lib/mhchem.js

/* eslint-disable */
/* -*- Mode: Javascript; indent-tabs-mode:nil; js-indent-level: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */

/*************************************************************
 *
 *  KaTeX mhchem.js
 *
 *  This file implements a KaTeX version of mhchem version 3.3.0.
 *  It is adapted from MathJax/extensions/TeX/mhchem.js
 *  It differs from the MathJax version as follows:
 *    1. The interface is changed so that it can be called from KaTeX, not MathJax.
 *    2. \rlap and \llap are replaced with \mathrlap and \mathllap.
 *    3. Four lines of code are edited in order to use \raisebox instead of \raise.
 *    4. The reaction arrow code is simplified. All reaction arrows are rendered
 *       using KaTeX extensible arrows instead of building non-extensible arrows.
 *    5. \tripledash vertical alignment is slightly adjusted.
 *
 *    This code, as other KaTeX code, is released under the MIT license.
 * 
 * /*************************************************************
 *
 *  MathJax/extensions/TeX/mhchem.js
 *
 *  Implements the \ce command for handling chemical formulas
 *  from the mhchem LaTeX package.
 *
 *  ---------------------------------------------------------------------
 *
 *  Copyright (c) 2011-2015 The MathJax Consortium
 *  Copyright (c) 2015-2018 Martin Hensel
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

//
// Coding Style
//   - use '' for identifiers that can by minified/uglified
//   - use "" for strings that need to stay untouched

// version: "3.3.0" for MathJax and KaTeX


// Add \ce, \pu, and \tripledash to the KaTeX macros.

katex.__defineMacro("\\ce", function(context) {
    return chemParse(context.consumeArgs(1)[0], "ce")
  });
  
  katex.__defineMacro("\\pu", function(context) {
    return chemParse(context.consumeArgs(1)[0], "pu");
  });
  
  //  Needed for \bond for the ~ forms
  //  Raise by 2.56mu, not 2mu. We're raising a hyphen-minus, U+002D, not 
  //  a mathematical minus, U+2212. So we need that extra 0.56.
  katex.__defineMacro("\\tripledash", "{\\vphantom{-}\\raisebox{2.56mu}{$\\mkern2mu"
  + "\\tiny\\text{-}\\mkern1mu\\text{-}\\mkern1mu\\text{-}\\mkern2mu$}}");
  
  import katex from "katex";
  
    //
    //  This is the main function for handing the \ce and \pu commands.
    //  It takes the argument to \ce or \pu and returns the corresponding TeX string.
    //
  
    var chemParse = function (tokens, stateMachine) {
      // Recreate the argument string from KaTeX's array of tokens.
      var str = "";
      var expectedLoc = tokens.length && tokens[tokens.length - 1].loc.start
      for (var i = tokens.length - 1; i >= 0; i--) {
        if(tokens[i].loc.start > expectedLoc) {
          // context.consumeArgs has eaten a space.
          str += " ";
          expectedLoc = tokens[i].loc.start;
        }
        str += tokens[i].text;
        expectedLoc += tokens[i].text.length;
      }
      var tex = texify.go(mhchemParser.go(str, stateMachine));
      return tex;
    };
  
    //
    // Core parser for mhchem syntax  (recursive)
    //
    /** @type {MhchemParser} */
    var mhchemParser = {
      //
      // Parses mchem \ce syntax
      //
      // Call like
      //   go("H2O");
      //
      go: function (input, stateMachine) {
        if (!input) { return []; }
        if (stateMachine === undefined) { stateMachine = 'ce'; }
        var state = '0';
  
        //
        // String buffers for parsing:
        //
        // buffer.a == amount
        // buffer.o == element
        // buffer.b == left-side superscript
        // buffer.p == left-side subscript
        // buffer.q == right-side subscript
        // buffer.d == right-side superscript
        //
        // buffer.r == arrow
        // buffer.rdt == arrow, script above, type
        // buffer.rd == arrow, script above, content
        // buffer.rqt == arrow, script below, type
        // buffer.rq == arrow, script below, content
        //
        // buffer.text_
        // buffer.rm
        // etc.
        //
        // buffer.parenthesisLevel == int, starting at 0
        // buffer.sb == bool, space before
        // buffer.beginsWithBond == bool
        //
        // These letters are also used as state names.
        //
        // Other states:
        // 0 == begin of main part (arrow/operator unlikely)
        // 1 == next entity
        // 2 == next entity (arrow/operator unlikely)
        // 3 == next atom
        // c == macro
        //
        /** @type {Buffer} */
        var buffer = {};
        buffer['parenthesisLevel'] = 0;
  
        input = input.replace(/\n/g, " ");
        input = input.replace(/[\u2212\u2013\u2014\u2010]/g, "-");
        input = input.replace(/[\u2026]/g, "...");
  
        //
        // Looks through mhchemParser.transitions, to execute a matching action
        // (recursive)
        //
        var lastInput;
        var watchdog = 10;
        /** @type {ParserOutput[]} */
        var output = [];
        while (true) {
          if (lastInput !== input) {
            watchdog = 10;
            lastInput = input;
          } else {
            watchdog--;
          }
          //
          // Find actions in transition table
          //
          var machine = mhchemParser.stateMachines[stateMachine];
          var t = machine.transitions[state] || machine.transitions['*'];
          iterateTransitions:
          for (var i=0; i<t.length; i++) {
            var matches = mhchemParser.patterns.match_(t[i].pattern, input);
            if (matches) {
              //
              // Execute actions
              //
              var task = t[i].task;
              for (var iA=0; iA<task.action_.length; iA++) {
                var o;
                //
                // Find and execute action
                //
                if (machine.actions[task.action_[iA].type_]) {
                  o = machine.actions[task.action_[iA].type_](buffer, matches.match_, task.action_[iA].option);
                } else if (mhchemParser.actions[task.action_[iA].type_]) {
                  o = mhchemParser.actions[task.action_[iA].type_](buffer, matches.match_, task.action_[iA].option);
                } else {
                  throw ["MhchemBugA", "mhchem bug A. Please report. (" + task.action_[iA].type_ + ")"];  // Trying to use non-existing action
                }
                //
                // Add output
                //
                mhchemParser.concatArray(output, o);
              }
              //
              // Set next state,
              // Shorten input,
              // Continue with next character
              //   (= apply only one transition per position)
              //
              state = task.nextState || state;
              if (input.length > 0) {
                if (!task.revisit) {
                  input = matches.remainder;
                }
                if (!task.toContinue) {
                  break iterateTransitions;
                }
              } else {
                return output;
              }
            }
          }
          //
          // Prevent infinite loop
          //
          if (watchdog <= 0) {
            throw ["MhchemBugU", "mhchem bug U. Please report."];  // Unexpected character
          }
        }
      },
      concatArray: function (a, b) {
        if (b) {
          if (Array.isArray(b)) {
            for (var iB=0; iB<b.length; iB++) {
              a.push(b[iB]);
            }
          } else {
            a.push(b);
          }
        }
      },
  
