langchain-core/src/utils/sax-js/sax.ts

// @ts-nocheck

// Inlined to deal with portability issues
// Originally from: https://github.com/isaacs/sax-js

const initializeSax = function () {
  const sax: any = {};
  sax.parser = function (strict, opt) {
    return new SAXParser(strict, opt);
  };
  sax.SAXParser = SAXParser;
  sax.SAXStream = SAXStream;
  sax.createStream = createStream;

  // When we pass the MAX_BUFFER_LENGTH position, start checking for buffer overruns.
  // When we check, schedule the next check for MAX_BUFFER_LENGTH - (max(buffer lengths)),
  // since that's the earliest that a buffer overrun could occur.  This way, checks are
  // as rare as required, but as often as necessary to ensure never crossing this bound.
  // Furthermore, buffers are only tested at most once per write(), so passing a very
  // large string into write() might have undesirable effects, but this is manageable by
  // the caller, so it is assumed to be safe.  Thus, a call to write() may, in the extreme
  // edge case, result in creating at most one complete copy of the string passed in.
  // Set to Infinity to have unlimited buffers.
  sax.MAX_BUFFER_LENGTH = 64 * 1024;

  const buffers = [
    "comment",
    "sgmlDecl",
    "textNode",
    "tagName",
    "doctype",
    "procInstName",
    "procInstBody",
    "entity",
    "attribName",
    "attribValue",
    "cdata",
    "script",
  ];

  sax.EVENTS = [
    "text",
    "processinginstruction",
    "sgmldeclaration",
    "doctype",
    "comment",
    "opentagstart",
    "attribute",
    "opentag",
    "closetag",
    "opencdata",
    "cdata",
    "closecdata",
    "error",
    "end",
    "ready",
    "script",
    "opennamespace",
    "closenamespace",
  ];

  function SAXParser(strict, opt) {
    if (!(this instanceof SAXParser)) {
      return new SAXParser(strict, opt);
    }

    var parser = this;
    clearBuffers(parser);
    parser.q = parser.c = "";
    parser.bufferCheckPosition = sax.MAX_BUFFER_LENGTH;
    parser.opt = opt || {};
    parser.opt.lowercase = parser.opt.lowercase || parser.opt.lowercasetags;
    parser.looseCase = parser.opt.lowercase ? "toLowerCase" : "toUpperCase";
    parser.tags = [];
    parser.closed = parser.closedRoot = parser.sawRoot = false;
    parser.tag = parser.error = null;
    parser.strict = !!strict;
    parser.noscript = !!(strict || parser.opt.noscript);
    parser.state = S.BEGIN;
    parser.strictEntities = parser.opt.strictEntities;
    parser.ENTITIES = parser.strictEntities
      ? Object.create(sax.XML_ENTITIES)
      : Object.create(sax.ENTITIES);
    parser.attribList = [];

    // namespaces form a prototype chain.
    // it always points at the current tag,
    // which protos to its parent tag.
    if (parser.opt.xmlns) {
      parser.ns = Object.create(rootNS);
    }

    // mostly just for error reporting
    parser.trackPosition = parser.opt.position !== false;
    if (parser.trackPosition) {
      parser.position = parser.line = parser.column = 0;
    }
    emit(parser, "onready");
  }

  if (!Object.create) {
    Object.create = function (o) {
      function F() {}
      F.prototype = o;
      var newf = new F();
      return newf;
    };
  }

  if (!Object.keys) {
    Object.keys = function (o) {
      var a = [];
      for (var i in o) if (o.hasOwnProperty(i)) a.push(i);
      return a;
    };
  }

  function checkBufferLength(parser) {
    var maxAllowed = Math.max(sax.MAX_BUFFER_LENGTH, 10);
    var maxActual = 0;
    for (var i = 0, l = buffers.length; i < l; i++) {
      var len = parser[buffers[i]].length;
      if (len > maxAllowed) {
        // Text/cdata nodes can get big, and since they're buffered,
        // we can get here under normal conditions.
        // Avoid issues by emitting the text node now,
        // so at least it won't get any bigger.
        switch (buffers[i]) {
          case "textNode":
            closeText(parser);
            break;

          case "cdata":
            emitNode(parser, "oncdata", parser.cdata);
            parser.cdata = "";
            break;

          case "script":
            emitNode(parser, "onscript", parser.script);
            parser.script = "";
            break;

          default:
            error(parser, "Max buffer length exceeded: " + buffers[i]);
        }
      }
      maxActual = Math.max(maxActual, len);
    }
    // schedule the next check for the earliest possible buffer overrun.
    var m = sax.MAX_BUFFER_LENGTH - maxActual;
    parser.bufferCheckPosition = m + parser.position;
  }

  function clearBuffers(parser) {
    for (var i = 0, l = buffers.length; i < l; i++) {
      parser[buffers[i]] = "";
    }
  }

  function flushBuffers(parser) {
    closeText(parser);
    if (parser.cdata !== "") {
      emitNode(parser, "oncdata", parser.cdata);
      parser.cdata = "";
    }
    if (parser.script !== "") {
      emitNode(parser, "onscript", parser.script);
      parser.script = "";
    }
  }

  SAXParser.prototype = {
    end: function () {
      end(this);
    },
    write: write,
    resume: function () {
      this.error = null;
      return this;
    },
    close: function () {
      return this.write(null);
    },
    flush: function () {
      flushBuffers(this);
    },
  };

  var Stream = ReadableStream;
  if (!Stream) Stream = function () {};

  var streamWraps = sax.EVENTS.filter(function (ev) {
    return ev !== "error" && ev !== "end";
  });

  function createStream(strict, opt) {
    return new SAXStream(strict, opt);
  }

  function SAXStream(strict, opt) {
    if (!(this instanceof SAXStream)) {
      return new SAXStream(strict, opt);
    }

