homework/js/Project/node_modules/react-router/umd/react-router.js

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('react')) :
  typeof define === 'function' && define.amd ? define(['exports', 'react'], factory) :
  (global = global || self, factory(global.ReactRouter = {}, global.React));
}(this, function (exports, React) { 'use strict';

  var React__default = 'default' in React ? React['default'] : React;

  function _setPrototypeOf(o, p) {
    _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) {
      o.__proto__ = p;
      return o;
    };

    return _setPrototypeOf(o, p);
  }

  function _inheritsLoose(subClass, superClass) {
    subClass.prototype = Object.create(superClass.prototype);
    subClass.prototype.constructor = subClass;
    _setPrototypeOf(subClass, superClass);
  }

  function unwrapExports (x) {
  	return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;
  }

  function createCommonjsModule(fn, module) {
  	return module = { exports: {} }, fn(module, module.exports), module.exports;
  }

  var reactIs_production_min = createCommonjsModule(function (module, exports) {
  Object.defineProperty(exports,"__esModule",{value:!0});
  var b="function"===typeof Symbol&&Symbol.for,c=b?Symbol.for("react.element"):60103,d=b?Symbol.for("react.portal"):60106,e=b?Symbol.for("react.fragment"):60107,f=b?Symbol.for("react.strict_mode"):60108,g=b?Symbol.for("react.profiler"):60114,h=b?Symbol.for("react.provider"):60109,k=b?Symbol.for("react.context"):60110,l=b?Symbol.for("react.async_mode"):60111,m=b?Symbol.for("react.concurrent_mode"):60111,n=b?Symbol.for("react.forward_ref"):60112,p=b?Symbol.for("react.suspense"):60113,q=b?Symbol.for("react.suspense_list"):
  60120,r=b?Symbol.for("react.memo"):60115,t=b?Symbol.for("react.lazy"):60116,v=b?Symbol.for("react.fundamental"):60117,w=b?Symbol.for("react.responder"):60118;function x(a){if("object"===typeof a&&null!==a){var u=a.$$typeof;switch(u){case c:switch(a=a.type,a){case l:case m:case e:case g:case f:case p:return a;default:switch(a=a&&a.$$typeof,a){case k:case n:case h:return a;default:return u}}case t:case r:case d:return u}}}function y(a){return x(a)===m}exports.typeOf=x;exports.AsyncMode=l;
  exports.ConcurrentMode=m;exports.ContextConsumer=k;exports.ContextProvider=h;exports.Element=c;exports.ForwardRef=n;exports.Fragment=e;exports.Lazy=t;exports.Memo=r;exports.Portal=d;exports.Profiler=g;exports.StrictMode=f;exports.Suspense=p;
  exports.isValidElementType=function(a){return "string"===typeof a||"function"===typeof a||a===e||a===m||a===g||a===f||a===p||a===q||"object"===typeof a&&null!==a&&(a.$$typeof===t||a.$$typeof===r||a.$$typeof===h||a.$$typeof===k||a.$$typeof===n||a.$$typeof===v||a.$$typeof===w)};exports.isAsyncMode=function(a){return y(a)||x(a)===l};exports.isConcurrentMode=y;exports.isContextConsumer=function(a){return x(a)===k};exports.isContextProvider=function(a){return x(a)===h};
  exports.isElement=function(a){return "object"===typeof a&&null!==a&&a.$$typeof===c};exports.isForwardRef=function(a){return x(a)===n};exports.isFragment=function(a){return x(a)===e};exports.isLazy=function(a){return x(a)===t};exports.isMemo=function(a){return x(a)===r};exports.isPortal=function(a){return x(a)===d};exports.isProfiler=function(a){return x(a)===g};exports.isStrictMode=function(a){return x(a)===f};exports.isSuspense=function(a){return x(a)===p};
  });

  unwrapExports(reactIs_production_min);
  var reactIs_production_min_1 = reactIs_production_min.typeOf;
  var reactIs_production_min_2 = reactIs_production_min.AsyncMode;
  var reactIs_production_min_3 = reactIs_production_min.ConcurrentMode;
  var reactIs_production_min_4 = reactIs_production_min.ContextConsumer;
  var reactIs_production_min_5 = reactIs_production_min.ContextProvider;
  var reactIs_production_min_6 = reactIs_production_min.Element;
  var reactIs_production_min_7 = reactIs_production_min.ForwardRef;
  var reactIs_production_min_8 = reactIs_production_min.Fragment;
  var reactIs_production_min_9 = reactIs_production_min.Lazy;
  var reactIs_production_min_10 = reactIs_production_min.Memo;
  var reactIs_production_min_11 = reactIs_production_min.Portal;
  var reactIs_production_min_12 = reactIs_production_min.Profiler;
  var reactIs_production_min_13 = reactIs_production_min.StrictMode;
  var reactIs_production_min_14 = reactIs_production_min.Suspense;
  var reactIs_production_min_15 = reactIs_production_min.isValidElementType;
  var reactIs_production_min_16 = reactIs_production_min.isAsyncMode;
  var reactIs_production_min_17 = reactIs_production_min.isConcurrentMode;
  var reactIs_production_min_18 = reactIs_production_min.isContextConsumer;
  var reactIs_production_min_19 = reactIs_production_min.isContextProvider;
  var reactIs_production_min_20 = reactIs_production_min.isElement;
  var reactIs_production_min_21 = reactIs_production_min.isForwardRef;
  var reactIs_production_min_22 = reactIs_production_min.isFragment;
  var reactIs_production_min_23 = reactIs_production_min.isLazy;
  var reactIs_production_min_24 = reactIs_production_min.isMemo;
  var reactIs_production_min_25 = reactIs_production_min.isPortal;
  var reactIs_production_min_26 = reactIs_production_min.isProfiler;
  var reactIs_production_min_27 = reactIs_production_min.isStrictMode;
  var reactIs_production_min_28 = reactIs_production_min.isSuspense;

  var reactIs_development = createCommonjsModule(function (module, exports) {



  {
    (function() {

  Object.defineProperty(exports, '__esModule', { value: true });