      patterns: {
        //
        // Matching patterns
        // either regexps or function that return null or {match_:"a", remainder:"bc"}
        //
        patterns: {
          // property names must not look like integers ("2") for correct property traversal order, later on
          'empty': /^$/,
          'else': /^./,
          'else2': /^./,
          'space': /^\s/,
          'space A': /^\s(?=[A-Z\\$])/,
          'space$': /^\s$/,
          'a-z': /^[a-z]/,
          'x': /^x/,
          'x$': /^x$/,
          'i$': /^i$/,
          'letters': /^(?:[a-zA-Z\u03B1-\u03C9\u0391-\u03A9?@]|(?:\\(?:alpha|beta|gamma|delta|epsilon|zeta|eta|theta|iota|kappa|lambda|mu|nu|xi|omicron|pi|rho|sigma|tau|upsilon|phi|chi|psi|omega|Gamma|Delta|Theta|Lambda|Xi|Pi|Sigma|Upsilon|Phi|Psi|Omega)(?:\s+|\{\}|(?![a-zA-Z]))))+/,
          '\\greek': /^\\(?:alpha|beta|gamma|delta|epsilon|zeta|eta|theta|iota|kappa|lambda|mu|nu|xi|omicron|pi|rho|sigma|tau|upsilon|phi|chi|psi|omega|Gamma|Delta|Theta|Lambda|Xi|Pi|Sigma|Upsilon|Phi|Psi|Omega)(?:\s+|\{\}|(?![a-zA-Z]))/,
          'one lowercase latin letter $': /^(?:([a-z])(?:$|[^a-zA-Z]))$/,
          '$one lowercase latin letter$ $': /^\$(?:([a-z])(?:$|[^a-zA-Z]))\$$/,
          'one lowercase greek letter $': /^(?:\$?[\u03B1-\u03C9]\$?|\$?\\(?:alpha|beta|gamma|delta|epsilon|zeta|eta|theta|iota|kappa|lambda|mu|nu|xi|omicron|pi|rho|sigma|tau|upsilon|phi|chi|psi|omega)\s*\$?)(?:\s+|\{\}|(?![a-zA-Z]))$/,
          'digits': /^[0-9]+/,
          '-9.,9': /^[+\-]?(?:[0-9]+(?:[,.][0-9]+)?|[0-9]*(?:\.[0-9]+))/,
          '-9.,9 no missing 0': /^[+\-]?[0-9]+(?:[.,][0-9]+)?/,
          '(-)(9.,9)(e)(99)': function (input) {
            var m = input.match(/^(\+\-|\+\/\-|\+|\-|\\pm\s?)?([0-9]+(?:[,.][0-9]+)?|[0-9]*(?:\.[0-9]+))?(\((?:[0-9]+(?:[,.][0-9]+)?|[0-9]*(?:\.[0-9]+))\))?(?:([eE]|\s*(\*|x|\\times|\u00D7)\s*10\^)([+\-]?[0-9]+|\{[+\-]?[0-9]+\}))?/);
            if (m && m[0]) {
              return { match_: m.splice(1), remainder: input.substr(m[0].length) };
            }
            return null;
          },
          '(-)(9)^(-9)': function (input) {
            var m = input.match(/^(\+\-|\+\/\-|\+|\-|\\pm\s?)?([0-9]+(?:[,.][0-9]+)?|[0-9]*(?:\.[0-9]+)?)\^([+\-]?[0-9]+|\{[+\-]?[0-9]+\})/);
            if (m && m[0]) {
              return { match_: m.splice(1), remainder: input.substr(m[0].length) };
            }
            return null;
          },
          'state of aggregation $': function (input) {  // ... or crystal system
            var a = mhchemParser.patterns.findObserveGroups(input, "", /^\([a-z]{1,3}(?=[\),])/, ")", "");  // (aq), (aq,$\infty$), (aq, sat)
            if (a  &&  a.remainder.match(/^($|[\s,;\)\]\}])/)) { return a; }  //  AND end of 'phrase'
            var m = input.match(/^(?:\((?:\\ca\s?)?\$[amothc]\$\))/);  // OR crystal system ($o$) (\ca$c$)
            if (m) {
              return { match_: m[0], remainder: input.substr(m[0].length) };
            }
            return null;
          },
          '_{(state of aggregation)}$': /^_\{(\([a-z]{1,3}\))\}/,
          '{[(': /^(?:\\\{|\[|\()/,
          ')]}': /^(?:\)|\]|\\\})/,
          ', ': /^[,;]\s*/,
          ',': /^[,;]/,
          '.': /^[.]/,
          '. ': /^([.\u22C5\u00B7\u2022])\s*/,
          '...': /^\.\.\.(?=$|[^.])/,
          '* ': /^([*])\s*/,
          '^{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "^{", "", "", "}"); },
          '^($...$)': function (input) { return mhchemParser.patterns.findObserveGroups(input, "^", "$", "$", ""); },
          '^a': /^\^([0-9]+|[^\\_])/,
          '^\\x{}{}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "^", /^\\[a-zA-Z]+\{/, "}", "", "", "{", "}", "", true); },
          '^\\x{}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "^", /^\\[a-zA-Z]+\{/, "}", ""); },
          '^\\x': /^\^(\\[a-zA-Z]+)\s*/,
          '^(-1)': /^\^(-?\d+)/,
          '\'': /^'/,
          '_{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "_{", "", "", "}"); },
          '_($...$)': function (input) { return mhchemParser.patterns.findObserveGroups(input, "_", "$", "$", ""); },
          '_9': /^_([+\-]?[0-9]+|[^\\])/,
          '_\\x{}{}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "_", /^\\[a-zA-Z]+\{/, "}", "", "", "{", "}", "", true); },
          '_\\x{}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "_", /^\\[a-zA-Z]+\{/, "}", ""); },
          '_\\x': /^_(\\[a-zA-Z]+)\s*/,
          '^_': /^(?:\^(?=_)|\_(?=\^)|[\^_]$)/,
          '{}': /^\{\}/,
          '{...}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "", "{", "}", ""); },
          '{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "{", "", "", "}"); },
          '$...$': function (input) { return mhchemParser.patterns.findObserveGroups(input, "", "$", "$", ""); },
          '${(...)}$': function (input) { return mhchemParser.patterns.findObserveGroups(input, "${", "", "", "}$"); },
          '$(...)$': function (input) { return mhchemParser.patterns.findObserveGroups(input, "$", "", "", "$"); },
          '=<>': /^[=<>]/,
          '#': /^[#\u2261]/,
          '+': /^\+/,
          '-$': /^-(?=[\s_},;\]/]|$|\([a-z]+\))/,  // -space -, -; -] -/ -$ -state-of-aggregation
          '-9': /^-(?=[0-9])/,
          '- orbital overlap': /^-(?=(?:[spd]|sp)(?:$|[\s,;\)\]\}]))/,
          '-': /^-/,
          'pm-operator': /^(?:\\pm|\$\\pm\$|\+-|\+\/-)/,
          'operator': /^(?:\+|(?:[\-=<>]|<<|>>|\\approx|\$\\approx\$)(?=\s|$|-?[0-9]))/,
          'arrowUpDown': /^(?:v|\(v\)|\^|\(\^\))(?=$|[\s,;\)\]\}])/,
          '\\bond{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\bond{", "", "", "}"); },
          '->': /^(?:<->|<-->|->|<-|<=>>|<<=>|<=>|[\u2192\u27F6\u21CC])/,
          'CMT': /^[CMT](?=\[)/,
          '[(...)]': function (input) { return mhchemParser.patterns.findObserveGroups(input, "[", "", "", "]"); },
          '1st-level escape': /^(&|\\\\|\\hline)\s*/,
          '\\,': /^(?:\\[,\ ;:])/,  // \\x - but output no space before
          '\\x{}{}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "", /^\\[a-zA-Z]+\{/, "}", "", "", "{", "}", "", true); },
          '\\x{}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "", /^\\[a-zA-Z]+\{/, "}", ""); },
          '\\ca': /^\\ca(?:\s+|(?![a-zA-Z]))/,
          '\\x': /^(?:\\[a-zA-Z]+\s*|\\[_&{}%])/,
          'orbital': /^(?:[0-9]{1,2}[spdfgh]|[0-9]{0,2}sp)(?=$|[^a-zA-Z])/,  // only those with numbers in front, because the others will be formatted correctly anyway
          'others': /^[\/~|]/,
          '\\frac{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\frac{", "", "", "}", "{", "", "", "}"); },
          '\\overset{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\overset{", "", "", "}", "{", "", "", "}"); },
          '\\underset{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\underset{", "", "", "}", "{", "", "", "}"); },
          '\\underbrace{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\underbrace{", "", "", "}_", "{", "", "", "}"); },
          '\\color{(...)}0': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\color{", "", "", "}"); },
          '\\color{(...)}{(...)}1': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\color{", "", "", "}", "{", "", "", "}"); },
          '\\color(...){(...)}2': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\color", "\\", "", /^(?=\{)/, "{", "", "", "}"); },
          '\\ce{(...)}': function (input) { return mhchemParser.patterns.findObserveGroups(input, "\\ce{", "", "", "}"); },
          'oxidation$': /^(?:[+-][IVX]+|\\pm\s*0|\$\\pm\$\s*0)$/,
          'd-oxidation$': /^(?:[+-]?\s?[IVX]+|\\pm\s*0|\$\\pm\$\s*0)$/,  // 0 could be oxidation or charge
          'roman numeral': /^[IVX]+/,
          '1/2$': /^[+\-]?(?:[0-9]+|\$[a-z]\$|[a-z])\/[0-9]+(?:\$[a-z]\$|[a-z])?$/,
          'amount': function (input) {
            var match;
            // e.g. 2, 0.5, 1/2, -2, n/2, +;  $a$ could be added later in parsing
            match = input.match(/^(?:(?:(?:\([+\-]?[0-9]+\/[0-9]+\)|[+\-]?(?:[0-9]+|\$[a-z]\$|[a-z])\/[0-9]+|[+\-]?[0-9]+[.,][0-9]+|[+\-]?\.[0-9]+|[+\-]?[0-9]+)(?:[a-z](?=\s*[A-Z]))?)|[+\-]?[a-z](?=\s*[A-Z])|\+(?!\s))/);
            if (match) {
              return { match_: match[0], remainder: input.substr(match[0].length) };
            }
            var a = mhchemParser.patterns.findObserveGroups(input, "", "$", "$", "");
            if (a) {  // e.g. $2n-1$, $-$
              match = a.match_.match(/^\$(?:\(?[+\-]?(?:[0-9]*[a-z]?[+\-])?[0-9]*[a-z](?:[+\-][0-9]*[a-z]?)?\)?|\+|-)\$$/);
              if (match) {
                return { match_: match[0], remainder: input.substr(match[0].length) };
              }
            }
            return null;
          },
          'amount2': function (input) { return this['amount'](input); },
          '(KV letters),': /^(?:[A-Z][a-z]{0,2}|i)(?=,)/,
          'formula$': function (input) {
            if (input.match(/^\([a-z]+\)$/)) { return null; }  // state of aggregation = no formula
            var match = input.match(/^(?:[a-z]|(?:[0-9\ \+\-\,\.\(\)]+[a-z])+[0-9\ \+\-\,\.\(\)]*|(?:[a-z][0-9\ \+\-\,\.\(\)]+)+[a-z]?)$/);
            if (match) {
              return { match_: match[0], remainder: input.substr(match[0].length) };
            }
            return null;
          },
          'uprightEntities': /^(?:pH|pOH|pC|pK|iPr|iBu)(?=$|[^a-zA-Z])/,
          '/': /^\s*(\/)\s*/,
          '//': /^\s*(\/\/)\s*/,
          '*': /^\s*[*.]\s*/
        },
        findObserveGroups: function (input, begExcl, begIncl, endIncl, endExcl, beg2Excl, beg2Incl, end2Incl, end2Excl, combine) {
          /** @type {{(input: string, pattern: string | RegExp): string | string[] | null;}} */
          var _match = function (input, pattern) {
            if (typeof pattern === "string") {
              if (input.indexOf(pattern) !== 0) { return null; }
              return pattern;
            } else {
              var match = input.match(pattern);
              if (!match) { return null; }
              return match[0];
            }
          };
          /** @type {{(input: string, i: number, endChars: string | RegExp): {endMatchBegin: number, endMatchEnd: number} | null;}} */
          var _findObserveGroups = function (input, i, endChars) {
            var braces = 0;
            while (i < input.length) {
              var a = input.charAt(i);
              var match = _match(input.substr(i), endChars);
              if (match !== null  &&  braces === 0) {
                return { endMatchBegin: i, endMatchEnd: i + match.length };
              } else if (a === "{") {
                braces++;
              } else if (a === "}") {
                if (braces === 0) {
                  throw ["ExtraCloseMissingOpen", "Extra close brace or missing open brace"];
                } else {
                  braces--;
                }
              }
              i++;
            }
            if (braces > 0) {
              return null;
            }
            return null;
          };
          var match = _match(input, begExcl);
          if (match === null) { return null; }
          input = input.substr(match.length);
          match = _match(input, begIncl);
          if (match === null) { return null; }
          var e = _findObserveGroups(input, match.length, endIncl || endExcl);
          if (e === null) { return null; }
          var match1 = input.substring(0, (endIncl ? e.endMatchEnd : e.endMatchBegin));
          if (!(beg2Excl || beg2Incl)) {
            return {
              match_: match1,
              remainder: input.substr(e.endMatchEnd)
            };
          } else {
            var group2 = this.findObserveGroups(input.substr(e.endMatchEnd), beg2Excl, beg2Incl, end2Incl, end2Excl);
            if (group2 === null) { return null; }
            /** @type {string[]} */
            var matchRet = [match1, group2.match_];
            return {
              match_: (combine ? matchRet.join("") : matchRet),
              remainder: group2.remainder
            };
          }
        },
  