    Stream.apply(this);

    this._parser = new SAXParser(strict, opt);
    this.writable = true;
    this.readable = true;

    var me = this;

    this._parser.onend = function () {
      me.emit("end");
    };

    this._parser.onerror = function (er) {
      me.emit("error", er);

      // if didn't throw, then means error was handled.
      // go ahead and clear error, so we can write again.
      me._parser.error = null;
    };

    this._decoder = null;

    streamWraps.forEach(function (ev) {
      Object.defineProperty(me, "on" + ev, {
        get: function () {
          return me._parser["on" + ev];
        },
        set: function (h) {
          if (!h) {
            me.removeAllListeners(ev);
            me._parser["on" + ev] = h;
            return h;
          }
          me.on(ev, h);
        },
        enumerable: true,
        configurable: false,
      });
    });
  }

  SAXStream.prototype = Object.create(Stream.prototype, {
    constructor: {
      value: SAXStream,
    },
  });

  SAXStream.prototype.write = function (data) {
    this._parser.write(data.toString());
    this.emit("data", data);
    return true;
  };

  SAXStream.prototype.end = function (chunk) {
    if (chunk && chunk.length) {
      this.write(chunk);
    }
    this._parser.end();
    return true;
  };

  SAXStream.prototype.on = function (ev, handler) {
    var me = this;
    if (!me._parser["on" + ev] && streamWraps.indexOf(ev) !== -1) {
      me._parser["on" + ev] = function () {
        var args =
          arguments.length === 1
            ? [arguments[0]]
            : Array.apply(null, arguments);
        args.splice(0, 0, ev);
        me.emit.apply(me, args);
      };
    }

    return Stream.prototype.on.call(me, ev, handler);
  };

  // this really needs to be replaced with character classes.
  // XML allows all manner of ridiculous numbers and digits.
  var CDATA = "[CDATA[";
  var DOCTYPE = "DOCTYPE";
  var XML_NAMESPACE = "http://www.w3.org/XML/1998/namespace";
  var XMLNS_NAMESPACE = "http://www.w3.org/2000/xmlns/";
  var rootNS = { xml: XML_NAMESPACE, xmlns: XMLNS_NAMESPACE };

  // http://www.w3.org/TR/REC-xml/#NT-NameStartChar
  // This implementation works on strings, a single character at a time
  // as such, it cannot ever support astral-plane characters (10000-EFFFF)
  // without a significant breaking change to either this  parser, or the
  // JavaScript language.  Implementation of an emoji-capable xml parser
  // is left as an exercise for the reader.
  var nameStart =
    /[:_A-Za-z\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02FF\u0370-\u037D\u037F-\u1FFF\u200C-\u200D\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD]/;

  var nameBody =
    /[:_A-Za-z\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02FF\u0370-\u037D\u037F-\u1FFF\u200C-\u200D\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD\u00B7\u0300-\u036F\u203F-\u2040.\d-]/;

  var entityStart =
    /[#:_A-Za-z\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02FF\u0370-\u037D\u037F-\u1FFF\u200C-\u200D\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD]/;
  var entityBody =
    /[#:_A-Za-z\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02FF\u0370-\u037D\u037F-\u1FFF\u200C-\u200D\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD\u00B7\u0300-\u036F\u203F-\u2040.\d-]/;

  function isWhitespace(c) {
    return c === " " || c === "\n" || c === "\r" || c === "\t";
  }

  function isQuote(c) {
    return c === '"' || c === "'";
  }

  function isAttribEnd(c) {
    return c === ">" || isWhitespace(c);
  }

  function isMatch(regex, c) {
    return regex.test(c);
  }

  function notMatch(regex, c) {
    return !isMatch(regex, c);
  }

  var S = 0;
  sax.STATE = {
    BEGIN: S++, // leading byte order mark or whitespace
    BEGIN_WHITESPACE: S++, // leading whitespace
    TEXT: S++, // general stuff
    TEXT_ENTITY: S++, // &amp and such.
    OPEN_WAKA: S++, // <
    SGML_DECL: S++, // <!BLARG
    SGML_DECL_QUOTED: S++, // <!BLARG foo "bar
    DOCTYPE: S++, // <!DOCTYPE
    DOCTYPE_QUOTED: S++, // <!DOCTYPE "//blah
    DOCTYPE_DTD: S++, // <!DOCTYPE "//blah" [ ...
    DOCTYPE_DTD_QUOTED: S++, // <!DOCTYPE "//blah" [ "foo
    COMMENT_STARTING: S++, // <!-
    COMMENT: S++, // <!--
    COMMENT_ENDING: S++, // <!-- blah -
    COMMENT_ENDED: S++, // <!-- blah --
    CDATA: S++, // <![CDATA[ something
    CDATA_ENDING: S++, // ]
    CDATA_ENDING_2: S++, // ]]
    PROC_INST: S++, // <?hi
    PROC_INST_BODY: S++, // <?hi there
    PROC_INST_ENDING: S++, // <?hi "there" ?
    OPEN_TAG: S++, // <strong
    OPEN_TAG_SLASH: S++, // <strong /
    ATTRIB: S++, // <a
    ATTRIB_NAME: S++, // <a foo
    ATTRIB_NAME_SAW_WHITE: S++, // <a foo _
    ATTRIB_VALUE: S++, // <a foo=
    ATTRIB_VALUE_QUOTED: S++, // <a foo="bar
    ATTRIB_VALUE_CLOSED: S++, // <a foo="bar"
    ATTRIB_VALUE_UNQUOTED: S++, // <a foo=bar
    ATTRIB_VALUE_ENTITY_Q: S++, // <foo bar="&quot;"
    ATTRIB_VALUE_ENTITY_U: S++, // <foo bar=&quot
    CLOSE_TAG: S++, // </a
    CLOSE_TAG_SAW_WHITE: S++, // </a   >
    SCRIPT: S++, // <script> ...
    SCRIPT_ENDING: S++, // <script> ... <
  };

