text: 'use strict'
  
  var assert = require('assert')
  var decodeEntity = require('parse-entities/decode-entity.js')
  var asciiAlphanumeric = require('../character/ascii-alphanumeric.js')
  var asciiDigit = require('../character/ascii-digit.js')
  var asciiHexDigit = require('../character/ascii-hex-digit.js')
  var codes = require('../character/codes.js')
  var constants = require('../constant/constants.js')
  var types = require('../constant/types.js')
  
  function _interopDefaultLegacy(e) {
    return e && typeof e === 'object' && 'default' in e ? e : {default: e}
  }
  
  var assert__default = /*#__PURE__*/ _interopDefaultLegacy(assert)
  var decodeEntity__default = /*#__PURE__*/ _interopDefaultLegacy(decodeEntity)
  
  var characterReference = {
    name: 'characterReference',
    tokenize: tokenizeCharacterReference
  }
  
  function tokenizeCharacterReference(effects, ok, nok) {
    var self = this
    var size = 0
    var max
    var test
  
    return start
  
    function start(code) {
      assert__default['default'](code === codes.ampersand, 'expected `&`')
      effects.enter(types.characterReference)
      effects.enter(types.characterReferenceMarker)
      effects.consume(code)
      effects.exit(types.characterReferenceMarker)
      return open
    }
  
    function open(code) {
      if (code === codes.numberSign) {
        effects.enter(types.characterReferenceMarkerNumeric)
        effects.consume(code)
        effects.exit(types.characterReferenceMarkerNumeric)
        return numeric
      }
  
      effects.enter(types.characterReferenceValue)
      max = constants.characterReferenceNamedSizeMax
      test = asciiAlphanumeric
      return value(code)
    }
  
    function numeric(code) {
      if (code === codes.uppercaseX || code === codes.lowercaseX) {
        effects.enter(types.characterReferenceMarkerHexadecimal)
        effects.consume(code)
        effects.exit(types.characterReferenceMarkerHexadecimal)
        effects.enter(types.characterReferenceValue)
        max = constants.characterReferenceHexadecimalSizeMax
        test = asciiHexDigit
        return value
      }
  
      effects.enter(types.characterReferenceValue)
      max = constants.characterReferenceDecimalSizeMax
      test = asciiDigit
      return value(code)
    }
  
    function value(code) {
      var token
  
      if (code === codes.semicolon && size) {
        token = effects.exit(types.characterReferenceValue)
  
        if (
          test === asciiAlphanumeric &&
          !decodeEntity__default['default'](self.sliceSerialize(token))
        ) {
          return nok(code)
        }
  
        effects.enter(types.characterReferenceMarker)
        effects.consume(code)
        effects.exit(types.characterReferenceMarker)
        effects.exit(types.characterReference)
        return ok
      }
  
      if (test(code) && size++ < max) {
        effects.consume(code)
        return value
      }
  
      return nok(code)
    }
  }
  
  module.exports = characterReference
  