text: 
  /*!
   * Module dependencies.
   */
  
  var SchemaType = require('../schematype')
    , CastError = SchemaType.CastError
    , errorMessages = require('../error').messages
    , utils = require('../utils')
    , Document
  
  /**
   * String SchemaType constructor.
   *
   * @param {String} key
   * @param {Object} options
   * @inherits SchemaType
   * @api private
   */
  
  function SchemaString (key, options) {
    this.enumValues = [];
    this.regExp = null;
    SchemaType.call(this, key, options, 'String');
  };
  
  /*!
   * Inherits from SchemaType.
   */
  
  SchemaString.prototype.__proto__ = SchemaType.prototype;
  
  /**
   * Adds an enum validator
   *
   * ####Example:
   *
   *     var states = 'opening open closing closed'.split(' ')
   *     var s = new Schema({ state: { type: String, enum: states }})
   *     var M = db.model('M', s)
   *     var m = new M({ state: 'invalid' })
   *     m.save(function (err) {
   *       console.error(String(err)) // ValidationError: `invalid` is not a valid enum value for path `state`.
   *       m.state = 'open'
   *       m.save(callback) // success
   *     })
   *
   *     // or with custom error messages
   *     var enu = {
   *       values: 'opening open closing closed'.split(' '),
   *       message: 'enum validator failed for path `{PATH}` with value `{VALUE}`'
   *     }
   *     var s = new Schema({ state: { type: String, enum: enu })
   *     var M = db.model('M', s)
   *     var m = new M({ state: 'invalid' })
   *     m.save(function (err) {
   *       console.error(String(err)) // ValidationError: enum validator failed for path `state` with value `invalid`
   *       m.state = 'open'
   *       m.save(callback) // success
   *     })
   *
   * @param {String|Object} [args...] enumeration values
   * @return {SchemaType} this
   * @see Customized Error Messages #error_messages_MongooseError-messages
   * @api public
   */
  
  SchemaString.prototype.enum = function () {
    var len = arguments.length;
  
    if (this.enumValidator) {
      this.validators = this.validators.filter(function(v){
        return v[0] != this.enumValidator;
      }, this);
      this.enumValidator = false;
    }
  
    if (undefined === arguments[0] || false === arguments[0]) {
      return this;
    }
  
    var values;
    if (utils.isObject(arguments[0])) {
      values = arguments[0].values;
      errorMessage = arguments[0].message;
    } else {
      values = arguments;
      errorMessage = errorMessages.String.enum;
    }
  
    for (var i = 0; i < len; i++) {
      if (undefined !== values[i]) {
        this.enumValues.push(this.cast(values[i]));
      }
    }
  
    var vals = this.enumValues;
    this.enumValidator = function (v) {
      return undefined === v || ~vals.indexOf(v);
    };
    this.validators.push([this.enumValidator, errorMessage, 'enum']);
  
    return this;
  };
  
  /**
   * Adds a lowercase setter.
   *
   * ####Example:
   *
   *     var s = new Schema({ email: { type: String, lowercase: true }})
   *     var M = db.model('M', s);
   *     var m = new M({ email: 'SomeEmail@example.COM' });
   *     console.log(m.email) // someemail@example.com
   *
   * @api public
   * @return {SchemaType} this
   */
  
  SchemaString.prototype.lowercase = function () {
    return this.set(function (v, self) {
      if ('string' != typeof v) v = self.cast(v)
      if (v) return v.toLowerCase();
      return v;
    });
  };
  
  /**
   * Adds an uppercase setter.
   *
   * ####Example:
   *
   *     var s = new Schema({ caps: { type: String, uppercase: true }})
   *     var M = db.model('M', s);
   *     var m = new M({ caps: 'an example' });
   *     console.log(m.caps) // AN EXAMPLE
   *
   * @api public
   * @return {SchemaType} this
   */
  
  SchemaString.prototype.uppercase = function () {
    return this.set(function (v, self) {
      if ('string' != typeof v) v = self.cast(v)
      if (v) return v.toUpperCase();
      return v;
    });
  };
  
  /**
   * Adds a trim setter.
   *
   * The string value will be trimmed when set.
   *
   * ####Example:
   *
   *     var s = new Schema({ name: { type: String, trim: true }})
   *     var M = db.model('M', s)
   *     var string = ' some name '
   *     console.log(string.length) // 11
   *     var m = new M({ name: string })
   *     console.log(m.name.length) // 9
   *
   * @api public
   * @return {SchemaType} this
   */
  
  SchemaString.prototype.trim = function () {
    return this.set(function (v, self) {
      if ('string' != typeof v) v = self.cast(v)
      if (v) return v.trim();
      return v;
    });
  };
  