  sax.XML_ENTITIES = {
    amp: "&",
    gt: ">",
    lt: "<",
    quot: '"',
    apos: "'",
  };

  sax.ENTITIES = {
    amp: "&",
    gt: ">",
    lt: "<",
    quot: '"',
    apos: "'",
    AElig: 198,
    Aacute: 193,
    Acirc: 194,
    Agrave: 192,
    Aring: 197,
    Atilde: 195,
    Auml: 196,
    Ccedil: 199,
    ETH: 208,
    Eacute: 201,
    Ecirc: 202,
    Egrave: 200,
    Euml: 203,
    Iacute: 205,
    Icirc: 206,
    Igrave: 204,
    Iuml: 207,
    Ntilde: 209,
    Oacute: 211,
    Ocirc: 212,
    Ograve: 210,
    Oslash: 216,
    Otilde: 213,
    Ouml: 214,
    THORN: 222,
    Uacute: 218,
    Ucirc: 219,
    Ugrave: 217,
    Uuml: 220,
    Yacute: 221,
    aacute: 225,
    acirc: 226,
    aelig: 230,
    agrave: 224,
    aring: 229,
    atilde: 227,
    auml: 228,
    ccedil: 231,
    eacute: 233,
    ecirc: 234,
    egrave: 232,
    eth: 240,
    euml: 235,
    iacute: 237,
    icirc: 238,
    igrave: 236,
    iuml: 239,
    ntilde: 241,
    oacute: 243,
    ocirc: 244,
    ograve: 242,
    oslash: 248,
    otilde: 245,
    ouml: 246,
    szlig: 223,
    thorn: 254,
    uacute: 250,
    ucirc: 251,
    ugrave: 249,
    uuml: 252,
    yacute: 253,
    yuml: 255,
    copy: 169,
    reg: 174,
    nbsp: 160,
    iexcl: 161,
    cent: 162,
    pound: 163,
    curren: 164,
    yen: 165,
    brvbar: 166,
    sect: 167,
    uml: 168,
    ordf: 170,
    laquo: 171,
    not: 172,
    shy: 173,
    macr: 175,
    deg: 176,
    plusmn: 177,
    sup1: 185,
    sup2: 178,
    sup3: 179,
    acute: 180,
    micro: 181,
    para: 182,
    middot: 183,
    cedil: 184,
    ordm: 186,
    raquo: 187,
    frac14: 188,
    frac12: 189,
    frac34: 190,
    iquest: 191,
    times: 215,
    divide: 247,
    OElig: 338,
    oelig: 339,
    Scaron: 352,
    scaron: 353,
    Yuml: 376,
    fnof: 402,
    circ: 710,
    tilde: 732,
    Alpha: 913,
    Beta: 914,
    Gamma: 915,
    Delta: 916,
    Epsilon: 917,
    Zeta: 918,
    Eta: 919,
    Theta: 920,
    Iota: 921,
    Kappa: 922,
    Lambda: 923,
    Mu: 924,
    Nu: 925,
    Xi: 926,
    Omicron: 927,
    Pi: 928,
    Rho: 929,
    Sigma: 931,
    Tau: 932,
    Upsilon: 933,
    Phi: 934,
    Chi: 935,
    Psi: 936,
    Omega: 937,
    alpha: 945,
    beta: 946,
    gamma: 947,
    delta: 948,
    epsilon: 949,
    zeta: 950,
    eta: 951,
    theta: 952,
    iota: 953,
    kappa: 954,
    lambda: 955,
    mu: 956,
    nu: 957,
    xi: 958,
    omicron: 959,
    pi: 960,
    rho: 961,
    sigmaf: 962,
    sigma: 963,
    tau: 964,
    upsilon: 965,
    phi: 966,
    chi: 967,
    psi: 968,
    omega: 969,
    thetasym: 977,
    upsih: 978,
    piv: 982,
    ensp: 8194,
    emsp: 8195,
    thinsp: 8201,
    zwnj: 8204,
    zwj: 8205,
    lrm: 8206,
    rlm: 8207,
    ndash: 8211,
    mdash: 8212,
    lsquo: 8216,
    rsquo: 8217,
    sbquo: 8218,
    ldquo: 8220,
    rdquo: 8221,
    bdquo: 8222,
    dagger: 8224,
    Dagger: 8225,
    bull: 8226,
    hellip: 8230,
    permil: 8240,
    prime: 8242,
    Prime: 8243,
    lsaquo: 8249,
    rsaquo: 8250,
    oline: 8254,
    frasl: 8260,
    euro: 8364,
    image: 8465,
    weierp: 8472,
    real: 8476,
    trade: 8482,
    alefsym: 8501,
    larr: 8592,
    uarr: 8593,
    rarr: 8594,
    darr: 8595,
    harr: 8596,
    crarr: 8629,
    lArr: 8656,
    uArr: 8657,
    rArr: 8658,
    dArr: 8659,
    hArr: 8660,
    forall: 8704,
    part: 8706,
    exist: 8707,
    empty: 8709,
    nabla: 8711,
    isin: 8712,
    notin: 8713,
    ni: 8715,
    prod: 8719,
    sum: 8721,
    minus: 8722,
    lowast: 8727,
    radic: 8730,
    prop: 8733,
    infin: 8734,
    ang: 8736,
    and: 8743,
    or: 8744,
    cap: 8745,
    cup: 8746,
    int: 8747,
    there4: 8756,
    sim: 8764,
    cong: 8773,
    asymp: 8776,
    ne: 8800,
    equiv: 8801,
    le: 8804,
    ge: 8805,
    sub: 8834,
    sup: 8835,
    nsub: 8836,
    sube: 8838,
    supe: 8839,
    oplus: 8853,
    otimes: 8855,
    perp: 8869,
    sdot: 8901,
    lceil: 8968,
    rceil: 8969,
    lfloor: 8970,
    rfloor: 8971,
    lang: 9001,
    rang: 9002,
    loz: 9674,
    spades: 9824,
    clubs: 9827,
    hearts: 9829,
    diams: 9830,
  };

