Class Parser

static/katex/katex.mjs:14896–15888

* This file contains the parser used to parse out a TeX expression from the * input. Since TeX isn't context-free, standard parsers don't work particularly * well. * * The strategy of this parser is as such: * * The main functions (the `.parse...` ones) take a position in the current * parse

 * The functions return ParseNodes.
 */
class Parser {
  constructor(input, settings) {
    this.mode = void 0;
    this.gullet = void 0;
    this.settings = void 0;
    this.leftrightDepth = void 0;
    this.nextToken = void 0;
    // Start in math mode
    this.mode = "math"; // Create a new macro expander (gullet) and (indirectly via that) also a
    // new lexer (mouth) for this parser (stomach, in the language of TeX)

    this.gullet = new MacroExpander(input, settings, this.mode); // Store the settings for use in parsing

    this.settings = settings; // Count leftright depth (for \middle errors)

    this.leftrightDepth = 0;
  }
  /**
   * Checks a result to make sure it has the right type, and throws an
   * appropriate error otherwise.
   */


  expect(text, consume) {
    if (consume === void 0) {
      consume = true;
    }

    if (this.nextToken.text !== text) {
      throw new ParseError("Expected '" + text + "', got '" + this.nextToken.text + "'", this.nextToken);
    }

    if (consume) {
      this.consume();
    }
  }
  /**
   * Considers the current look ahead token as consumed,
   * and fetches the one after that as the new look ahead.
   */


  consume() {
    this.nextToken = this.gullet.expandNextToken();
  }
  /**
   * Switches between "text" and "math" modes.
   */


  switchMode(newMode) {
    this.mode = newMode;
    this.gullet.switchMode(newMode);
  }
  /**
   * Main parsing function, which parses an entire input.
   */