  // The Symbol used to tag the ReactElement-like types. If there is no native Symbol
  // nor polyfill, then a plain number is used for performance.
  var hasSymbol = typeof Symbol === 'function' && Symbol.for;

  var REACT_ELEMENT_TYPE = hasSymbol ? Symbol.for('react.element') : 0xeac7;
  var REACT_PORTAL_TYPE = hasSymbol ? Symbol.for('react.portal') : 0xeaca;
  var REACT_FRAGMENT_TYPE = hasSymbol ? Symbol.for('react.fragment') : 0xeacb;
  var REACT_STRICT_MODE_TYPE = hasSymbol ? Symbol.for('react.strict_mode') : 0xeacc;
  var REACT_PROFILER_TYPE = hasSymbol ? Symbol.for('react.profiler') : 0xead2;
  var REACT_PROVIDER_TYPE = hasSymbol ? Symbol.for('react.provider') : 0xeacd;
  var REACT_CONTEXT_TYPE = hasSymbol ? Symbol.for('react.context') : 0xeace;
  // TODO: We don't use AsyncMode or ConcurrentMode anymore. They were temporary
  // (unstable) APIs that have been removed. Can we remove the symbols?
  var REACT_ASYNC_MODE_TYPE = hasSymbol ? Symbol.for('react.async_mode') : 0xeacf;
  var REACT_CONCURRENT_MODE_TYPE = hasSymbol ? Symbol.for('react.concurrent_mode') : 0xeacf;
  var REACT_FORWARD_REF_TYPE = hasSymbol ? Symbol.for('react.forward_ref') : 0xead0;
  var REACT_SUSPENSE_TYPE = hasSymbol ? Symbol.for('react.suspense') : 0xead1;
  var REACT_SUSPENSE_LIST_TYPE = hasSymbol ? Symbol.for('react.suspense_list') : 0xead8;
  var REACT_MEMO_TYPE = hasSymbol ? Symbol.for('react.memo') : 0xead3;
  var REACT_LAZY_TYPE = hasSymbol ? Symbol.for('react.lazy') : 0xead4;
  var REACT_FUNDAMENTAL_TYPE = hasSymbol ? Symbol.for('react.fundamental') : 0xead5;
  var REACT_RESPONDER_TYPE = hasSymbol ? Symbol.for('react.responder') : 0xead6;

  function isValidElementType(type) {
    return typeof type === 'string' || typeof type === 'function' ||
    // Note: its typeof might be other than 'symbol' or 'number' if it's a polyfill.
    type === REACT_FRAGMENT_TYPE || type === REACT_CONCURRENT_MODE_TYPE || type === REACT_PROFILER_TYPE || type === REACT_STRICT_MODE_TYPE || type === REACT_SUSPENSE_TYPE || type === REACT_SUSPENSE_LIST_TYPE || typeof type === 'object' && type !== null && (type.$$typeof === REACT_LAZY_TYPE || type.$$typeof === REACT_MEMO_TYPE || type.$$typeof === REACT_PROVIDER_TYPE || type.$$typeof === REACT_CONTEXT_TYPE || type.$$typeof === REACT_FORWARD_REF_TYPE || type.$$typeof === REACT_FUNDAMENTAL_TYPE || type.$$typeof === REACT_RESPONDER_TYPE);
  }

  /**
   * Forked from fbjs/warning:
   * https://github.com/facebook/fbjs/blob/e66ba20ad5be433eb54423f2b097d829324d9de6/packages/fbjs/src/__forks__/warning.js
   *
   * Only change is we use console.warn instead of console.error,
   * and do nothing when 'console' is not supported.
   * This really simplifies the code.
   * ---
   * Similar to invariant but only logs a warning if the condition is not met.
   * This can be used to log issues in development environments in critical
   * paths. Removing the logging code for production environments will keep the
   * same logic and follow the same code paths.
   */

  var lowPriorityWarning = function () {};

  {
    var printWarning = function (format) {
      for (var _len = arguments.length, args = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
        args[_key - 1] = arguments[_key];
      }

      var argIndex = 0;
      var message = 'Warning: ' + format.replace(/%s/g, function () {
        return args[argIndex++];
      });
      if (typeof console !== 'undefined') {
        console.warn(message);
      }
      try {
        // --- Welcome to debugging React ---
        // This error was thrown as a convenience so that you can use this stack
        // to find the callsite that caused this warning to fire.
        throw new Error(message);
      } catch (x) {}
    };

    lowPriorityWarning = function (condition, format) {
      if (format === undefined) {
        throw new Error('`lowPriorityWarning(condition, format, ...args)` requires a warning ' + 'message argument');
      }
      if (!condition) {
        for (var _len2 = arguments.length, args = Array(_len2 > 2 ? _len2 - 2 : 0), _key2 = 2; _key2 < _len2; _key2++) {
          args[_key2 - 2] = arguments[_key2];
        }

        printWarning.apply(undefined, [format].concat(args));
      }
    };
  }

  var lowPriorityWarning$1 = lowPriorityWarning;

  function typeOf(object) {
    if (typeof object === 'object' && object !== null) {
      var $$typeof = object.$$typeof;
      switch ($$typeof) {
        case REACT_ELEMENT_TYPE:
          var type = object.type;

          switch (type) {
            case REACT_ASYNC_MODE_TYPE:
            case REACT_CONCURRENT_MODE_TYPE:
            case REACT_FRAGMENT_TYPE:
            case REACT_PROFILER_TYPE:
            case REACT_STRICT_MODE_TYPE:
            case REACT_SUSPENSE_TYPE:
              return type;
            default:
              var $$typeofType = type && type.$$typeof;

              switch ($$typeofType) {
                case REACT_CONTEXT_TYPE:
                case REACT_FORWARD_REF_TYPE:
                case REACT_PROVIDER_TYPE:
                  return $$typeofType;
                default:
                  return $$typeof;
              }
          }
        case REACT_LAZY_TYPE:
        case REACT_MEMO_TYPE:
        case REACT_PORTAL_TYPE:
          return $$typeof;
      }
    }

    return undefined;
  }

  // AsyncMode is deprecated along with isAsyncMode
  var AsyncMode = REACT_ASYNC_MODE_TYPE;
  var ConcurrentMode = REACT_CONCURRENT_MODE_TYPE;
  var ContextConsumer = REACT_CONTEXT_TYPE;
  var ContextProvider = REACT_PROVIDER_TYPE;
  var Element = REACT_ELEMENT_TYPE;
  var ForwardRef = REACT_FORWARD_REF_TYPE;
  var Fragment = REACT_FRAGMENT_TYPE;
  var Lazy = REACT_LAZY_TYPE;
  var Memo = REACT_MEMO_TYPE;
  var Portal = REACT_PORTAL_TYPE;
  var Profiler = REACT_PROFILER_TYPE;
  var StrictMode = REACT_STRICT_MODE_TYPE;
  var Suspense = REACT_SUSPENSE_TYPE;

  var hasWarnedAboutDeprecatedIsAsyncMode = false;