  Object.keys(sax.ENTITIES).forEach(function (key) {
    var e = sax.ENTITIES[key];
    var s = typeof e === "number" ? String.fromCharCode(e) : e;
    sax.ENTITIES[key] = s;
  });

  for (var s in sax.STATE) {
    sax.STATE[sax.STATE[s]] = s;
  }

  // shorthand
  S = sax.STATE;

  function emit(parser, event, data) {
    parser[event] && parser[event](data);
  }

  function emitNode(parser, nodeType, data) {
    if (parser.textNode) closeText(parser);
    emit(parser, nodeType, data);
  }

  function closeText(parser) {
    parser.textNode = textopts(parser.opt, parser.textNode);
    if (parser.textNode) emit(parser, "ontext", parser.textNode);
    parser.textNode = "";
  }

  function textopts(opt, text) {
    if (opt.trim) text = text.trim();
    if (opt.normalize) text = text.replace(/\s+/g, " ");
    return text;
  }

  function error(parser, er) {
    closeText(parser);
    if (parser.trackPosition) {
      er +=
        "\nLine: " +
        parser.line +
        "\nColumn: " +
        parser.column +
        "\nChar: " +
        parser.c;
    }
    er = new Error(er);
    parser.error = er;
    emit(parser, "onerror", er);
    return parser;
  }

  function end(parser) {
    if (parser.sawRoot && !parser.closedRoot)
      strictFail(parser, "Unclosed root tag");
    if (
      parser.state !== S.BEGIN &&
      parser.state !== S.BEGIN_WHITESPACE &&
      parser.state !== S.TEXT
    ) {
      error(parser, "Unexpected end");
    }
    closeText(parser);
    parser.c = "";
    parser.closed = true;
    emit(parser, "onend");
    SAXParser.call(parser, parser.strict, parser.opt);
    return parser;
  }

  function strictFail(parser, message) {
    if (typeof parser !== "object" || !(parser instanceof SAXParser)) {
      throw new Error("bad call to strictFail");
    }
    if (parser.strict) {
      error(parser, message);
    }
  }

  function newTag(parser) {
    if (!parser.strict) parser.tagName = parser.tagName[parser.looseCase]();
    var parent = parser.tags[parser.tags.length - 1] || parser;
    var tag = (parser.tag = { name: parser.tagName, attributes: {} });

    // will be overridden if tag contails an xmlns="foo" or xmlns:foo="bar"
    if (parser.opt.xmlns) {
      tag.ns = parent.ns;
    }
    parser.attribList.length = 0;
    emitNode(parser, "onopentagstart", tag);
  }

  function qname(name, attribute) {
    var i = name.indexOf(":");
    var qualName = i < 0 ? ["", name] : name.split(":");
    var prefix = qualName[0];
    var local = qualName[1];

    // <x "xmlns"="http://foo">
    if (attribute && name === "xmlns") {
      prefix = "xmlns";
      local = "";
    }

    return { prefix: prefix, local: local };
  }

  function attrib(parser) {
    if (!parser.strict) {
      parser.attribName = parser.attribName[parser.looseCase]();
    }

    if (
      parser.attribList.indexOf(parser.attribName) !== -1 ||
      parser.tag.attributes.hasOwnProperty(parser.attribName)
    ) {
      parser.attribName = parser.attribValue = "";
      return;
    }

    if (parser.opt.xmlns) {
      var qn = qname(parser.attribName, true);
      var prefix = qn.prefix;
      var local = qn.local;

      if (prefix === "xmlns") {
        // namespace binding attribute. push the binding into scope
        if (local === "xml" && parser.attribValue !== XML_NAMESPACE) {
          strictFail(
            parser,
            "xml: prefix must be bound to " +
              XML_NAMESPACE +
              "\n" +
              "Actual: " +
              parser.attribValue
          );
        } else if (
          local === "xmlns" &&
          parser.attribValue !== XMLNS_NAMESPACE
        ) {
          strictFail(
            parser,
            "xmlns: prefix must be bound to " +
              XMLNS_NAMESPACE +
              "\n" +
              "Actual: " +
              parser.attribValue
          );
        } else {
          var tag = parser.tag;
          var parent = parser.tags[parser.tags.length - 1] || parser;
          if (tag.ns === parent.ns) {
            tag.ns = Object.create(parent.ns);
          }
          tag.ns[local] = parser.attribValue;
        }
      }

      // defer onattribute events until all attributes have been seen
      // so any new bindings can take effect. preserve attribute order
      // so deferred events can be emitted in document order
      parser.attribList.push([parser.attribName, parser.attribValue]);
    } else {
      // in non-xmlns mode, we can emit the event right away
      parser.tag.attributes[parser.attribName] = parser.attribValue;
      emitNode(parser, "onattribute", {
        name: parser.attribName,
        value: parser.attribValue,
      });
    }

    parser.attribName = parser.attribValue = "";
  }

  function openTag(parser, selfClosing) {
    if (parser.opt.xmlns) {
      // emit namespace binding events
      var tag = parser.tag;

