mathjs/es/expression/node/SymbolNode.js

import { escape } from '../../utils/string';
import { getSafeProperty } from '../../utils/customs';
import { factory } from '../../utils/factory';
import { toSymbol } from '../../utils/latex';
var name = 'SymbolNode';
var dependencies = ['math', '?Unit', 'Node'];
export var createSymbolNode = /* #__PURE__ */factory(name, dependencies, function (_ref) {
  var math = _ref.math,
      Unit = _ref.Unit,
      Node = _ref.Node;

  /**
   * Check whether some name is a valueless unit like "inch".
   * @param {string} name
   * @return {boolean}
   */
  function isValuelessUnit(name) {
    return Unit ? 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 (argNames[name] === true) {
      // 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 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 = 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;
}, {
  isClass: true,
  isNode: true
});