'use strict';

////////////////////////////////////////////////////////////////////////////////
/// @brief Check if something is something
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2010-2012 triagens GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler, Lucas Dohmen
/// @author Copyright 2011-2012, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

// Check if a value is not undefined or null
function existy (x) {
  return x !== null && x !== undefined;
}

// Check if a value is undefined or null
function notExisty (x) {
  return !existy(x);
}

// Check if a value is existy and not false
function truthy (x) {
  return (x !== false) && existy(x);
}

// Check if a value is not truthy
function falsy (x) {
  return !truthy(x);
}

// is.object, is.noObject, is.array, is.noArray...
[
  'Object',
  'Array',
  'Boolean',
  'Date',
  'Function',
  'Number',
  'String',
  'RegExp'
].forEach(function(type) {
  exports[type.toLowerCase()] = function (obj) {
    return Object.prototype.toString.call(obj) === '[object '+type+']';
  };

  exports["no" + type] = function (obj) {
    return Object.prototype.toString.call(obj) !== '[object '+type+']';
  };
});

exports.existy = existy;
exports.notExisty = notExisty;
exports.truthy = truthy;
exports.falsy = falsy;