      // add namespace info to tag
      var qn = qname(parser.tagName);
      tag.prefix = qn.prefix;
      tag.local = qn.local;
      tag.uri = tag.ns[qn.prefix] || "";

      if (tag.prefix && !tag.uri) {
        strictFail(
          parser,
          "Unbound namespace prefix: " + JSON.stringify(parser.tagName)
        );
        tag.uri = qn.prefix;
      }

      var parent = parser.tags[parser.tags.length - 1] || parser;
      if (tag.ns && parent.ns !== tag.ns) {
        Object.keys(tag.ns).forEach(function (p) {
          emitNode(parser, "onopennamespace", {
            prefix: p,
            uri: tag.ns[p],
          });
        });
      }

      // handle deferred onattribute events
      // Note: do not apply default ns to attributes:
      //   http://www.w3.org/TR/REC-xml-names/#defaulting
      for (var i = 0, l = parser.attribList.length; i < l; i++) {
        var nv = parser.attribList[i];
        var name = nv[0];
        var value = nv[1];
        var qualName = qname(name, true);
        var prefix = qualName.prefix;
        var local = qualName.local;
        var uri = prefix === "" ? "" : tag.ns[prefix] || "";
        var a = {
          name: name,
          value: value,
          prefix: prefix,
          local: local,
          uri: uri,
        };

        // if there's any attributes with an undefined namespace,
        // then fail on them now.
        if (prefix && prefix !== "xmlns" && !uri) {
          strictFail(
            parser,
            "Unbound namespace prefix: " + JSON.stringify(prefix)
          );
          a.uri = prefix;
        }
        parser.tag.attributes[name] = a;
        emitNode(parser, "onattribute", a);
      }
      parser.attribList.length = 0;
    }

    parser.tag.isSelfClosing = !!selfClosing;

    // process the tag
    parser.sawRoot = true;
    parser.tags.push(parser.tag);
    emitNode(parser, "onopentag", parser.tag);
    if (!selfClosing) {
      // special case for <script> in non-strict mode.
      if (!parser.noscript && parser.tagName.toLowerCase() === "script") {
        parser.state = S.SCRIPT;
      } else {
        parser.state = S.TEXT;
      }
      parser.tag = null;
      parser.tagName = "";
    }
    parser.attribName = parser.attribValue = "";
    parser.attribList.length = 0;
  }

  function closeTag(parser) {
    if (!parser.tagName) {
      strictFail(parser, "Weird empty close tag.");
      parser.textNode += "</>";
      parser.state = S.TEXT;
      return;
    }

    if (parser.script) {
      if (parser.tagName !== "script") {
        parser.script += "</" + parser.tagName + ">";
        parser.tagName = "";
        parser.state = S.SCRIPT;
        return;
      }
      emitNode(parser, "onscript", parser.script);
      parser.script = "";
    }

    // first make sure that the closing tag actually exists.
    // <a><b></c></b></a> will close everything, otherwise.
    var t = parser.tags.length;
    var tagName = parser.tagName;
    if (!parser.strict) {
      tagName = tagName[parser.looseCase]();
    }
    var closeTo = tagName;
    while (t--) {
      var close = parser.tags[t];
      if (close.name !== closeTo) {
        // fail the first time in strict mode
        strictFail(parser, "Unexpected close tag");
      } else {
        break;
      }
    }

    // didn't find it.  we already failed for strict, so just abort.
    if (t < 0) {
      strictFail(parser, "Unmatched closing tag: " + parser.tagName);
      parser.textNode += "</" + parser.tagName + ">";
      parser.state = S.TEXT;
      return;
    }
    parser.tagName = tagName;
    var s = parser.tags.length;
    while (s-- > t) {
      var tag = (parser.tag = parser.tags.pop());
      parser.tagName = parser.tag.name;
      emitNode(parser, "onclosetag", parser.tagName);

      var x = {};
      for (var i in tag.ns) {
        x[i] = tag.ns[i];
      }

      var parent = parser.tags[parser.tags.length - 1] || parser;
      if (parser.opt.xmlns && tag.ns !== parent.ns) {
        // remove namespace bindings introduced by tag
        Object.keys(tag.ns).forEach(function (p) {
          var n = tag.ns[p];
          emitNode(parser, "onclosenamespace", { prefix: p, uri: n });
        });
      }
    }
    if (t === 0) parser.closedRoot = true;
    parser.tagName = parser.attribValue = parser.attribName = "";
    parser.attribList.length = 0;
    parser.state = S.TEXT;
  }

  function parseEntity(parser) {
    var entity = parser.entity;
    var entityLC = entity.toLowerCase();
    var num;
    var numStr = "";

    if (parser.ENTITIES[entity]) {
      return parser.ENTITIES[entity];
    }
    if (parser.ENTITIES[entityLC]) {
      return parser.ENTITIES[entityLC];
    }
    entity = entityLC;
    if (entity.charAt(0) === "#") {
      if (entity.charAt(1) === "x") {
        entity = entity.slice(2);
        num = parseInt(entity, 16);
        numStr = num.toString(16);
      } else {
        entity = entity.slice(1);
        num = parseInt(entity, 10);
        numStr = num.toString(10);
      }
    }
    entity = entity.replace(/^0+/, "");
    if (isNaN(num) || numStr.toLowerCase() !== entity) {
      strictFail(parser, "Invalid character entity");
      return "&" + parser.entity + ";";
    }

    return String.fromCodePoint(num);
  }

  function beginWhiteSpace(parser, c) {
    if (c === "<") {
      parser.state = S.OPEN_WAKA;
      parser.startTagPosition = parser.position;
    } else if (!isWhitespace(c)) {
      // have to process this as a text node.
      // weird, but happens.
      strictFail(parser, "Non-whitespace before first tag.");
      parser.textNode = c;
      parser.state = S.TEXT;
    }
  }

  function charAt(chunk, i) {
    var result = "";
    if (i < chunk.length) {
      result = chunk.charAt(i);
    }
    return result;
  }