        //
        // Matching function
        // e.g. match("a", input) will look for the regexp called "a" and see if it matches
        // returns null or {match_:"a", remainder:"bc"}
        //
        match_: function (m, input) {
          var pattern = mhchemParser.patterns.patterns[m];
          if (pattern === undefined) {
            throw ["MhchemBugP", "mhchem bug P. Please report. (" + m + ")"];  // Trying to use non-existing pattern
          } else if (typeof pattern === "function") {
            return mhchemParser.patterns.patterns[m](input);  // cannot use cached var pattern here, because some pattern functions need this===mhchemParser
          } else {  // RegExp
            var match = input.match(pattern);
            if (match) {
              var mm;
              if (match[2]) {
                mm = [ match[1], match[2] ];
              } else if (match[1]) {
                mm = match[1];
              } else {
                mm = match[0];
              }
              return { match_: mm, remainder: input.substr(match[0].length) };
            }
            return null;
          }
        }
      },
  
      //
      // Generic state machine actions
      //
      actions: {
        'a=': function (buffer, m) { buffer.a = (buffer.a || "") + m; },
        'b=': function (buffer, m) { buffer.b = (buffer.b || "") + m; },
        'p=': function (buffer, m) { buffer.p = (buffer.p || "") + m; },
        'o=': function (buffer, m) { buffer.o = (buffer.o || "") + m; },
        'q=': function (buffer, m) { buffer.q = (buffer.q || "") + m; },
        'd=': function (buffer, m) { buffer.d = (buffer.d || "") + m; },
        'rm=': function (buffer, m) { buffer.rm = (buffer.rm || "") + m; },
        'text=': function (buffer, m) { buffer.text_ = (buffer.text_ || "") + m; },
        'insert': function (buffer, m, a) { return { type_: a }; },
        'insert+p1': function (buffer, m, a) { return { type_: a, p1: m }; },
        'insert+p1+p2': function (buffer, m, a) { return { type_: a, p1: m[0], p2: m[1] }; },
        'copy': function (buffer, m) { return m; },
        'rm': function (buffer, m) { return { type_: 'rm', p1: m || ""}; },
        'text': function (buffer, m) { return mhchemParser.go(m, 'text'); },
        '{text}': function (buffer, m) {
          var ret = [ "{" ];
          mhchemParser.concatArray(ret, mhchemParser.go(m, 'text'));
          ret.push("}");
          return ret;
        },
        'tex-math': function (buffer, m) { return mhchemParser.go(m, 'tex-math'); },
        'tex-math tight': function (buffer, m) { return mhchemParser.go(m, 'tex-math tight'); },
        'bond': function (buffer, m, k) { return { type_: 'bond', kind_: k || m }; },
        'color0-output': function (buffer, m) { return { type_: 'color0', color: m[0] }; },
        'ce': function (buffer, m) { return mhchemParser.go(m); },
        '1/2': function (buffer, m) {
          /** @type {ParserOutput[]} */
          var ret = [];
          if (m.match(/^[+\-]/)) {
            ret.push(m.substr(0, 1));
            m = m.substr(1);
          }
          var n = m.match(/^([0-9]+|\$[a-z]\$|[a-z])\/([0-9]+)(\$[a-z]\$|[a-z])?$/);
          n[1] = n[1].replace(/\$/g, "");
          ret.push({ type_: 'frac', p1: n[1], p2: n[2] });
          if (n[3]) {
            n[3] = n[3].replace(/\$/g, "");
            ret.push({ type_: 'tex-math', p1: n[3] });
          }
          return ret;
        },
        '9,9': function (buffer, m) { return mhchemParser.go(m, '9,9'); }
      },
      //
      // createTransitions
      // convert  { 'letter': { 'state': { action_: 'output' } } }  to  { 'state' => [ { pattern: 'letter', task: { action_: [{type_: 'output'}] } } ] }
      // with expansion of 'a|b' to 'a' and 'b' (at 2 places)
      //
      createTransitions: function (o) {
        var pattern, state;
        /** @type {string[]} */
        var stateArray;
        var i;
        //
        // 1. Collect all states
        //
        /** @type {Transitions} */
        var transitions = {};
        for (pattern in o) {
          for (state in o[pattern]) {
            stateArray = state.split("|");
            o[pattern][state].stateArray = stateArray;
            for (i=0; i<stateArray.length; i++) {
              transitions[stateArray[i]] = [];
            }
          }
        }
        //
        // 2. Fill states
        //
        for (pattern in o) {
          for (state in o[pattern]) {
            stateArray = o[pattern][state].stateArray || [];
            for (i=0; i<stateArray.length; i++) {
              //
              // 2a. Normalize actions into array:  'text=' ==> [{type_:'text='}]
              // (Note to myself: Resolving the function here would be problematic. It would need .bind (for *this*) and currying (for *option*).)
              //
              /** @type {any} */
              var p = o[pattern][state];
              if (p.action_) {
                p.action_ = [].concat(p.action_);
                for (var k=0; k<p.action_.length; k++) {
                  if (typeof p.action_[k] === "string") {
                    p.action_[k] = { type_: p.action_[k] };
                  }
                }
              } else {
                p.action_ = [];
              }
              //
              // 2.b Multi-insert
              //
              var patternArray = pattern.split("|");
              for (var j=0; j<patternArray.length; j++) {
                if (stateArray[i] === '*') {  // insert into all
                  for (var t in transitions) {
                    transitions[t].push({ pattern: patternArray[j], task: p });
                  }
                } else {
                  transitions[stateArray[i]].push({ pattern: patternArray[j], task: p });
                }
              }
            }
          }
        }
        return transitions;
      },
      stateMachines: {}
    };
  