  // AsyncMode should be deprecated
  function isAsyncMode(object) {
    {
      if (!hasWarnedAboutDeprecatedIsAsyncMode) {
        hasWarnedAboutDeprecatedIsAsyncMode = true;
        lowPriorityWarning$1(false, 'The ReactIs.isAsyncMode() alias has been deprecated, ' + 'and will be removed in React 17+. Update your code to use ' + 'ReactIs.isConcurrentMode() instead. It has the exact same API.');
      }
    }
    return isConcurrentMode(object) || typeOf(object) === REACT_ASYNC_MODE_TYPE;
  }
  function isConcurrentMode(object) {
    return typeOf(object) === REACT_CONCURRENT_MODE_TYPE;
  }
  function isContextConsumer(object) {
    return typeOf(object) === REACT_CONTEXT_TYPE;
  }
  function isContextProvider(object) {
    return typeOf(object) === REACT_PROVIDER_TYPE;
  }
  function isElement(object) {
    return typeof object === 'object' && object !== null && object.$$typeof === REACT_ELEMENT_TYPE;
  }
  function isForwardRef(object) {
    return typeOf(object) === REACT_FORWARD_REF_TYPE;
  }
  function isFragment(object) {
    return typeOf(object) === REACT_FRAGMENT_TYPE;
  }
  function isLazy(object) {
    return typeOf(object) === REACT_LAZY_TYPE;
  }
  function isMemo(object) {
    return typeOf(object) === REACT_MEMO_TYPE;
  }
  function isPortal(object) {
    return typeOf(object) === REACT_PORTAL_TYPE;
  }
  function isProfiler(object) {
    return typeOf(object) === REACT_PROFILER_TYPE;
  }
  function isStrictMode(object) {
    return typeOf(object) === REACT_STRICT_MODE_TYPE;
  }
  function isSuspense(object) {
    return typeOf(object) === REACT_SUSPENSE_TYPE;
  }

  exports.typeOf = typeOf;
  exports.AsyncMode = AsyncMode;
  exports.ConcurrentMode = ConcurrentMode;
  exports.ContextConsumer = ContextConsumer;
  exports.ContextProvider = ContextProvider;
  exports.Element = Element;
  exports.ForwardRef = ForwardRef;
  exports.Fragment = Fragment;
  exports.Lazy = Lazy;
  exports.Memo = Memo;
  exports.Portal = Portal;
  exports.Profiler = Profiler;
  exports.StrictMode = StrictMode;
  exports.Suspense = Suspense;
  exports.isValidElementType = isValidElementType;
  exports.isAsyncMode = isAsyncMode;
  exports.isConcurrentMode = isConcurrentMode;
  exports.isContextConsumer = isContextConsumer;
  exports.isContextProvider = isContextProvider;
  exports.isElement = isElement;
  exports.isForwardRef = isForwardRef;
  exports.isFragment = isFragment;
  exports.isLazy = isLazy;
  exports.isMemo = isMemo;
  exports.isPortal = isPortal;
  exports.isProfiler = isProfiler;
  exports.isStrictMode = isStrictMode;
  exports.isSuspense = isSuspense;
    })();
  }
  });

  unwrapExports(reactIs_development);
  var reactIs_development_1 = reactIs_development.typeOf;
  var reactIs_development_2 = reactIs_development.AsyncMode;
  var reactIs_development_3 = reactIs_development.ConcurrentMode;
  var reactIs_development_4 = reactIs_development.ContextConsumer;
  var reactIs_development_5 = reactIs_development.ContextProvider;
  var reactIs_development_6 = reactIs_development.Element;
  var reactIs_development_7 = reactIs_development.ForwardRef;
  var reactIs_development_8 = reactIs_development.Fragment;
  var reactIs_development_9 = reactIs_development.Lazy;
  var reactIs_development_10 = reactIs_development.Memo;
  var reactIs_development_11 = reactIs_development.Portal;
  var reactIs_development_12 = reactIs_development.Profiler;
  var reactIs_development_13 = reactIs_development.StrictMode;
  var reactIs_development_14 = reactIs_development.Suspense;
  var reactIs_development_15 = reactIs_development.isValidElementType;
  var reactIs_development_16 = reactIs_development.isAsyncMode;
  var reactIs_development_17 = reactIs_development.isConcurrentMode;
  var reactIs_development_18 = reactIs_development.isContextConsumer;
  var reactIs_development_19 = reactIs_development.isContextProvider;
  var reactIs_development_20 = reactIs_development.isElement;
  var reactIs_development_21 = reactIs_development.isForwardRef;
  var reactIs_development_22 = reactIs_development.isFragment;
  var reactIs_development_23 = reactIs_development.isLazy;
  var reactIs_development_24 = reactIs_development.isMemo;
  var reactIs_development_25 = reactIs_development.isPortal;
  var reactIs_development_26 = reactIs_development.isProfiler;
  var reactIs_development_27 = reactIs_development.isStrictMode;
  var reactIs_development_28 = reactIs_development.isSuspense;

  var reactIs = createCommonjsModule(function (module) {

  {
    module.exports = reactIs_development;
  }
  });
  var reactIs_1 = reactIs.isValidElementType;

  /*
  object-assign
  (c) Sindre Sorhus
  @license MIT
  */
  /* eslint-disable no-unused-vars */
  var getOwnPropertySymbols = Object.getOwnPropertySymbols;
  var hasOwnProperty = Object.prototype.hasOwnProperty;
  var propIsEnumerable = Object.prototype.propertyIsEnumerable;

  function toObject(val) {
  	if (val === null || val === undefined) {
  		throw new TypeError('Object.assign cannot be called with null or undefined');
  	}

  	return Object(val);
  }

  function shouldUseNative() {
  	try {
  		if (!Object.assign) {
  			return false;
  		}

  		// Detect buggy property enumeration order in older V8 versions.