  /**
   * Sets a regexp validator.
   *
   * Any value that does not pass `regExp`.test(val) will fail validation.
   *
   * ####Example:
   *
   *     var s = new Schema({ name: { type: String, match: /^a/ }})
   *     var M = db.model('M', s)
   *     var m = new M({ name: 'I am invalid' })
   *     m.validate(function (err) {
   *       console.error(String(err)) // "ValidationError: Path `name` is invalid (I am invalid)."
   *       m.name = 'apples'
   *       m.validate(function (err) {
   *         assert.ok(err) // success
   *       })
   *     })
   *
   *     // using a custom error message
   *     var match = [ /\.html$/, "That file doesn't end in .html ({VALUE})" ];
   *     var s = new Schema({ file: { type: String, match: match }})
   *     var M = db.model('M', s);
   *     var m = new M({ file: 'invalid' });
   *     m.validate(function (err) {
   *       console.log(String(err)) // "ValidationError: That file doesn't end in .html (invalid)"
   *     })
   *
   * Empty strings, `undefined`, and `null` values always pass the match validator. If you require these values, enable the `required` validator also.
   *
   *     var s = new Schema({ name: { type: String, match: /^a/, required: true }})
   *
   * @param {RegExp} regExp regular expression to test against
   * @param {String} [message] optional custom error message
   * @return {SchemaType} this
   * @see Customized Error Messages #error_messages_MongooseError-messages
   * @api public
   */
  
  SchemaString.prototype.match = function match (regExp, message) {
    // yes, we allow multiple match validators
  
    var msg = message || errorMessages.String.match;
  
    function matchValidator (v){
      return null != v && '' !== v
        ? regExp.test(v)
        : true
    }
  
    this.validators.push([matchValidator, msg, 'regexp']);
    return this;
  };
  
  /**
   * Check required
   *
   * @param {String|null|undefined} value
   * @api private
   */
  
  SchemaString.prototype.checkRequired = function checkRequired (value, doc) {
    if (SchemaType._isRef(this, value, doc, true)) {
      return null != value;
    } else {
      return (value instanceof String || typeof value == 'string') && value.length;
    }
  };
  
  /**
   * Casts to String
   *
   * @api private
   */
  
  SchemaString.prototype.cast = function (value, doc, init) {
    if (SchemaType._isRef(this, value, doc, init)) {
      // wait! we may need to cast this to a document
  
      if (null == value) {
        return value;
      }
  
      // lazy load
      Document || (Document = require('./../document'));
  
      if (value instanceof Document) {
        value.$__.wasPopulated = true;
        return value;
      }
  
      // setting a populated path
      if ('string' == typeof value) {
        return value;
      } else if (Buffer.isBuffer(value) || !utils.isObject(value)) {
        throw new CastError('string', value, this.path);
      }
  
      // Handle the case where user directly sets a populated
      // path to a plain object; cast to the Model used in
      // the population query.
      var path = doc.$__fullPath(this.path);
      var owner = doc.ownerDocument ? doc.ownerDocument() : doc;
      var pop = owner.populated(path, true);
      var ret = new pop.options.model(value);
      ret.$__.wasPopulated = true;
      return ret;
    }
  
    if (value === null) {
      return value;
    }
  
    if ('undefined' !== typeof value) {
      // handle documents being passed
      if (value._id && 'string' == typeof value._id) {
        return value._id;
      }
      if (value.toString) {
        return value.toString();
      }
    }
  
  
    throw new CastError('string', value, this.path);
  };
  
  /*!
   * ignore
   */
  
  function handleSingle (val) {
    return this.castForQuery(val);
  }
  
  function handleArray (val) {
    var self = this;
    return val.map(function (m) {
      return self.castForQuery(m);
    });
  }
  
  SchemaString.prototype.$conditionalHandlers = {
      '$ne' : handleSingle
    , '$in' : handleArray
    , '$nin': handleArray
    , '$gt' : handleSingle
    , '$lt' : handleSingle
    , '$gte': handleSingle
    , '$lte': handleSingle
    , '$all': handleArray
    , '$regex': handleSingle
    , '$options': handleSingle
  };
  
  /**
   * Casts contents for queries.
   *
   * @param {String} $conditional
   * @param {any} [val]
   * @api private
   */
  
  SchemaString.prototype.castForQuery = function ($conditional, val) {
    var handler;
    if (arguments.length === 2) {
      handler = this.$conditionalHandlers[$conditional];
      if (!handler)
        throw new Error("Can't use " + $conditional + " with String.");
      return handler.call(this, val);
    } else {
      val = $conditional;
      if (val instanceof RegExp) return val;
      return this.cast(val);
    }
  };
  
  /*!
   * Module exports.
   */
  
  module.exports = SchemaString;
  