    //
    // Definition of state machines
    //
    mhchemParser.stateMachines = {
      //
      // \ce state machines
      //
      //#region ce
      'ce': {  // main parser
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': { action_: 'output' } },
          'else':  {
            '0|1|2': { action_: 'beginsWithBond=false', revisit: true, toContinue: true } },
          'oxidation$': {
            '0': { action_: 'oxidation-output' } },
          'CMT': {
            'r': { action_: 'rdt=', nextState: 'rt' },
            'rd': { action_: 'rqt=', nextState: 'rdt' } },
          'arrowUpDown': {
            '0|1|2|as': { action_: [ 'sb=false', 'output', 'operator' ], nextState: '1' } },
          'uprightEntities': {
            '0|1|2': { action_: [ 'o=', 'output' ], nextState: '1' } },
          'orbital': {
            '0|1|2|3': { action_: 'o=', nextState: 'o' } },
          '->': {
            '0|1|2|3': { action_: 'r=', nextState: 'r' },
            'a|as': { action_: [ 'output', 'r=' ], nextState: 'r' },
            '*': { action_: [ 'output', 'r=' ], nextState: 'r' } },
          '+': {
            'o': { action_: 'd= kv',  nextState: 'd' },
            'd|D': { action_: 'd=', nextState: 'd' },
            'q': { action_: 'd=',  nextState: 'qd' },
            'qd|qD': { action_: 'd=', nextState: 'qd' },
            'dq': { action_: [ 'output', 'd=' ], nextState: 'd' },
            '3': { action_: [ 'sb=false', 'output', 'operator' ], nextState: '0' } },
          'amount': {
            '0|2': { action_: 'a=', nextState: 'a' } },
          'pm-operator': {
            '0|1|2|a|as': { action_: [ 'sb=false', 'output', { type_: 'operator', option: '\\pm' } ], nextState: '0' } },
          'operator': {
            '0|1|2|a|as': { action_: [ 'sb=false', 'output', 'operator' ], nextState: '0' } },
          '-$': {
            'o|q': { action_: [ 'charge or bond', 'output' ],  nextState: 'qd' },
            'd': { action_: 'd=', nextState: 'd' },
            'D': { action_: [ 'output', { type_: 'bond', option: "-" } ], nextState: '3' },
            'q': { action_: 'd=',  nextState: 'qd' },
            'qd': { action_: 'd=', nextState: 'qd' },
            'qD|dq': { action_: [ 'output', { type_: 'bond', option: "-" } ], nextState: '3' } },
          '-9': {
            '3|o': { action_: [ 'output', { type_: 'insert', option: 'hyphen' } ], nextState: '3' } },
          '- orbital overlap': {
            'o': { action_: [ 'output', { type_: 'insert', option: 'hyphen' } ], nextState: '2' },
            'd': { action_: [ 'output', { type_: 'insert', option: 'hyphen' } ], nextState: '2' } },
          '-': {
            '0|1|2': { action_: [ { type_: 'output', option: 1 }, 'beginsWithBond=true', { type_: 'bond', option: "-" } ], nextState: '3' },
            '3': { action_: { type_: 'bond', option: "-" } },
            'a': { action_: [ 'output', { type_: 'insert', option: 'hyphen' } ], nextState: '2' },
            'as': { action_: [ { type_: 'output', option: 2 }, { type_: 'bond', option: "-" } ], nextState: '3' },
            'b': { action_: 'b=' },
            'o': { action_: { type_: '- after o/d', option: false }, nextState: '2' },
            'q': { action_: { type_: '- after o/d', option: false }, nextState: '2' },
            'd|qd|dq': { action_: { type_: '- after o/d', option: true }, nextState: '2' },
            'D|qD|p': { action_: [ 'output', { type_: 'bond', option: "-" } ], nextState: '3' } },
          'amount2': {
            '1|3': { action_: 'a=', nextState: 'a' } },
          'letters': {
            '0|1|2|3|a|as|b|p|bp|o': { action_: 'o=', nextState: 'o' },
            'q|dq': { action_: ['output', 'o='], nextState: 'o' },
            'd|D|qd|qD': { action_: 'o after d', nextState: 'o' } },
          'digits': {
            'o': { action_: 'q=', nextState: 'q' },
            'd|D': { action_: 'q=', nextState: 'dq' },
            'q': { action_: [ 'output', 'o=' ], nextState: 'o' },
            'a': { action_: 'o=', nextState: 'o' } },
          'space A': {
            'b|p|bp': {} },
          'space': {
            'a': { nextState: 'as' },
            '0': { action_: 'sb=false' },
            '1|2': { action_: 'sb=true' },
            'r|rt|rd|rdt|rdq': { action_: 'output', nextState: '0' },
            '*': { action_: [ 'output', 'sb=true' ], nextState: '1'} },
          '1st-level escape': {
            '1|2': { action_: [ 'output', { type_: 'insert+p1', option: '1st-level escape' } ] },
            '*': { action_: [ 'output', { type_: 'insert+p1', option: '1st-level escape' } ], nextState: '0' } },
          '[(...)]': {
            'r|rt': { action_: 'rd=', nextState: 'rd' },
            'rd|rdt': { action_: 'rq=', nextState: 'rdq' } },
          '...': {
            'o|d|D|dq|qd|qD': { action_: [ 'output', { type_: 'bond', option: "..." } ], nextState: '3' },
            '*': { action_: [ { type_: 'output', option: 1 }, { type_: 'insert', option: 'ellipsis' } ], nextState: '1' } },
          '. |* ': {
            '*': { action_: [ 'output', { type_: 'insert', option: 'addition compound' } ], nextState: '1' } },
          'state of aggregation $': {
            '*': { action_: [ 'output', 'state of aggregation' ], nextState: '1' } },
          '{[(': {
            'a|as|o': { action_: [ 'o=', 'output', 'parenthesisLevel++' ], nextState: '2' },
            '0|1|2|3': { action_: [ 'o=', 'output', 'parenthesisLevel++' ], nextState: '2' },
            '*': { action_: [ 'output', 'o=', 'output', 'parenthesisLevel++' ], nextState: '2' } },
          ')]}': {
            '0|1|2|3|b|p|bp|o': { action_: [ 'o=', 'parenthesisLevel--' ], nextState: 'o' },
            'a|as|d|D|q|qd|qD|dq': { action_: [ 'output', 'o=', 'parenthesisLevel--' ], nextState: 'o' } },
          ', ': {
            '*': { action_: [ 'output', 'comma' ], nextState: '0' } },
          '^_': {  // ^ and _ without a sensible argument
            '*': { } },
          '^{(...)}|^($...$)': {
            '0|1|2|as': { action_: 'b=', nextState: 'b' },
            'p': { action_: 'b=', nextState: 'bp' },
            '3|o': { action_: 'd= kv', nextState: 'D' },
            'q': { action_: 'd=', nextState: 'qD' },
            'd|D|qd|qD|dq': { action_: [ 'output', 'd=' ], nextState: 'D' } },
          '^a|^\\x{}{}|^\\x{}|^\\x|\'': {
            '0|1|2|as': { action_: 'b=', nextState: 'b' },
            'p': { action_: 'b=', nextState: 'bp' },
            '3|o': { action_: 'd= kv', nextState: 'd' },
            'q': { action_: 'd=', nextState: 'qd' },
            'd|qd|D|qD': { action_: 'd=' },
            'dq': { action_: [ 'output', 'd=' ], nextState: 'd' } },
          '_{(state of aggregation)}$': {
            'd|D|q|qd|qD|dq': { action_: [ 'output', 'q=' ], nextState: 'q' } },
          '_{(...)}|_($...$)|_9|_\\x{}{}|_\\x{}|_\\x': {
            '0|1|2|as': { action_: 'p=', nextState: 'p' },
            'b': { action_: 'p=', nextState: 'bp' },
            '3|o': { action_: 'q=', nextState: 'q' },
            'd|D': { action_: 'q=', nextState: 'dq' },
            'q|qd|qD|dq': { action_: [ 'output', 'q=' ], nextState: 'q' } },
          '=<>': {
            '0|1|2|3|a|as|o|q|d|D|qd|qD|dq': { action_: [ { type_: 'output', option: 2 }, 'bond' ], nextState: '3' } },
          '#': {
            '0|1|2|3|a|as|o': { action_: [ { type_: 'output', option: 2 }, { type_: 'bond', option: "#" } ], nextState: '3' } },
          '{}': {
            '*': { action_: { type_: 'output', option: 1 },  nextState: '1' } },
          '{...}': {
            '0|1|2|3|a|as|b|p|bp': { action_: 'o=', nextState: 'o' },
            'o|d|D|q|qd|qD|dq': { action_: [ 'output', 'o=' ], nextState: 'o' } },
          '$...$': {
            'a': { action_: 'a=' },  // 2$n$
            '0|1|2|3|as|b|p|bp|o': { action_: 'o=', nextState: 'o' },  // not 'amount'
            'as|o': { action_: 'o=' },
            'q|d|D|qd|qD|dq': { action_: [ 'output', 'o=' ], nextState: 'o' } },
          '\\bond{(...)}': {
            '*': { action_: [ { type_: 'output', option: 2 }, 'bond' ], nextState: "3" } },
          '\\frac{(...)}': {
            '*': { action_: [ { type_: 'output', option: 1 }, 'frac-output' ], nextState: '3' } },
          '\\overset{(...)}': {