  		// https://bugs.chromium.org/p/v8/issues/detail?id=4118
  		var test1 = new String('abc');  // eslint-disable-line no-new-wrappers
  		test1[5] = 'de';
  		if (Object.getOwnPropertyNames(test1)[0] === '5') {
  			return false;
  		}

  		// https://bugs.chromium.org/p/v8/issues/detail?id=3056
  		var test2 = {};
  		for (var i = 0; i < 10; i++) {
  			test2['_' + String.fromCharCode(i)] = i;
  		}
  		var order2 = Object.getOwnPropertyNames(test2).map(function (n) {
  			return test2[n];
  		});
  		if (order2.join('') !== '0123456789') {
  			return false;
  		}

  		// https://bugs.chromium.org/p/v8/issues/detail?id=3056
  		var test3 = {};
  		'abcdefghijklmnopqrst'.split('').forEach(function (letter) {
  			test3[letter] = letter;
  		});
  		if (Object.keys(Object.assign({}, test3)).join('') !==
  				'abcdefghijklmnopqrst') {
  			return false;
  		}

  		return true;
  	} catch (err) {
  		// We don't expect any of the above to throw, but better to be safe.
  		return false;
  	}
  }

  var objectAssign = shouldUseNative() ? Object.assign : function (target, source) {
  	var from;
  	var to = toObject(target);
  	var symbols;

  	for (var s = 1; s < arguments.length; s++) {
  		from = Object(arguments[s]);

  		for (var key in from) {
  			if (hasOwnProperty.call(from, key)) {
  				to[key] = from[key];
  			}
  		}

  		if (getOwnPropertySymbols) {
  			symbols = getOwnPropertySymbols(from);
  			for (var i = 0; i < symbols.length; i++) {
  				if (propIsEnumerable.call(from, symbols[i])) {
  					to[symbols[i]] = from[symbols[i]];
  				}
  			}
  		}
  	}

  	return to;
  };

  /**
   * Copyright (c) 2013-present, Facebook, Inc.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   */

  var ReactPropTypesSecret = 'SECRET_DO_NOT_PASS_THIS_OR_YOU_WILL_BE_FIRED';

  var ReactPropTypesSecret_1 = ReactPropTypesSecret;

  var printWarning = function() {};

  {
    var ReactPropTypesSecret$1 = ReactPropTypesSecret_1;
    var loggedTypeFailures = {};
    var has = Function.call.bind(Object.prototype.hasOwnProperty);

    printWarning = function(text) {
      var message = 'Warning: ' + text;
      if (typeof console !== 'undefined') {
        console.error(message);
      }
      try {
        // --- Welcome to debugging React ---
        // This error was thrown as a convenience so that you can use this stack
        // to find the callsite that caused this warning to fire.
        throw new Error(message);
      } catch (x) {}
    };
  }

  /**
   * Assert that the values match with the type specs.
   * Error messages are memorized and will only be shown once.
   *
   * @param {object} typeSpecs Map of name to a ReactPropType
   * @param {object} values Runtime values that need to be type-checked
   * @param {string} location e.g. "prop", "context", "child context"
   * @param {string} componentName Name of the component for error messages.
   * @param {?Function} getStack Returns the component stack.
   * @private
   */
  function checkPropTypes(typeSpecs, values, location, componentName, getStack) {
    {
      for (var typeSpecName in typeSpecs) {
        if (has(typeSpecs, typeSpecName)) {
          var error;
          // Prop type validation may throw. In case they do, we don't want to
          // fail the render phase where it didn't fail before. So we log it.
          // After these have been cleaned up, we'll let them throw.
          try {
            // This is intentionally an invariant that gets caught. It's the same
            // behavior as without this statement except with a better message.
            if (typeof typeSpecs[typeSpecName] !== 'function') {
              var err = Error(
                (componentName || 'React class') + ': ' + location + ' type `' + typeSpecName + '` is invalid; ' +
                'it must be a function, usually from the `prop-types` package, but received `' + typeof typeSpecs[typeSpecName] + '`.'
              );
              err.name = 'Invariant Violation';
              throw err;
            }
            error = typeSpecs[typeSpecName](values, typeSpecName, componentName, location, null, ReactPropTypesSecret$1);
          } catch (ex) {
            error = ex;
          }
          if (error && !(error instanceof Error)) {
            printWarning(
              (componentName || 'React class') + ': type specification of ' +
              location + ' `' + typeSpecName + '` is invalid; the type checker ' +
              'function must return `null` or an `Error` but returned a ' + typeof error + '. ' +
              'You may have forgotten to pass an argument to the type checker ' +
              'creator (arrayOf, instanceOf, objectOf, oneOf, oneOfType, and ' +
              'shape all require an argument).'
            );
          }
          if (error instanceof Error && !(error.message in loggedTypeFailures)) {
            // Only monitor this failure once because there tends to be a lot of the
            // same error.
            loggedTypeFailures[error.message] = true;

            var stack = getStack ? getStack() : '';

            printWarning(
              'Failed ' + location + ' type: ' + error.message + (stack != null ? stack : '')
            );
          }
        }
      }
    }
  }

  /**
   * Resets warning cache when testing.
   *
   * @private
   */
  checkPropTypes.resetWarningCache = function() {
    {
      loggedTypeFailures = {};
    }
  };

  var checkPropTypes_1 = checkPropTypes;

  var has$1 = Function.call.bind(Object.prototype.hasOwnProperty);
  var printWarning$1 = function() {};

  {
    printWarning$1 = function(text) {
      var message = 'Warning: ' + text;
      if (typeof console !== 'undefined') {
        console.error(message);
      }
      try {
        // --- Welcome to debugging React ---
        // This error was thrown as a convenience so that you can use this stack
        // to find the callsite that caused this warning to fire.
        throw new Error(message);
      } catch (x) {}
    };
  }

  function emptyFunctionThatReturnsNull() {
    return null;
  }

  var factoryWithTypeCheckers = function(isValidElement, throwOnDirectAccess) {
    /* global Symbol */
    var ITERATOR_SYMBOL = typeof Symbol === 'function' && Symbol.iterator;
    var FAUX_ITERATOR_SYMBOL = '@@iterator'; // Before Symbol spec.

    /**
     * Returns the iterator method function contained on the iterable object.
     *
     * Be sure to invoke the function with the iterable as context:
     *
     *     var iteratorFn = getIteratorFn(myIterable);
     *     if (iteratorFn) {
     *       var iterator = iteratorFn.call(myIterable);
     *       ...
     *     }
     *
     * @param {?object} maybeIterable
     * @return {?function}
     */
    function getIteratorFn(maybeIterable) {
      var iteratorFn = maybeIterable && (ITERATOR_SYMBOL && maybeIterable[ITERATOR_SYMBOL] || maybeIterable[FAUX_ITERATOR_SYMBOL]);
      if (typeof iteratorFn === 'function') {
        return iteratorFn;
      }
    }