  function write(chunk) {
    var parser = this;
    if (this.error) {
      throw this.error;
    }
    if (parser.closed) {
      return error(
        parser,
        "Cannot write after close. Assign an onready handler."
      );
    }
    if (chunk === null) {
      return end(parser);
    }
    if (typeof chunk === "object") {
      chunk = chunk.toString();
    }
    var i = 0;
    var c = "";
    while (true) {
      c = charAt(chunk, i++);
      parser.c = c;

      if (!c) {
        break;
      }

      if (parser.trackPosition) {
        parser.position++;
        if (c === "\n") {
          parser.line++;
          parser.column = 0;
        } else {
          parser.column++;
        }
      }

      switch (parser.state) {
        case S.BEGIN:
          parser.state = S.BEGIN_WHITESPACE;
          if (c === "\uFEFF") {
            continue;
          }
          beginWhiteSpace(parser, c);
          continue;

        case S.BEGIN_WHITESPACE:
          beginWhiteSpace(parser, c);
          continue;

        case S.TEXT:
          if (parser.sawRoot && !parser.closedRoot) {
            var starti = i - 1;
            while (c && c !== "<" && c !== "&") {
              c = charAt(chunk, i++);
              if (c && parser.trackPosition) {
                parser.position++;
                if (c === "\n") {
                  parser.line++;
                  parser.column = 0;
                } else {
                  parser.column++;
                }
              }
            }
            parser.textNode += chunk.substring(starti, i - 1);
          }
          if (
            c === "<" &&
            !(parser.sawRoot && parser.closedRoot && !parser.strict)
          ) {
            parser.state = S.OPEN_WAKA;
            parser.startTagPosition = parser.position;
          } else {
            if (!isWhitespace(c) && (!parser.sawRoot || parser.closedRoot)) {
              strictFail(parser, "Text data outside of root node.");
            }
            if (c === "&") {
              parser.state = S.TEXT_ENTITY;
            } else {
              parser.textNode += c;
            }
          }
          continue;

        case S.SCRIPT:
          // only non-strict
          if (c === "<") {
            parser.state = S.SCRIPT_ENDING;
          } else {
            parser.script += c;
          }
          continue;

        case S.SCRIPT_ENDING:
          if (c === "/") {
            parser.state = S.CLOSE_TAG;
          } else {
            parser.script += "<" + c;
            parser.state = S.SCRIPT;
          }
          continue;

        case S.OPEN_WAKA:
          // either a /, ?, !, or text is coming next.
          if (c === "!") {
            parser.state = S.SGML_DECL;
            parser.sgmlDecl = "";
          } else if (isWhitespace(c)) {
            // wait for it...
          } else if (isMatch(nameStart, c)) {
            parser.state = S.OPEN_TAG;
            parser.tagName = c;
          } else if (c === "/") {
            parser.state = S.CLOSE_TAG;
            parser.tagName = "";
          } else if (c === "?") {
            parser.state = S.PROC_INST;
            parser.procInstName = parser.procInstBody = "";
          } else {
            strictFail(parser, "Unencoded <");
            // if there was some whitespace, then add that in.
            if (parser.startTagPosition + 1 < parser.position) {
              var pad = parser.position - parser.startTagPosition;
              c = new Array(pad).join(" ") + c;
            }
            parser.textNode += "<" + c;
            parser.state = S.TEXT;
          }
          continue;

        case S.SGML_DECL:
          if ((parser.sgmlDecl + c).toUpperCase() === CDATA) {
            emitNode(parser, "onopencdata");
            parser.state = S.CDATA;
            parser.sgmlDecl = "";
            parser.cdata = "";
          } else if (parser.sgmlDecl + c === "--") {
            parser.state = S.COMMENT;
            parser.comment = "";
            parser.sgmlDecl = "";
          } else if ((parser.sgmlDecl + c).toUpperCase() === DOCTYPE) {
            parser.state = S.DOCTYPE;
            if (parser.doctype || parser.sawRoot) {
              strictFail(parser, "Inappropriately located doctype declaration");
            }
            parser.doctype = "";
            parser.sgmlDecl = "";
          } else if (c === ">") {
            emitNode(parser, "onsgmldeclaration", parser.sgmlDecl);
            parser.sgmlDecl = "";
            parser.state = S.TEXT;
          } else if (isQuote(c)) {
            parser.state = S.SGML_DECL_QUOTED;
            parser.sgmlDecl += c;
          } else {
            parser.sgmlDecl += c;
          }
          continue;

        case S.SGML_DECL_QUOTED:
          if (c === parser.q) {
            parser.state = S.SGML_DECL;
            parser.q = "";
          }
          parser.sgmlDecl += c;
          continue;

        case S.DOCTYPE:
          if (c === ">") {
            parser.state = S.TEXT;
            emitNode(parser, "ondoctype", parser.doctype);
            parser.doctype = true; // just remember that we saw it.
          } else {
            parser.doctype += c;
            if (c === "[") {
              parser.state = S.DOCTYPE_DTD;
            } else if (isQuote(c)) {
              parser.state = S.DOCTYPE_QUOTED;
              parser.q = c;
            }
          }
          continue;

        case S.DOCTYPE_QUOTED:
          parser.doctype += c;
          if (c === parser.q) {
            parser.q = "";
            parser.state = S.DOCTYPE;
          }
          continue;

        case S.DOCTYPE_DTD:
          parser.doctype += c;
          if (c === "]") {
            parser.state = S.DOCTYPE;
          } else if (isQuote(c)) {
            parser.state = S.DOCTYPE_DTD_QUOTED;
            parser.q = c;
          }
          continue;

        case S.DOCTYPE_DTD_QUOTED:
          parser.doctype += c;
          if (c === parser.q) {
            parser.state = S.DOCTYPE_DTD;
            parser.q = "";
          }
          continue;

        case S.COMMENT:
          if (c === "-") {
            parser.state = S.COMMENT_ENDING;
          } else {
            parser.comment += c;
          }
          continue;