            '*': { action_: [ { type_: 'output', option: 2 }, 'overset-output' ], nextState: '3' } },
          '\\underset{(...)}': {
            '*': { action_: [ { type_: 'output', option: 2 }, 'underset-output' ], nextState: '3' } },
          '\\underbrace{(...)}': {
            '*': { action_: [ { type_: 'output', option: 2 }, 'underbrace-output' ], nextState: '3' } },
          '\\color{(...)}{(...)}1|\\color(...){(...)}2': {
            '*': { action_: [ { type_: 'output', option: 2 }, 'color-output' ], nextState: '3' } },
          '\\color{(...)}0': {
            '*': { action_: [ { type_: 'output', option: 2 }, 'color0-output' ] } },
          '\\ce{(...)}': {
            '*': { action_: [ { type_: 'output', option: 2 }, 'ce' ], nextState: '3' } },
          '\\,': {
            '*': { action_: [ { type_: 'output', option: 1 }, 'copy' ], nextState: '1' } },
          '\\x{}{}|\\x{}|\\x': {
            '0|1|2|3|a|as|b|p|bp|o|c0': { action_: [ 'o=', 'output' ], nextState: '3' },
            '*': { action_: ['output', 'o=', 'output' ], nextState: '3' } },
          'others': {
            '*': { action_: [ { type_: 'output', option: 1 }, 'copy' ], nextState: '3' } },
          'else2': {
            'a': { action_: 'a to o', nextState: 'o', revisit: true },
            'as': { action_: [ 'output', 'sb=true' ], nextState: '1', revisit: true },
            'r|rt|rd|rdt|rdq': { action_: [ 'output' ], nextState: '0', revisit: true },
            '*': { action_: [ 'output', 'copy' ], nextState: '3' } }
        }),
        actions: {
          'o after d': function (buffer, m) {
            var ret;
            if ((buffer.d || "").match(/^[0-9]+$/)) {
              var tmp = buffer.d;
              buffer.d = undefined;
              ret = this['output'](buffer);
              buffer.b = tmp;
            } else {
              ret = this['output'](buffer);
            }
            mhchemParser.actions['o='](buffer, m);
            return ret;
          },
          'd= kv': function (buffer, m) {
            buffer.d = m;
            buffer.dType = 'kv';
          },
          'charge or bond': function (buffer, m) {
            if (buffer['beginsWithBond']) {
              /** @type {ParserOutput[]} */
              var ret = [];
              mhchemParser.concatArray(ret, this['output'](buffer));
              mhchemParser.concatArray(ret, mhchemParser.actions['bond'](buffer, m, "-"));
              return ret;
            } else {
              buffer.d = m;
            }
          },
          '- after o/d': function (buffer, m, isAfterD) {
            var c1 = mhchemParser.patterns.match_('orbital', buffer.o || "");
            var c2 = mhchemParser.patterns.match_('one lowercase greek letter $', buffer.o || "");
            var c3 = mhchemParser.patterns.match_('one lowercase latin letter $', buffer.o || "");
            var c4 = mhchemParser.patterns.match_('$one lowercase latin letter$ $', buffer.o || "");
            var hyphenFollows =  m==="-" && ( c1 && c1.remainder===""  ||  c2  ||  c3  ||  c4 );
            if (hyphenFollows && !buffer.a && !buffer.b && !buffer.p && !buffer.d && !buffer.q && !c1 && c3) {
              buffer.o = '$' + buffer.o + '$';
            }
            /** @type {ParserOutput[]} */
            var ret = [];
            if (hyphenFollows) {
              mhchemParser.concatArray(ret, this['output'](buffer));
              ret.push({ type_: 'hyphen' });
            } else {
              c1 = mhchemParser.patterns.match_('digits', buffer.d || "");
              if (isAfterD && c1 && c1.remainder==='') {
                mhchemParser.concatArray(ret, mhchemParser.actions['d='](buffer, m));
                mhchemParser.concatArray(ret, this['output'](buffer));
              } else {
                mhchemParser.concatArray(ret, this['output'](buffer));
                mhchemParser.concatArray(ret, mhchemParser.actions['bond'](buffer, m, "-"));
              }
            }
            return ret;
          },
          'a to o': function (buffer) {
            buffer.o = buffer.a;
            buffer.a = undefined;
          },
          'sb=true': function (buffer) { buffer.sb = true; },
          'sb=false': function (buffer) { buffer.sb = false; },
          'beginsWithBond=true': function (buffer) { buffer['beginsWithBond'] = true; },
          'beginsWithBond=false': function (buffer) { buffer['beginsWithBond'] = false; },
          'parenthesisLevel++': function (buffer) { buffer['parenthesisLevel']++; },
          'parenthesisLevel--': function (buffer) { buffer['parenthesisLevel']--; },
          'state of aggregation': function (buffer, m) {
            return { type_: 'state of aggregation', p1: mhchemParser.go(m, 'o') };
          },
          'comma': function (buffer, m) {
            var a = m.replace(/\s*$/, '');
            var withSpace = (a !== m);
            if (withSpace  &&  buffer['parenthesisLevel'] === 0) {
              return { type_: 'comma enumeration L', p1: a };
            } else {
              return { type_: 'comma enumeration M', p1: a };
            }
          },
          'output': function (buffer, m, entityFollows) {
            // entityFollows:
            //   undefined = if we have nothing else to output, also ignore the just read space (buffer.sb)
            //   1 = an entity follows, never omit the space if there was one just read before (can only apply to state 1)
            //   2 = 1 + the entity can have an amount, so output a\, instead of converting it to o (can only apply to states a|as)
            /** @type {ParserOutput | ParserOutput[]} */
            var ret;
            if (!buffer.r) {
              ret = [];
              if (!buffer.a && !buffer.b && !buffer.p && !buffer.o && !buffer.q && !buffer.d && !entityFollows) {
                //ret = [];
              } else {
                if (buffer.sb) {
                  ret.push({ type_: 'entitySkip' });
                }
                if (!buffer.o && !buffer.q && !buffer.d && !buffer.b && !buffer.p && entityFollows!==2) {
                  buffer.o = buffer.a;
                  buffer.a = undefined;
                } else if (!buffer.o && !buffer.q && !buffer.d && (buffer.b || buffer.p)) {
                  buffer.o = buffer.a;
                  buffer.d = buffer.b;
                  buffer.q = buffer.p;
                  buffer.a = buffer.b = buffer.p = undefined;
                } else {
                  if (buffer.o && buffer.dType==='kv' && mhchemParser.patterns.match_('d-oxidation$', buffer.d || "")) {
                    buffer.dType = 'oxidation';
                  } else if (buffer.o && buffer.dType==='kv' && !buffer.q) {
                    buffer.dType = undefined;
                  }
                }
                ret.push({
                  type_: 'chemfive',
                  a: mhchemParser.go(buffer.a, 'a'),
                  b: mhchemParser.go(buffer.b, 'bd'),
                  p: mhchemParser.go(buffer.p, 'pq'),
                  o: mhchemParser.go(buffer.o, 'o'),
                  q: mhchemParser.go(buffer.q, 'pq'),
                  d: mhchemParser.go(buffer.d, (buffer.dType === 'oxidation' ? 'oxidation' : 'bd')),
                  dType: buffer.dType
                });
              }
            } else {  // r
              /** @type {ParserOutput[]} */
              var rd;
              if (buffer.rdt === 'M') {
                rd = mhchemParser.go(buffer.rd, 'tex-math');
              } else if (buffer.rdt === 'T') {
                rd = [ { type_: 'text', p1: buffer.rd || "" } ];
              } else {
                rd = mhchemParser.go(buffer.rd);
              }
              /** @type {ParserOutput[]} */
              var rq;
              if (buffer.rqt === 'M') {
                rq = mhchemParser.go(buffer.rq, 'tex-math');
              } else if (buffer.rqt === 'T') {
                rq = [ { type_: 'text', p1: buffer.rq || ""} ];
              } else {
                rq = mhchemParser.go(buffer.rq);
              }
              ret = {
                type_: 'arrow',
                r: buffer.r,
                rd: rd,
                rq: rq
              };
            }
            for (var p in buffer) {
              if (p !== 'parenthesisLevel'  &&  p !== 'beginsWithBond') {
