name in math) {
        return function (scope, args, context) {
          return name in scope ? getSafeProperty(scope, name) : getSafeProperty(math, name);
        };
      } else {
        var isUnit = isValuelessUnit(name);
        return function (scope, args, context) {
          return name in scope ? getSafeProperty(scope, name) : isUnit ? new type.Unit(null, name) : undef(name);
        };
      }
    };
    /**
     * Execute a callback for each of the child nodes of this node
     * @param {function(child: Node, path: string, parent: Node)} callback
     */
  
  
    SymbolNode.prototype.forEach = function (callback) {} // nothing to do, we don't have childs
  
    /**
     * Create a new SymbolNode 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 {SymbolNode} Returns a clone of the node
     */
    ;
  
    SymbolNode.prototype.map = function (callback) {
      return this.clone();
    };
    /**
     * Throws an error 'Undefined symbol {name}'
     * @param {string} name
     */
  
  
    function undef(name) {
      throw new Error('Undefined symbol ' + name);
    }
    /**
     * Create a clone of this node, a shallow copy
     * @return {SymbolNode}
     */
  
  
    SymbolNode.prototype.clone = function () {
      return new SymbolNode(this.name);
    };
    /**
     * Get string representation
     * @param {Object} options
     * @return {string} str
     * @override
     */
  
  
    SymbolNode.prototype._toString = function (options) {
      return this.name;
    };
    /**
     * Get HTML representation
     * @param {Object} options
     * @return {string} str
     * @override
     */
  
  
    SymbolNode.prototype.toHTML = function (options) {
      var name = escape(this.name);
  
      if (name === 'true' || name === 'false') {
        return '<span class="math-symbol math-boolean">' + name + '</span>';
      } else if (name === 'i') {
        return '<span class="math-symbol math-imaginary-symbol">' + name + '</span>';
      } else if (name === 'Infinity') {
        return '<span class="math-symbol math-infinity-symbol">' + name + '</span>';
      } else if (name === 'NaN') {
        return '<span class="math-symbol math-nan-symbol">' + name + '</span>';
      } else if (name === 'null') {
        return '<span class="math-symbol math-null-symbol">' + name + '</span>';
      } else if (name === 'undefined') {
        return '<span class="math-symbol math-undefined-symbol">' + name + '</span>';
      }
  
      return '<span class="math-symbol">' + name + '</span>';
    };
    /**
     * Get a JSON representation of the node
     * @returns {Object}
     */
  
  
    SymbolNode.prototype.toJSON = function () {
      return {
        mathjs: 'SymbolNode',
        name: this.name
      };
    };
    /**
     * Instantiate a SymbolNode from its JSON representation
     * @param {Object} json  An object structured like
     *                       `{"mathjs": "SymbolNode", name: "x"}`,
     *                       where mathjs is optional
     * @returns {SymbolNode}
     */
  
  
    SymbolNode.fromJSON = function (json) {
      return new SymbolNode(json.name);
    };
    /**
     * Get LaTeX representation
     * @param {Object} options
     * @return {string} str
     * @override
     */
  
  
    SymbolNode.prototype._toTex = function (options) {
      var isUnit = false;
  
      if (typeof math[this.name] === 'undefined' && isValuelessUnit(this.name)) {
        isUnit = true;
      }
  
      var symbol = latex.toSymbol(this.name, isUnit);
  
      if (symbol[0] === '\\') {
        // no space needed if the symbol starts with '\'
        return symbol;
      } // the space prevents symbols from breaking stuff like '\cdot' if it's written right before the symbol
  
  
      return ' ' + symbol;
    };
  
    return SymbolNode;
  }
  
  exports.name = 'SymbolNode';
  exports.path = 'expression.node';
  exports.math = true; // request access to the math namespace as 5th argument of the factory function
  
  exports.factory = factory;