        case S.COMMENT_ENDING:
          if (c === "-") {
            parser.state = S.COMMENT_ENDED;
            parser.comment = textopts(parser.opt, parser.comment);
            if (parser.comment) {
              emitNode(parser, "oncomment", parser.comment);
            }
            parser.comment = "";
          } else {
            parser.comment += "-" + c;
            parser.state = S.COMMENT;
          }
          continue;

        case S.COMMENT_ENDED:
          if (c !== ">") {
            strictFail(parser, "Malformed comment");
            // allow <!-- blah -- bloo --> in non-strict mode,
            // which is a comment of " blah -- bloo "
            parser.comment += "--" + c;
            parser.state = S.COMMENT;
          } else {
            parser.state = S.TEXT;
          }
          continue;

        case S.CDATA:
          if (c === "]") {
            parser.state = S.CDATA_ENDING;
          } else {
            parser.cdata += c;
          }
          continue;

        case S.CDATA_ENDING:
          if (c === "]") {
            parser.state = S.CDATA_ENDING_2;
          } else {
            parser.cdata += "]" + c;
            parser.state = S.CDATA;
          }
          continue;

        case S.CDATA_ENDING_2:
          if (c === ">") {
            if (parser.cdata) {
              emitNode(parser, "oncdata", parser.cdata);
            }
            emitNode(parser, "onclosecdata");
            parser.cdata = "";
            parser.state = S.TEXT;
          } else if (c === "]") {
            parser.cdata += "]";
          } else {
            parser.cdata += "]]" + c;
            parser.state = S.CDATA;
          }
          continue;

        case S.PROC_INST:
          if (c === "?") {
            parser.state = S.PROC_INST_ENDING;
          } else if (isWhitespace(c)) {
            parser.state = S.PROC_INST_BODY;
          } else {
            parser.procInstName += c;
          }
          continue;

        case S.PROC_INST_BODY:
          if (!parser.procInstBody && isWhitespace(c)) {
            continue;
          } else if (c === "?") {
            parser.state = S.PROC_INST_ENDING;
          } else {
            parser.procInstBody += c;
          }
          continue;

        case S.PROC_INST_ENDING:
          if (c === ">") {
            emitNode(parser, "onprocessinginstruction", {
              name: parser.procInstName,
              body: parser.procInstBody,
            });
            parser.procInstName = parser.procInstBody = "";
            parser.state = S.TEXT;
          } else {
            parser.procInstBody += "?" + c;
            parser.state = S.PROC_INST_BODY;
          }
          continue;

        case S.OPEN_TAG:
          if (isMatch(nameBody, c)) {
            parser.tagName += c;
          } else {
            newTag(parser);
            if (c === ">") {
              openTag(parser);
            } else if (c === "/") {
              parser.state = S.OPEN_TAG_SLASH;
            } else {
              if (!isWhitespace(c)) {
                strictFail(parser, "Invalid character in tag name");
              }
              parser.state = S.ATTRIB;
            }
          }
          continue;

        case S.OPEN_TAG_SLASH:
          if (c === ">") {
            openTag(parser, true);
            closeTag(parser);
          } else {
            strictFail(
              parser,
              "Forward-slash in opening tag not followed by >"
            );
            parser.state = S.ATTRIB;
          }
          continue;

        case S.ATTRIB:
          // haven't read the attribute name yet.
          if (isWhitespace(c)) {
            continue;
          } else if (c === ">") {
            openTag(parser);
          } else if (c === "/") {
            parser.state = S.OPEN_TAG_SLASH;
          } else if (isMatch(nameStart, c)) {
            parser.attribName = c;
            parser.attribValue = "";
            parser.state = S.ATTRIB_NAME;
          } else {
            strictFail(parser, "Invalid attribute name");
          }
          continue;

        case S.ATTRIB_NAME:
          if (c === "=") {
            parser.state = S.ATTRIB_VALUE;
          } else if (c === ">") {
            strictFail(parser, "Attribute without value");
            parser.attribValue = parser.attribName;
            attrib(parser);
            openTag(parser);
          } else if (isWhitespace(c)) {
            parser.state = S.ATTRIB_NAME_SAW_WHITE;
          } else if (isMatch(nameBody, c)) {
            parser.attribName += c;
          } else {
            strictFail(parser, "Invalid attribute name");
          }
          continue;

        case S.ATTRIB_NAME_SAW_WHITE:
          if (c === "=") {
            parser.state = S.ATTRIB_VALUE;
          } else if (isWhitespace(c)) {
            continue;
          } else {
            strictFail(parser, "Attribute without value");
            parser.tag.attributes[parser.attribName] = "";
            parser.attribValue = "";
            emitNode(parser, "onattribute", {
              name: parser.attribName,
              value: "",
            });
            parser.attribName = "";
            if (c === ">") {
              openTag(parser);
            } else if (isMatch(nameStart, c)) {
              parser.attribName = c;
              parser.state = S.ATTRIB_NAME;
            } else {
              strictFail(parser, "Invalid attribute name");
              parser.state = S.ATTRIB;
            }
          }
          continue;

        case S.ATTRIB_VALUE:
          if (isWhitespace(c)) {
            continue;
          } else if (isQuote(c)) {
            parser.q = c;
            parser.state = S.ATTRIB_VALUE_QUOTED;
          } else {
            strictFail(parser, "Unquoted attribute value");
            parser.state = S.ATTRIB_VALUE_UNQUOTED;
            parser.attribValue = c;
          }
          continue;

        case S.ATTRIB_VALUE_QUOTED:
          if (c !== parser.q) {
            if (c === "&") {
              parser.state = S.ATTRIB_VALUE_ENTITY_Q;
            } else {
              parser.attribValue += c;
            }
            continue;
          }
          attrib(parser);
          parser.q = "";
          parser.state = S.ATTRIB_VALUE_CLOSED;
          continue;