                delete buffer[p];
              }
            }
            return ret;
          },
          'oxidation-output': function (buffer, m) {
            var ret = [ "{" ];
            mhchemParser.concatArray(ret, mhchemParser.go(m, 'oxidation'));
            ret.push("}");
            return ret;
          },
          'frac-output': function (buffer, m) {
            return { type_: 'frac-ce', p1: mhchemParser.go(m[0]), p2: mhchemParser.go(m[1]) };
          },
          'overset-output': function (buffer, m) {
            return { type_: 'overset', p1: mhchemParser.go(m[0]), p2: mhchemParser.go(m[1]) };
          },
          'underset-output': function (buffer, m) {
            return { type_: 'underset', p1: mhchemParser.go(m[0]), p2: mhchemParser.go(m[1]) };
          },
          'underbrace-output': function (buffer, m) {
            return { type_: 'underbrace', p1: mhchemParser.go(m[0]), p2: mhchemParser.go(m[1]) };
          },
          'color-output': function (buffer, m) {
            return { type_: 'color', color1: m[0], color2: mhchemParser.go(m[1]) };
          },
          'r=': function (buffer, m) { buffer.r = m; },
          'rdt=': function (buffer, m) { buffer.rdt = m; },
          'rd=': function (buffer, m) { buffer.rd = m; },
          'rqt=': function (buffer, m) { buffer.rqt = m; },
          'rq=': function (buffer, m) { buffer.rq = m; },
          'operator': function (buffer, m, p1) { return { type_: 'operator', kind_: (p1 || m) }; }
        }
      },
      'a': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': {} },
          '1/2$': {
            '0': { action_: '1/2' } },
          'else': {
            '0': { nextState: '1', revisit: true } },
          '$(...)$': {
            '*': { action_: 'tex-math tight', nextState: '1' } },
          ',': {
            '*': { action_: { type_: 'insert', option: 'commaDecimal' } } },
          'else2': {
            '*': { action_: 'copy' } }
        }),
        actions: {}
      },
      'o': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': {} },
          '1/2$': {
            '0': { action_: '1/2' } },
          'else': {
            '0': { nextState: '1', revisit: true } },
          'letters': {
            '*': { action_: 'rm' } },
          '\\ca': {
            '*': { action_: { type_: 'insert', option: 'circa' } } },
          '\\x{}{}|\\x{}|\\x': {
            '*': { action_: 'copy' } },
          '${(...)}$|$(...)$': {
            '*': { action_: 'tex-math' } },
          '{(...)}': {
            '*': { action_: '{text}' } },
          'else2': {
            '*': { action_: 'copy' } }
        }),
        actions: {}
      },
      'text': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': { action_: 'output' } },
          '{...}': {
            '*': { action_: 'text=' } },
          '${(...)}$|$(...)$': {
            '*': { action_: 'tex-math' } },
          '\\greek': {
            '*': { action_: [ 'output', 'rm' ] } },
          '\\,|\\x{}{}|\\x{}|\\x': {
            '*': { action_: [ 'output', 'copy' ] } },
          'else': {
            '*': { action_: 'text=' } }
        }),
        actions: {
          'output': function (buffer) {
            if (buffer.text_) {
              /** @type {ParserOutput} */
              var ret = { type_: 'text', p1: buffer.text_ };
              for (var p in buffer) { delete buffer[p]; }
              return ret;
            }
          }
        }
      },
      'pq': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': {} },
          'state of aggregation $': {
            '*': { action_: 'state of aggregation' } },
          'i$': {
            '0': { nextState: '!f', revisit: true } },
          '(KV letters),': {
            '0': { action_: 'rm', nextState: '0' } },
          'formula$': {
            '0': { nextState: 'f', revisit: true } },
          '1/2$': {
            '0': { action_: '1/2' } },
          'else': {
            '0': { nextState: '!f', revisit: true } },
          '${(...)}$|$(...)$': {
            '*': { action_: 'tex-math' } },
          '{(...)}': {
            '*': { action_: 'text' } },
          'a-z': {
            'f': { action_: 'tex-math' } },
          'letters': {
            '*': { action_: 'rm' } },
          '-9.,9': {
            '*': { action_: '9,9'  } },
          ',': {
            '*': { action_: { type_: 'insert+p1', option: 'comma enumeration S' } } },
          '\\color{(...)}{(...)}1|\\color(...){(...)}2': {
            '*': { action_: 'color-output' } },
          '\\color{(...)}0': {
            '*': { action_: 'color0-output' } },
          '\\ce{(...)}': {
            '*': { action_: 'ce' } },
          '\\,|\\x{}{}|\\x{}|\\x': {
            '*': { action_: 'copy' } },
          'else2': {
            '*': { action_: 'copy' } }
        }),
        actions: {
          'state of aggregation': function (buffer, m) {
            return { type_: 'state of aggregation subscript', p1: mhchemParser.go(m, 'o') };
          },
          'color-output': function (buffer, m) {
            return { type_: 'color', color1: m[0], color2: mhchemParser.go(m[1], 'pq') };
          }
        }
      },
      'bd': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': {} },
          'x$': {
            '0': { nextState: '!f', revisit: true } },
          'formula$': {
            '0': { nextState: 'f', revisit: true } },
          'else': {
            '0': { nextState: '!f', revisit: true } },
          '-9.,9 no missing 0': {
            '*': { action_: '9,9' } },
          '.': {
            '*': { action_: { type_: 'insert', option: 'electron dot' } } },
          'a-z': {
            'f': { action_: 'tex-math' } },
          'x': {
            '*': { action_: { type_: 'insert', option: 'KV x' } } },
          'letters': {
            '*': { action_: 'rm' } },
          '\'': {
            '*': { action_: { type_: 'insert', option: 'prime' } } },
          '${(...)}$|$(...)$': {
            '*': { action_: 'tex-math' } },
          '{(...)}': {
            '*': { action_: 'text' } },
          '\\color{(...)}{(...)}1|\\color(...){(...)}2': {
            '*': { action_: 'color-output' } },
          '\\color{(...)}0': {
            '*': { action_: 'color0-output' } },
          '\\ce{(...)}': {
            '*': { action_: 'ce' } },
          '\\,|\\x{}{}|\\x{}|\\x': {
            '*': { action_: 'copy' } },
          'else2': {
            '*': { action_: 'copy' } }
        }),
        actions: {
          'color-output': function (buffer, m) {
            return { type_: 'color', color1: m[0], color2: mhchemParser.go(m[1], 'bd') };
          }
        }
      },
      'oxidation': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': {} },
          'roman numeral': {
            '*': { action_: 'roman-numeral' } },
          '${(...)}$|$(...)$': {
            '*': { action_: 'tex-math' } },
          'else': {
            '*': { action_: 'copy' } }
        }),
        actions: {
          'roman-numeral': function (buffer, m) { return { type_: 'roman numeral', p1: m || "" }; }
        }
      },
      'tex-math': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': { action_: 'output' } },
          '\\ce{(...)}': {
            '*': { action_: [ 'output', 'ce' ] } },
          '{...}|\\,|\\x{}{}|\\x{}|\\x': {
            '*': { action_: 'o=' } },
          'else': {
            '*': { action_: 'o=' } }
        }),
        actions: {
          'output': function (buffer) {
            if (buffer.o) {
              /** @type {ParserOutput} */
              var ret = { type_: 'tex-math', p1: buffer.o };
              for (var p in buffer) { delete buffer[p]; }
              return ret;
            }
          }
        }
      },
      'tex-math tight': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': { action_: 'output' } },
          '\\ce{(...)}': {
            '*': { action_: [ 'output', 'ce' ] } },
          '{...}|\\,|\\x{}{}|\\x{}|\\x': {
            '*': { action_: 'o=' } },
          '-|+': {
            '*': { action_: 'tight operator' } },
          'else': {
            '*': { action_: 'o=' } }
        }),
        actions: {
          'tight operator': function (buffer, m) { buffer.o = (buffer.o || "") + "{"+m+"}"; },