    /**
     * Collection of methods that allow declaration and validation of props that are
     * supplied to React components. Example usage:
     *
     *   var Props = require('ReactPropTypes');
     *   var MyArticle = React.createClass({
     *     propTypes: {
     *       // An optional string prop named "description".
     *       description: Props.string,
     *
     *       // A required enum prop named "category".
     *       category: Props.oneOf(['News','Photos']).isRequired,
     *
     *       // A prop named "dialog" that requires an instance of Dialog.
     *       dialog: Props.instanceOf(Dialog).isRequired
     *     },
     *     render: function() { ... }
     *   });
     *
     * A more formal specification of how these methods are used:
     *
     *   type := array|bool|func|object|number|string|oneOf([...])|instanceOf(...)
     *   decl := ReactPropTypes.{type}(.isRequired)?
     *
     * Each and every declaration produces a function with the same signature. This
     * allows the creation of custom validation functions. For example:
     *
     *  var MyLink = React.createClass({
     *    propTypes: {
     *      // An optional string or URI prop named "href".
     *      href: function(props, propName, componentName) {
     *        var propValue = props[propName];
     *        if (propValue != null && typeof propValue !== 'string' &&
     *            !(propValue instanceof URI)) {
     *          return new Error(
     *            'Expected a string or an URI for ' + propName + ' in ' +
     *            componentName
     *          );
     *        }
     *      }
     *    },
     *    render: function() {...}
     *  });
     *
     * @internal
     */

    var ANONYMOUS = '<<anonymous>>';

    // Important!
    // Keep this list in sync with production version in `./factoryWithThrowingShims.js`.
    var ReactPropTypes = {
      array: createPrimitiveTypeChecker('array'),
      bool: createPrimitiveTypeChecker('boolean'),
      func: createPrimitiveTypeChecker('function'),
      number: createPrimitiveTypeChecker('number'),
      object: createPrimitiveTypeChecker('object'),
      string: createPrimitiveTypeChecker('string'),
      symbol: createPrimitiveTypeChecker('symbol'),

      any: createAnyTypeChecker(),
      arrayOf: createArrayOfTypeChecker,
      element: createElementTypeChecker(),
      elementType: createElementTypeTypeChecker(),
      instanceOf: createInstanceTypeChecker,
      node: createNodeChecker(),
      objectOf: createObjectOfTypeChecker,
      oneOf: createEnumTypeChecker,
      oneOfType: createUnionTypeChecker,
      shape: createShapeTypeChecker,
      exact: createStrictShapeTypeChecker,
    };

    /**
     * inlined Object.is polyfill to avoid requiring consumers ship their own
     * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is
     */
    /*eslint-disable no-self-compare*/
    function is(x, y) {
      // SameValue algorithm
      if (x === y) {
        // Steps 1-5, 7-10
        // Steps 6.b-6.e: +0 != -0
        return x !== 0 || 1 / x === 1 / y;
      } else {
        // Step 6.a: NaN == NaN
        return x !== x && y !== y;
      }
    }
    /*eslint-enable no-self-compare*/

    /**
     * We use an Error-like object for backward compatibility as people may call
     * PropTypes directly and inspect their output. However, we don't use real
     * Errors anymore. We don't inspect their stack anyway, and creating them
     * is prohibitively expensive if they are created too often, such as what
     * happens in oneOfType() for any type before the one that matched.
     */
    function PropTypeError(message) {
      this.message = message;
      this.stack = '';
    }
    // Make `instanceof Error` still work for returned errors.
    PropTypeError.prototype = Error.prototype;

    function createChainableTypeChecker(validate) {
      {
        var manualPropTypeCallCache = {};
        var manualPropTypeWarningCount = 0;
      }
      function checkType(isRequired, props, propName, componentName, location, propFullName, secret) {
        componentName = componentName || ANONYMOUS;
        propFullName = propFullName || propName;

        if (secret !== ReactPropTypesSecret_1) {
          if (throwOnDirectAccess) {
            // New behavior only for users of `prop-types` package
            var err = new Error(
              'Calling PropTypes validators directly is not supported by the `prop-types` package. ' +
              'Use `PropTypes.checkPropTypes()` to call them. ' +
              'Read more at http://fb.me/use-check-prop-types'
            );
            err.name = 'Invariant Violation';
            throw err;
          } else if ( typeof console !== 'undefined') {
            // Old behavior for people using React.PropTypes
            var cacheKey = componentName + ':' + propName;
            if (
              !manualPropTypeCallCache[cacheKey] &&
              // Avoid spamming the console because they are often not actionable except for lib authors
              manualPropTypeWarningCount < 3
            ) {
              printWarning$1(
                'You are manually calling a React.PropTypes validation ' +
                'function for the `' + propFullName + '` prop on `' + componentName  + '`. This is deprecated ' +
                'and will throw in the standalone `prop-types` package. ' +
                'You may be seeing this warning due to a third-party PropTypes ' +
                'library. See https://fb.me/react-warning-dont-call-proptypes ' + 'for details.'
              );
              manualPropTypeCallCache[cacheKey] = true;
              manualPropTypeWarningCount++;
            }
          }
        }
        if (props[propName] == null) {
          if (isRequired) {
            if (props[propName] === null) {
              return new PropTypeError('The ' + location + ' `' + propFullName + '` is marked as required ' + ('in `' + componentName + '`, but its value is `null`.'));
            }
            return new PropTypeError('The ' + location + ' `' + propFullName + '` is marked as required in ' + ('`' + componentName + '`, but its value is `undefined`.'));
          }
          return null;
        } else {
          return validate(props, propName, componentName, location, propFullName);
        }
      }

      var chainedCheckType = checkType.bind(null, false);
      chainedCheckType.isRequired = checkType.bind(null, true);

      return chainedCheckType;
    }

    function createPrimitiveTypeChecker(expectedType) {
      function validate(props, propName, componentName, location, propFullName, secret) {
        var propValue = props[propName];
        var propType = getPropType(propValue);
        if (propType !== expectedType) {
          // `propValue` being instance of, say, date/regexp, pass the 'object'
          // check, but we can offer a more precise error message here rather than
          // 'of type `object`'.
          var preciseType = getPreciseType(propValue);

          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type ' + ('`' + preciseType + '` supplied to `' + componentName + '`, expected ') + ('`' + expectedType + '`.'));
        }
        return null;
      }
      return createChainableTypeChecker(validate);
    }

    function createAnyTypeChecker() {
      return createChainableTypeChecker(emptyFunctionThatReturnsNull);
    }

    function createArrayOfTypeChecker(typeChecker) {
      function validate(props, propName, componentName, location, propFullName) {
        if (typeof typeChecker !== 'function') {
          return new PropTypeError('Property `' + propFullName + '` of component `' + componentName + '` has invalid PropType notation inside arrayOf.');
        }
        var propValue = props[propName];
        if (!Array.isArray(propValue)) {
          var propType = getPropType(propValue);
          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type ' + ('`' + propType + '` supplied to `' + componentName + '`, expected an array.'));
        }
        for (var i = 0; i < propValue.length; i++) {
          var error = typeChecker(propValue, i, componentName, location, propFullName + '[' + i + ']', ReactPropTypesSecret_1);
          if (error instanceof Error) {
            return error;
          }
        }
        return null;
      }
      return createChainableTypeChecker(validate);
    }