        case S.ATTRIB_VALUE_CLOSED:
          if (isWhitespace(c)) {
            parser.state = S.ATTRIB;
          } else if (c === ">") {
            openTag(parser);
          } else if (c === "/") {
            parser.state = S.OPEN_TAG_SLASH;
          } else if (isMatch(nameStart, c)) {
            strictFail(parser, "No whitespace between attributes");
            parser.attribName = c;
            parser.attribValue = "";
            parser.state = S.ATTRIB_NAME;
          } else {
            strictFail(parser, "Invalid attribute name");
          }
          continue;

        case S.ATTRIB_VALUE_UNQUOTED:
          if (!isAttribEnd(c)) {
            if (c === "&") {
              parser.state = S.ATTRIB_VALUE_ENTITY_U;
            } else {
              parser.attribValue += c;
            }
            continue;
          }
          attrib(parser);
          if (c === ">") {
            openTag(parser);
          } else {
            parser.state = S.ATTRIB;
          }
          continue;

        case S.CLOSE_TAG:
          if (!parser.tagName) {
            if (isWhitespace(c)) {
              continue;
            } else if (notMatch(nameStart, c)) {
              if (parser.script) {
                parser.script += "</" + c;
                parser.state = S.SCRIPT;
              } else {
                strictFail(parser, "Invalid tagname in closing tag.");
              }
            } else {
              parser.tagName = c;
            }
          } else if (c === ">") {
            closeTag(parser);
          } else if (isMatch(nameBody, c)) {
            parser.tagName += c;
          } else if (parser.script) {
            parser.script += "</" + parser.tagName;
            parser.tagName = "";
            parser.state = S.SCRIPT;
          } else {
            if (!isWhitespace(c)) {
              strictFail(parser, "Invalid tagname in closing tag");
            }
            parser.state = S.CLOSE_TAG_SAW_WHITE;
          }
          continue;

        case S.CLOSE_TAG_SAW_WHITE:
          if (isWhitespace(c)) {
            continue;
          }
          if (c === ">") {
            closeTag(parser);
          } else {
            strictFail(parser, "Invalid characters in closing tag");
          }
          continue;

        case S.TEXT_ENTITY:
        case S.ATTRIB_VALUE_ENTITY_Q:
        case S.ATTRIB_VALUE_ENTITY_U:
          var returnState;
          var buffer;
          switch (parser.state) {
            case S.TEXT_ENTITY:
              returnState = S.TEXT;
              buffer = "textNode";
              break;

            case S.ATTRIB_VALUE_ENTITY_Q:
              returnState = S.ATTRIB_VALUE_QUOTED;
              buffer = "attribValue";
              break;

            case S.ATTRIB_VALUE_ENTITY_U:
              returnState = S.ATTRIB_VALUE_UNQUOTED;
              buffer = "attribValue";
              break;
          }

          if (c === ";") {
            if (parser.opt.unparsedEntities) {
              var parsedEntity = parseEntity(parser);
              parser.entity = "";
              parser.state = returnState;
              parser.write(parsedEntity);
            } else {
              parser[buffer] += parseEntity(parser);
              parser.entity = "";
              parser.state = returnState;
            }
          } else if (
            isMatch(parser.entity.length ? entityBody : entityStart, c)
          ) {
            parser.entity += c;
          } else {
            strictFail(parser, "Invalid character in entity name");
            parser[buffer] += "&" + parser.entity + c;
            parser.entity = "";
            parser.state = returnState;
          }

          continue;

        default: /* istanbul ignore next */ {
          throw new Error(parser, "Unknown state: " + parser.state);
        }
      }
    } // while

    if (parser.position >= parser.bufferCheckPosition) {
      checkBufferLength(parser);
    }
    return parser;
  }

  /*! http://mths.be/fromcodepoint v0.1.0 by @mathias */
  /* istanbul ignore next */
  if (!String.fromCodePoint) {
    (function () {
      var stringFromCharCode = String.fromCharCode;
      var floor = Math.floor;
      var fromCodePoint = function () {
        var MAX_SIZE = 0x4000;
        var codeUnits = [];
        var highSurrogate;
        var lowSurrogate;
        var index = -1;
        var length = arguments.length;
        if (!length) {
          return "";
        }
        var result = "";
        while (++index < length) {
          var codePoint = Number(arguments[index]);
          if (
            !isFinite(codePoint) || // `NaN`, `+Infinity`, or `-Infinity`
            codePoint < 0 || // not a valid Unicode code point
            codePoint > 0x10ffff || // not a valid Unicode code point
            floor(codePoint) !== codePoint // not an integer
          ) {
            throw RangeError("Invalid code point: " + codePoint);
          }
          if (codePoint <= 0xffff) {
            // BMP code point
            codeUnits.push(codePoint);
          } else {
            // Astral code point; split in surrogate halves
            // http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
            codePoint -= 0x10000;
            highSurrogate = (codePoint >> 10) + 0xd800;
            lowSurrogate = (codePoint % 0x400) + 0xdc00;
            codeUnits.push(highSurrogate, lowSurrogate);
          }
          if (index + 1 === length || codeUnits.length > MAX_SIZE) {
            result += stringFromCharCode.apply(null, codeUnits);
            codeUnits.length = 0;
          }
        }
        return result;
      };
      /* istanbul ignore next */
      if (Object.defineProperty) {
        Object.defineProperty(String, "fromCodePoint", {
          value: fromCodePoint,
          configurable: true,
          writable: true,
        });
      } else {
        String.fromCodePoint = fromCodePoint;
      }
    })();
  }
  return sax;
};

const sax = /** #__PURE__ */ initializeSax();

export { sax };