          'output': function (buffer) {
            if (buffer.o) {
              /** @type {ParserOutput} */
              var ret = { type_: 'tex-math', p1: buffer.o };
              for (var p in buffer) { delete buffer[p]; }
              return ret;
            }
          }
        }
      },
      '9,9': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': {} },
          ',': {
            '*': { action_: 'comma' } },
          'else': {
            '*': { action_: 'copy' } }
        }),
        actions: {
          'comma': function () { return { type_: 'commaDecimal' }; }
        }
      },
      //#endregion
      //
      // \pu state machines
      //
      //#region pu
      'pu': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': { action_: 'output' } },
          'space$': {
            '*': { action_: [ 'output', 'space' ] } },
          '{[(|)]}': {
            '0|a': { action_: 'copy' } },
          '(-)(9)^(-9)': {
            '0': { action_: 'number^', nextState: 'a' } },
          '(-)(9.,9)(e)(99)': {
            '0': { action_: 'enumber', nextState: 'a' } },
          'space': {
            '0|a': {} },
          'pm-operator': {
            '0|a': { action_: { type_: 'operator', option: '\\pm' }, nextState: '0' } },
          'operator': {
            '0|a': { action_: 'copy', nextState: '0' } },
          '//': {
            'd': { action_: 'o=', nextState: '/' } },
          '/': {
            'd': { action_: 'o=', nextState: '/' } },
          '{...}|else': {
            '0|d': { action_: 'd=', nextState: 'd' },
            'a': { action_: [ 'space', 'd=' ], nextState: 'd' },
            '/|q': { action_: 'q=', nextState: 'q' } }
        }),
        actions: {
          'enumber': function (buffer, m) {
            /** @type {ParserOutput[]} */
            var ret = [];
            if (m[0] === "+-"  ||  m[0] === "+/-") {
              ret.push("\\pm ");
            } else if (m[0]) {
              ret.push(m[0]);
            }
            if (m[1]) {
              mhchemParser.concatArray(ret, mhchemParser.go(m[1], 'pu-9,9'));
              if (m[2]) {
                if (m[2].match(/[,.]/)) {
                  mhchemParser.concatArray(ret, mhchemParser.go(m[2], 'pu-9,9'));
                } else {
                  ret.push(m[2]);
                }
              }
              m[3] = m[4] || m[3];
              if (m[3]) {
                m[3] = m[3].trim();
                if (m[3] === "e"  ||  m[3].substr(0, 1) === "*") {
                  ret.push({ type_: 'cdot' });
                } else {
                  ret.push({ type_: 'times' });
                }
              }
            }
            if (m[3]) {
              ret.push("10^{"+m[5]+"}");
            }
            return ret;
          },
          'number^': function (buffer, m) {
            /** @type {ParserOutput[]} */
            var ret = [];
            if (m[0] === "+-"  ||  m[0] === "+/-") {
              ret.push("\\pm ");
            } else if (m[0]) {
              ret.push(m[0]);
            }
            mhchemParser.concatArray(ret, mhchemParser.go(m[1], 'pu-9,9'));
            ret.push("^{"+m[2]+"}");
            return ret;
          },
          'operator': function (buffer, m, p1) { return { type_: 'operator', kind_: (p1 || m) }; },
          'space': function () { return { type_: 'pu-space-1' }; },
          'output': function (buffer) {
            /** @type {ParserOutput | ParserOutput[]} */
            var ret;
            var md = mhchemParser.patterns.match_('{(...)}', buffer.d || "");
            if (md  &&  md.remainder === '') { buffer.d = md.match_; }
            var mq = mhchemParser.patterns.match_('{(...)}', buffer.q || "");
            if (mq  &&  mq.remainder === '') { buffer.q = mq.match_; }
            if (buffer.d) {
              buffer.d = buffer.d.replace(/\u00B0C|\^oC|\^{o}C/g, "{}^{\\circ}C");
              buffer.d = buffer.d.replace(/\u00B0F|\^oF|\^{o}F/g, "{}^{\\circ}F");
            }
            if (buffer.q) {  // fraction
              buffer.q = buffer.q.replace(/\u00B0C|\^oC|\^{o}C/g, "{}^{\\circ}C");
              buffer.q = buffer.q.replace(/\u00B0F|\^oF|\^{o}F/g, "{}^{\\circ}F");
              var b5 = {
                d: mhchemParser.go(buffer.d, 'pu'),
                q: mhchemParser.go(buffer.q, 'pu')
              };
              if (buffer.o === '//') {
                ret = { type_: 'pu-frac', p1: b5.d, p2: b5.q };
              } else {
                ret = b5.d;
                if (b5.d.length > 1  ||  b5.q.length > 1) {
                  ret.push({ type_: ' / ' });
                } else {
                  ret.push({ type_: '/' });
                }
                mhchemParser.concatArray(ret, b5.q);
              }
            } else {  // no fraction
              ret = mhchemParser.go(buffer.d, 'pu-2');
            }
            for (var p in buffer) { delete buffer[p]; }
            return ret;
          }
        }
      },
      'pu-2': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '*': { action_: 'output' } },
          '*': {
            '*': { action_: [ 'output', 'cdot' ], nextState: '0' } },
          '\\x': {
            '*': { action_: 'rm=' } },
          'space': {
            '*': { action_: [ 'output', 'space' ], nextState: '0' } },
          '^{(...)}|^(-1)': {
            '1': { action_: '^(-1)' } },
          '-9.,9': {
            '0': { action_: 'rm=', nextState: '0' },
            '1': { action_: '^(-1)', nextState: '0' } },
          '{...}|else': {
            '*': { action_: 'rm=', nextState: '1' } }
        }),
        actions: {
          'cdot': function () { return { type_: 'tight cdot' }; },
          '^(-1)': function (buffer, m) { buffer.rm += "^{"+m+"}"; },
          'space': function () { return { type_: 'pu-space-2' }; },
          'output': function (buffer) {
            /** @type {ParserOutput | ParserOutput[]} */
            var ret = [];
            if (buffer.rm) {
              var mrm = mhchemParser.patterns.match_('{(...)}', buffer.rm || "");
              if (mrm  &&  mrm.remainder === '') {
                ret = mhchemParser.go(mrm.match_, 'pu');
              } else {
                ret = { type_: 'rm', p1: buffer.rm };
              }
            }
            for (var p in buffer) { delete buffer[p]; }
            return ret;
          }
        }
      },
      'pu-9,9': {
        transitions: mhchemParser.createTransitions({
          'empty': {
            '0': { action_: 'output-0' },
            'o': { action_: 'output-o' } },
          ',': {
            '0': { action_: [ 'output-0', 'comma' ], nextState: 'o' } },
          '.': {
            '0': { action_: [ 'output-0', 'copy' ], nextState: 'o' } },
          'else': {
            '*': { action_: 'text=' } }
        }),
        actions: {
          'comma': function () { return { type_: 'commaDecimal' }; },
          'output-0': function (buffer) {
            /** @type {ParserOutput[]} */
            var ret = [];
            buffer.text_ = buffer.text_ || "";
            if (buffer.text_.length > 4) {
              var a = buffer.text_.length % 3;
              if (a === 0) { a = 3; }
              for (var i=buffer.text_.length-3; i>0; i-=3) {
                ret.push(buffer.text_.substr(i, 3));
                ret.push({ type_: '1000 separator' });
              }
              ret.push(buffer.text_.substr(0, a));
              ret.reverse();
            } else {
              ret.push(buffer.text_);
            }
            for (var p in buffer) { delete buffer[p]; }
            return ret;
          },
          'output-o': function (buffer) {
            /** @type {ParserOutput[]} */
            var ret = [];
            buffer.text_ = buffer.text_ || "";
            if (buffer.text_.length > 4) {
              var a = buffer.text_.length - 3;
              for (var i=0; i<a; i+=3) {
                ret.push(buffer.text_.substr(i, 3));
                ret.push({ type_: '1000 separator' });
              }
              ret.push(buffer.text_.substr(i));
            } else {
              ret.push(buffer.text_);
            }
            for (var p in buffer) { delete buffer[p]; }
            return ret;
          }
        }
      }
      //#endregion
    };
  