    function createElementTypeChecker() {
      function validate(props, propName, componentName, location, propFullName) {
        var propValue = props[propName];
        if (!isValidElement(propValue)) {
          var propType = getPropType(propValue);
          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type ' + ('`' + propType + '` supplied to `' + componentName + '`, expected a single ReactElement.'));
        }
        return null;
      }
      return createChainableTypeChecker(validate);
    }

    function createElementTypeTypeChecker() {
      function validate(props, propName, componentName, location, propFullName) {
        var propValue = props[propName];
        if (!reactIs.isValidElementType(propValue)) {
          var propType = getPropType(propValue);
          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type ' + ('`' + propType + '` supplied to `' + componentName + '`, expected a single ReactElement type.'));
        }
        return null;
      }
      return createChainableTypeChecker(validate);
    }

    function createInstanceTypeChecker(expectedClass) {
      function validate(props, propName, componentName, location, propFullName) {
        if (!(props[propName] instanceof expectedClass)) {
          var expectedClassName = expectedClass.name || ANONYMOUS;
          var actualClassName = getClassName(props[propName]);
          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type ' + ('`' + actualClassName + '` supplied to `' + componentName + '`, expected ') + ('instance of `' + expectedClassName + '`.'));
        }
        return null;
      }
      return createChainableTypeChecker(validate);
    }

    function createEnumTypeChecker(expectedValues) {
      if (!Array.isArray(expectedValues)) {
        {
          if (arguments.length > 1) {
            printWarning$1(
              'Invalid arguments supplied to oneOf, expected an array, got ' + arguments.length + ' arguments. ' +
              'A common mistake is to write oneOf(x, y, z) instead of oneOf([x, y, z]).'
            );
          } else {
            printWarning$1('Invalid argument supplied to oneOf, expected an array.');
          }
        }
        return emptyFunctionThatReturnsNull;
      }

      function validate(props, propName, componentName, location, propFullName) {
        var propValue = props[propName];
        for (var i = 0; i < expectedValues.length; i++) {
          if (is(propValue, expectedValues[i])) {
            return null;
          }
        }

        var valuesString = JSON.stringify(expectedValues, function replacer(key, value) {
          var type = getPreciseType(value);
          if (type === 'symbol') {
            return String(value);
          }
          return value;
        });
        return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of value `' + String(propValue) + '` ' + ('supplied to `' + componentName + '`, expected one of ' + valuesString + '.'));
      }
      return createChainableTypeChecker(validate);
    }

    function createObjectOfTypeChecker(typeChecker) {
      function validate(props, propName, componentName, location, propFullName) {
        if (typeof typeChecker !== 'function') {
          return new PropTypeError('Property `' + propFullName + '` of component `' + componentName + '` has invalid PropType notation inside objectOf.');
        }
        var propValue = props[propName];
        var propType = getPropType(propValue);
        if (propType !== 'object') {
          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type ' + ('`' + propType + '` supplied to `' + componentName + '`, expected an object.'));
        }
        for (var key in propValue) {
          if (has$1(propValue, key)) {
            var error = typeChecker(propValue, key, componentName, location, propFullName + '.' + key, ReactPropTypesSecret_1);
            if (error instanceof Error) {
              return error;
            }
          }
        }
        return null;
      }
      return createChainableTypeChecker(validate);
    }

    function createUnionTypeChecker(arrayOfTypeCheckers) {
      if (!Array.isArray(arrayOfTypeCheckers)) {
         printWarning$1('Invalid argument supplied to oneOfType, expected an instance of array.') ;
        return emptyFunctionThatReturnsNull;
      }

      for (var i = 0; i < arrayOfTypeCheckers.length; i++) {
        var checker = arrayOfTypeCheckers[i];
        if (typeof checker !== 'function') {
          printWarning$1(
            'Invalid argument supplied to oneOfType. Expected an array of check functions, but ' +
            'received ' + getPostfixForTypeWarning(checker) + ' at index ' + i + '.'
          );
          return emptyFunctionThatReturnsNull;
        }
      }

      function validate(props, propName, componentName, location, propFullName) {
        for (var i = 0; i < arrayOfTypeCheckers.length; i++) {
          var checker = arrayOfTypeCheckers[i];
          if (checker(props, propName, componentName, location, propFullName, ReactPropTypesSecret_1) == null) {
            return null;
          }
        }

        return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` supplied to ' + ('`' + componentName + '`.'));
      }
      return createChainableTypeChecker(validate);
    }

    function createNodeChecker() {
      function validate(props, propName, componentName, location, propFullName) {
        if (!isNode(props[propName])) {
          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` supplied to ' + ('`' + componentName + '`, expected a ReactNode.'));
        }
        return null;
      }
      return createChainableTypeChecker(validate);
    }

    function createShapeTypeChecker(shapeTypes) {
      function validate(props, propName, componentName, location, propFullName) {
        var propValue = props[propName];
        var propType = getPropType(propValue);
        if (propType !== 'object') {
          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type `' + propType + '` ' + ('supplied to `' + componentName + '`, expected `object`.'));
        }
        for (var key in shapeTypes) {
          var checker = shapeTypes[key];
          if (!checker) {
            continue;
          }
          var error = checker(propValue, key, componentName, location, propFullName + '.' + key, ReactPropTypesSecret_1);
          if (error) {
            return error;
          }
        }
        return null;
      }
      return createChainableTypeChecker(validate);
    }

    function createStrictShapeTypeChecker(shapeTypes) {
      function validate(props, propName, componentName, location, propFullName) {
        var propValue = props[propName];
        var propType = getPropType(propValue);
        if (propType !== 'object') {
          return new PropTypeError('Invalid ' + location + ' `' + propFullName + '` of type `' + propType + '` ' + ('supplied to `' + componentName + '`, expected `object`.'));
        }
        // We need to check all keys in case some are required but missing from
        // props.
        var allKeys = objectAssign({}, props[propName], shapeTypes);
        for (var key in allKeys) {
          var checker = shapeTypes[key];
          if (!checker) {
            return new PropTypeError(
              'Invalid ' + location + ' `' + propFullName + '` key `' + key + '` supplied to `' + componentName + '`.' +
              '\nBad object: ' + JSON.stringify(props[propName], null, '  ') +
              '\nValid keys: ' +  JSON.stringify(Object.keys(shapeTypes), null, '  ')
            );
          }
          var error = checker(propValue, key, componentName, location, propFullName + '.' + key, ReactPropTypesSecret_1);
          if (error) {
            return error;
          }
        }
        return null;
      }