    //
    // texify: Take MhchemParser output and convert it to TeX
    //
    /** @type {Texify} */
    var texify = {
      go: function (input, isInner) {  // (recursive, max 4 levels)
        if (!input) { return ""; }
        var res = "";
        var cee = false;
        for (var i=0; i < input.length; i++) {
          var inputi = input[i];
          if (typeof inputi === "string") {
            res += inputi;
          } else {
            res += texify._go2(inputi);
            if (inputi.type_ === '1st-level escape') { cee = true; }
          }
        }
        if (!isInner && !cee && res) {
          res = "{" + res + "}";
        }
        return res;
      },
      _goInner: function (input) {
        if (!input) { return input; }
        return texify.go(input, true);
      },
      _go2: function (buf) {
        /** @type {undefined | string} */
        var res;
        switch (buf.type_) {
          case 'chemfive':
            res = "";
            var b5 = {
              a: texify._goInner(buf.a),
              b: texify._goInner(buf.b),
              p: texify._goInner(buf.p),
              o: texify._goInner(buf.o),
              q: texify._goInner(buf.q),
              d: texify._goInner(buf.d)
            };
            //
            // a
            //
            if (b5.a) {
              if (b5.a.match(/^[+\-]/)) { b5.a = "{"+b5.a+"}"; }
              res += b5.a + "\\,";
            }
            //
            // b and p
            //
            if (b5.b || b5.p) {
              res += "{\\vphantom{X}}";
              res += "^{\\hphantom{"+(b5.b||"")+"}}_{\\hphantom{"+(b5.p||"")+"}}";
              res += "{\\vphantom{X}}";
              res += "^{\\smash[t]{\\vphantom{2}}\\mathllap{"+(b5.b||"")+"}}";
              res += "_{\\vphantom{2}\\mathllap{\\smash[t]{"+(b5.p||"")+"}}}";
            }
            //
            // o
            //
            if (b5.o) {
              if (b5.o.match(/^[+\-]/)) { b5.o = "{"+b5.o+"}"; }
              res += b5.o;
            }
            //
            // q and d
            //
            if (buf.dType === 'kv') {
              if (b5.d || b5.q) {
                res += "{\\vphantom{X}}";
              }
              if (b5.d) {
                res += "^{"+b5.d+"}";
              }
              if (b5.q) {
                res += "_{\\smash[t]{"+b5.q+"}}";
              }
            } else if (buf.dType === 'oxidation') {
              if (b5.d) {
                res += "{\\vphantom{X}}";
                res += "^{"+b5.d+"}";
              }
              if (b5.q) {
                res += "{\\vphantom{X}}";
                res += "_{\\smash[t]{"+b5.q+"}}";
              }
            } else {
              if (b5.q) {
                res += "{\\vphantom{X}}";
                res += "_{\\smash[t]{"+b5.q+"}}";
              }
              if (b5.d) {
                res += "{\\vphantom{X}}";
                res += "^{"+b5.d+"}";
              }
            }
            break;
          case 'rm':
            res = "\\mathrm{"+buf.p1+"}";
            break;
          case 'text':
            if (buf.p1.match(/[\^_]/)) {
              buf.p1 = buf.p1.replace(" ", "~").replace("-", "\\text{-}");
              res = "\\mathrm{"+buf.p1+"}";
            } else {
              res = "\\text{"+buf.p1+"}";
            }
            break;
          case 'roman numeral':
            res = "\\mathrm{"+buf.p1+"}";
            break;
          case 'state of aggregation':
            res = "\\mskip2mu "+texify._goInner(buf.p1);
            break;
          case 'state of aggregation subscript':
            res = "\\mskip1mu "+texify._goInner(buf.p1);
            break;
          case 'bond':
            res = texify._getBond(buf.kind_);
            if (!res) {
              throw ["MhchemErrorBond", "mhchem Error. Unknown bond type (" + buf.kind_ + ")"];
            }
            break;
          case 'frac':
            var c = "\\frac{" + buf.p1 + "}{" + buf.p2 + "}";
            res = "\\mathchoice{\\textstyle"+c+"}{"+c+"}{"+c+"}{"+c+"}";
            break;
          case 'pu-frac':
            var d = "\\frac{" + texify._goInner(buf.p1) + "}{" + texify._goInner(buf.p2) + "}";
            res = "\\mathchoice{\\textstyle"+d+"}{"+d+"}{"+d+"}{"+d+"}";
            break;
          case 'tex-math':
            res = buf.p1 + " ";
            break;
          case 'frac-ce':
            res = "\\frac{" + texify._goInner(buf.p1) + "}{" + texify._goInner(buf.p2) + "}";
            break;
          case 'overset':
            res = "\\overset{" + texify._goInner(buf.p1) + "}{" + texify._goInner(buf.p2) + "}";
            break;
          case 'underset':
            res = "\\underset{" + texify._goInner(buf.p1) + "}{" + texify._goInner(buf.p2) + "}";
            break;
          case 'underbrace':
            res =  "\\underbrace{" + texify._goInner(buf.p1) + "}_{" + texify._goInner(buf.p2) + "}";
            break;
          case 'color':
            res = "{\\color{" + buf.color1 + "}{" + texify._goInner(buf.color2) + "}}";
            break;
          case 'color0':
            res = "\\color{" + buf.color + "}";
            break;
          case 'arrow':
            var b6 = {
              rd: texify._goInner(buf.rd),
              rq: texify._goInner(buf.rq)
            };
            var arrow = "\\x" + texify._getArrow(buf.r);
            if (b6.rq) { arrow += "[{" + b6.rq + "}]"; }
            if (b6.rd) {
              arrow += "{" + b6.rd + "}";
            } else {
              arrow += "{}";
            }
            res = arrow;
            break;
          case 'operator':
            res = texify._getOperator(buf.kind_);
            break;
          case '1st-level escape':
            res = buf.p1+" ";  // &, \\\\, \\hlin
            break;
          case 'space':
            res = " ";
            break;
          case 'entitySkip':
            res = "~";
            break;
          case 'pu-space-1':
            res = "~";
            break;
          case 'pu-space-2':
            res = "\\mkern3mu ";
            break;
          case '1000 separator':
            res = "\\mkern2mu ";
            break;
          case 'commaDecimal':
            res = "{,}";
            break;
            case 'comma enumeration L':
            res = "{"+buf.p1+"}\\mkern6mu ";
            break;
          case 'comma enumeration M':
            res = "{"+buf.p1+"}\\mkern3mu ";
            break;
          case 'comma enumeration S':
            res = "{"+buf.p1+"}\\mkern1mu ";
            break;
          case 'hyphen':
            res = "\\text{-}";
            break;
          case 'addition compound':
            res = "\\,{\\cdot}\\,";
            break;
          case 'electron dot':
            res = "\\mkern1mu \\bullet\\mkern1mu ";
            break;
          case 'KV x':
            res = "{\\times}";
            break;
          case 'prime':
            res = "\\prime ";
            break;
          case 'cdot':
            res = "\\cdot ";
            break;
          case 'tight cdot':
            res = "\\mkern1mu{\\cdot}\\mkern1mu ";
            break;
          case 'times':
            res = "\\times ";
            break;
          case 'circa':
            res = "{\\sim}";
            break;
          case '^':
            res = "uparrow";
            break;
          case 'v':
            res = "downarrow";
            break;
          case 'ellipsis':
            res = "\\ldots ";
            break;
          case '/':
            res = "/";
            break;
          case ' / ':
            res = "\\,/\\,";
            break;
          default:
            assertNever(buf);
            throw ["MhchemBugT", "mhchem bug T. Please report."];  // Missing texify rule or unknown MhchemParser output
        }
        assertString(res);
        return res;
      },
      _getArrow: function (a) {
        switch (a) {
          case "->": return "rightarrow";
          case "\u2192": return "rightarrow";
          case "\u27F6": return "rightarrow";
          case "<-": return "leftarrow";
          case "<->": return "leftrightarrow";
          case "<-->": return "rightleftarrows";
          case "<=>": return "rightleftharpoons";
          case "\u21CC": return "rightleftharpoons";
          case "<=>>": return "rightequilibrium";
          case "<<=>": return "leftequilibrium";
          default:
            assertNever(a);
            throw ["MhchemBugT", "mhchem bug T. Please report."];
        }
      },
      _getBond: function (a) {
        switch (a) {
          case "-": return "{-}";
          case "1": return "{-}";
          case "=": return "{=}";
          case "2": return "{=}";
          case "#": return "{\\equiv}";
          case "3": return "{\\equiv}";
          case "~": return "{\\tripledash}";
          case "~-": return "{\\mathrlap{\\raisebox{-.1em}{$-$}}\\raisebox{.1em}{$\\tripledash$}}";
          case "~=": return "{\\mathrlap{\\raisebox{-.2em}{$-$}}\\mathrlap{\\raisebox{.2em}{$\\tripledash$}}-}";
          case "~--": return "{\\mathrlap{\\raisebox{-.2em}{$-$}}\\mathrlap{\\raisebox{.2em}{$\\tripledash$}}-}";
          case "-~-": return "{\\mathrlap{\\raisebox{-.2em}{$-$}}\\mathrlap{\\raisebox{.2em}{$-$}}\\tripledash}";
          case "...": return "{{\\cdot}{\\cdot}{\\cdot}}";
          case "....": return "{{\\cdot}{\\cdot}{\\cdot}{\\cdot}}";
          case "->": return "{\\rightarrow}";
          case "<-": return "{\\leftarrow}";
          case "<": return "{<}";
          case ">": return "{>}";
          default:
            assertNever(a);
            throw ["MhchemBugT", "mhchem bug T. Please report."];
        }
      },
      _getOperator: function (a) {
        switch (a) {
          case "+": return " {}+{} ";
          case "-": return " {}-{} ";
          case "=": return " {}={} ";
          case "<": return " {}<{} ";
          case ">": return " {}>{} ";
          case "<<": return " {}\\ll{} ";
          case ">>": return " {}\\gg{} ";
          case "\\pm": return " {}\\pm{} ";
          case "\\approx": return " {}\\approx{} ";
          case "$\\approx$": return " {}\\approx{} ";
          case "v": return " \\downarrow{} ";
          case "(v)": return " \\downarrow{} ";
          case "^": return " \\uparrow{} ";
          case "(^)": return " \\uparrow{} ";
          default:
            assertNever(a);
            throw ["MhchemBugT", "mhchem bug T. Please report."];
        }
      }
    };
  
    //
    // Helpers for code anaylsis
    // Will show type error at calling position
    //
    /** @param {number} a */
    function assertNever(a) {}
    /** @param {string} a */
    function assertString(a) {}