      return createChainableTypeChecker(validate);
    }

    function isNode(propValue) {
      switch (typeof propValue) {
        case 'number':
        case 'string':
        case 'undefined':
          return true;
        case 'boolean':
          return !propValue;
        case 'object':
          if (Array.isArray(propValue)) {
            return propValue.every(isNode);
          }
          if (propValue === null || isValidElement(propValue)) {
            return true;
          }

          var iteratorFn = getIteratorFn(propValue);
          if (iteratorFn) {
            var iterator = iteratorFn.call(propValue);
            var step;
            if (iteratorFn !== propValue.entries) {
              while (!(step = iterator.next()).done) {
                if (!isNode(step.value)) {
                  return false;
                }
              }
            } else {
              // Iterator will provide entry [k,v] tuples rather than values.
              while (!(step = iterator.next()).done) {
                var entry = step.value;
                if (entry) {
                  if (!isNode(entry[1])) {
                    return false;
                  }
                }
              }
            }
          } else {
            return false;
          }

          return true;
        default:
          return false;
      }
    }

    function isSymbol(propType, propValue) {
      // Native Symbol.
      if (propType === 'symbol') {
        return true;
      }

      // falsy value can't be a Symbol
      if (!propValue) {
        return false;
      }

      // 19.4.3.5 Symbol.prototype[@@toStringTag] === 'Symbol'
      if (propValue['@@toStringTag'] === 'Symbol') {
        return true;
      }

      // Fallback for non-spec compliant Symbols which are polyfilled.
      if (typeof Symbol === 'function' && propValue instanceof Symbol) {
        return true;
      }

      return false;
    }

    // Equivalent of `typeof` but with special handling for array and regexp.
    function getPropType(propValue) {
      var propType = typeof propValue;
      if (Array.isArray(propValue)) {
        return 'array';
      }
      if (propValue instanceof RegExp) {
        // Old webkits (at least until Android 4.0) return 'function' rather than
        // 'object' for typeof a RegExp. We'll normalize this here so that /bla/
        // passes PropTypes.object.
        return 'object';
      }
      if (isSymbol(propType, propValue)) {
        return 'symbol';
      }
      return propType;
    }

    // This handles more types than `getPropType`. Only used for error messages.
    // See `createPrimitiveTypeChecker`.
    function getPreciseType(propValue) {
      if (typeof propValue === 'undefined' || propValue === null) {
        return '' + propValue;
      }
      var propType = getPropType(propValue);
      if (propType === 'object') {
        if (propValue instanceof Date) {
          return 'date';
        } else if (propValue instanceof RegExp) {
          return 'regexp';
        }
      }
      return propType;
    }

    // Returns a string that is postfixed to a warning about an invalid type.
    // For example, "undefined" or "of type array"
    function getPostfixForTypeWarning(value) {
      var type = getPreciseType(value);
      switch (type) {
        case 'array':
        case 'object':
          return 'an ' + type;
        case 'boolean':
        case 'date':
        case 'regexp':
          return 'a ' + type;
        default:
          return type;
      }
    }

    // Returns class name of the object, if any.
    function getClassName(propValue) {
      if (!propValue.constructor || !propValue.constructor.name) {
        return ANONYMOUS;
      }
      return propValue.constructor.name;
    }

    ReactPropTypes.checkPropTypes = checkPropTypes_1;
    ReactPropTypes.resetWarningCache = checkPropTypes_1.resetWarningCache;
    ReactPropTypes.PropTypes = ReactPropTypes;

    return ReactPropTypes;
  };

  var propTypes = createCommonjsModule(function (module) {
  /**
   * Copyright (c) 2013-present, Facebook, Inc.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   */

  {
    var ReactIs = reactIs;

    // By explicitly using `prop-types` you are opting into new development behavior.
    // http://fb.me/prop-types-in-prod
    var throwOnDirectAccess = true;
    module.exports = factoryWithTypeCheckers(ReactIs.isElement, throwOnDirectAccess);
  }
  });

  function _extends() {
    _extends = Object.assign || function (target) {
      for (var i = 1; i < arguments.length; i++) {
        var source = arguments[i];

        for (var key in source) {
          if (Object.prototype.hasOwnProperty.call(source, key)) {
            target[key] = source[key];
          }
        }
      }

      return target;
    };

    return _extends.apply(this, arguments);
  }

  function isAbsolute(pathname) {
    return pathname.charAt(0) === '/';
  }

  // About 1.5x faster than the two-arg version of Array#splice()
  function spliceOne(list, index) {
    for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1) {
      list[i] = list[k];
    }

    list.pop();
  }

  // This implementation is based heavily on node's url.parse
  function resolvePathname(to) {
    var from = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : '';

    var toParts = to && to.split('/') || [];
    var fromParts = from && from.split('/') || [];

    var isToAbs = to && isAbsolute(to);
    var isFromAbs = from && isAbsolute(from);
    var mustEndAbs = isToAbs || isFromAbs;

    if (to && isAbsolute(to)) {
      // to is absolute
      fromParts = toParts;
    } else if (toParts.length) {
      // to is relative, drop the filename
      fromParts.pop();
      fromParts = fromParts.concat(toParts);
    }

    if (!fromParts.length) return '/';

    var hasTrailingSlash = void 0;
    if (fromParts.length) {
      var last = fromParts[fromParts.length - 1];
      hasTrailingSlash = last === '.' || last === '..' || last === '';
    } else {
      hasTrailingSlash = false;
    }

    var up = 0;
    for (var i = fromParts.length; i >= 0; i--) {
      var part = fromParts[i];

      if (part === '.') {
        spliceOne(fromParts, i);
      } else if (part === '..') {
        spliceOne(fromParts, i);
        up++;
      } else if (up) {
        spliceOne(fromParts, i);
        up--;
      }
    }

    if (!mustEndAbs) for (; up--; up) {
      fromParts.unshift('..');
    }if (mustEndAbs && fromParts[0] !== '' && (!fromParts[0] || !isAbsolute(fromParts[0]))) fromParts.unshift('');

    var result = fromParts.join('/');

    if (hasTrailingSlash && result.substr(-1) !== '/') result += '/';

    return result;
  }

  var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

  function valueEqual(a, b) {
    if (a === b) return true;

    if (a == null || b == null) return false;

    if (Array.isArray(a)) {
      return Array.isArray(b) && a.length === b.length && a.every(function (item, index) {
        return valueEqual(item, b[index]);
      });
    }

    var aType = typeof a === 'undefined' ? 'undefined' : _typeof(a);
    var bType = typeof b === 'undefined' ? 'undefined' : _typeof(b);

    if (aType !== bType) return false;

    if (aType === 'object') {
      var aValue = a.valueOf();
      var bValue = b.valueOf();

      if (aValue !== a || bValue !== b) return valueEqual(aValue, bValue);

      var aKeys = Object.keys(a);
      var bKeys = Object.keys(b);

      if (aKeys.length !== bKeys.length) return false;

      return aKeys.every(function (key) {
        return valueEqual(a[key], b[key]);
      });
    }

    return false;
  }

  function warning(condition, message) {
    {
      if (condition) {
        return;
      }

      var text = "Warning: " + message;

      if (typeof console !== 'undefined') {
        console.warn(text);
      }

      try {
        throw Error(text);
      } catch (x) {}
    }
  }

  var prefix = 'Invariant failed';
  function invariant(condition, message) {
    if (condition) {
      return;
    }

    {
      throw new Error(prefix + ": " + (message || ''));
    }
  }

  function parsePath(path) {
    var pathname = path || '/';
    var search = '';
    var hash = '';
    var hashIndex = pathname.indexOf('#');

    if (hashIndex !== -1) {
      hash = pathname.substr(hashIndex);
      pathname = pathname.substr(0, hashIndex);
    }

    var searchIndex = pathname.indexOf('?');

    if (searchIndex !== -1) {
      search = pathname.substr(searchIndex);
      pathname = pathname.substr(0, searchIndex);
    }

    return {
      pathname: pathname,
      search: search === '?' ? '' : search,
      hash: hash === '#' ? '' : hash
    };
  }
  function createPath(location) {
    var pathname = location.pathname,
        search = location.search,
        hash = location.hash;
    var path = pathname || '/';
    if (search && search !== '?') path += search.charAt(0) === '?' ? search : "?" + search;
    if (hash && hash !== '#') path += hash.charAt(0) === '#' ? hash : "#" + hash;
    return path;
  }

  function createLocation(path, state, key, currentLocation) {
    var location;

    if (typeof path === 'string') {
      // Two-arg form: push(path, state)
      location = parsePath(path);
      location.state = state;
    } else {
      // One-arg form: push(location)
      location = _extends({}, path);
      if (location.pathname === undefined) location.pathname = '';

      if (location.search) {
        if (location.search.charAt(0) !== '?') location.search = '?' + location.search;
      } else {
        location.search = '';
      }

      if (location.hash) {
        if (location.hash.charAt(0) !== '#') location.hash = '#' + location.hash;
      } else {
        location.hash = '';
      }

      if (state !== undefined && location.state === undefined) location.state = state;
    }

    try {
      location.pathname = decodeURI(location.pathname);
    } catch (e) {
      if (e instanceof URIError) {
        throw new URIError('Pathname "' + location.pathname + '" could not be decoded. ' + 'This is likely caused by an invalid percent-encoding.');
      } else {
        throw e;
      }
    }

    if (key) location.key = key;

    if (currentLocation) {
      // Resolve incomplete/relative pathname relative to current location.
      if (!location.pathname) {
        location.pathname = currentLocation.pathname;
      } else if (location.pathname.charAt(0) !== '/') {
        location.pathname = resolvePathname(location.pathname, currentLocation.pathname);
      }
    } else {
      // When there is no prior location and pathname is empty, set it to /
      if (!location.pathname) {
        location.pathname = '/';
      }
    }

    return location;
  }
  function locationsAreEqual(a, b) {
    return a.pathname === b.pathname && a.search === b.search && a.hash === b.hash && a.key === b.key && valueEqual(a.state, b.state);
  }

  function createTransitionManager() {
    var prompt = null;

    function setPrompt(nextPrompt) {
       warning(prompt == null, 'A history supports only one prompt at a time') ;
      prompt = nextPrompt;
      return function () {
        if (prompt === nextPrompt) prompt = null;
      };
    }

    function confirmTransitionTo(location, action, getUserConfirmation, callback) {
      // TODO: If another transition starts while we're still confirming
      // the previous one, we may end up in a weird state. Figure out the
      // best way to handle this.
      if (prompt != null) {
        var result = typeof prompt === 'function' ? prompt(location, action) : prompt;

        if (typeof result === 'string') {
          if (typeof getUserConfirmation === 'function') {
            getUserConfirmation(result, callback);
          } else {
             warning(false, 'A history needs a getUserConfirmation function in order to use a prompt message') ;
            callback(true);
          }
        } else {
          // Return false from a transition hook to cancel the transition.
          callback(result !== false);
        }
      } else {
        callback(true);
      }
    }

    var listeners = [];

    function appendListener(fn) {
      var isActive = true;

      function listener() {
        if (isActive) fn.apply(void 0, arguments);
      }

      listeners.push(listener);
      return function () {
        isActive = false;
        listeners = listeners.filter(function (item) {
          return item !== listener;
        });
      };
    }

    function notifyListeners() {
      for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
        args[_key] = arguments[_key];
      }

      listeners.forEach(function (listener) {
        return listener.apply(void 0, args);
      });
    }

    return {
      setPrompt: setPrompt,
      confirmTransitionTo: confirmTransitionTo,
      appendListener: appendListener,
      notifyListeners: notifyListeners
    };
  }

  var canUseDOM = !!(typeof window !== 'undefined' && window.document && window.document.createElement);

  function clamp(n, lowerBound, upperBound) {
    return Math.min(Math.max(n, lowerBound), upperBound);
  }
  /**
   * Creates a history object that stores locations in memory.
   */


  function createMemoryHistory(props) {
    if (props === void 0) {
      props = {};
    }

    var _props = props,
        getUserConfirmation = _props.getUserConfirmation,
        _props$initialEntries = _props.initialEntries,
        initialEntries = _props$initialEntries === void 0 ? ['/'] : _props$initialEntries,
        _props$initialIndex = _props.initialIndex,
        initialIndex = _props$initialIndex === void 0 ? 0 : _props$initialIndex,
        _props$keyLength = _props.keyLength,
        keyLength = _props$keyLength === void 0 ? 6 : _props$keyLength;
    var transitionManager = createTransitionManager();

    function setState(nextState) {
      _extends(history, nextState);

      history.length = history.entries.length;
      transitionManager.notifyListeners(history.location, history.action);
    }

    function createKey() {
      return Math.random().toString(36).substr(2, keyLength);
    }

    var index = clamp(initialIndex, 0, initialEntries.length - 1);
    var entries = initialEntries.map(function (entry) {
      return typeof entry === 'string' ? createLocation(entry, undefined, createKey()) : createLocation(entry, undefined, entry.key || createKey());
    }); // Public interface

    var createHref = createPath;

    function push(path, state) {
       warning(!(typeof path === 'object' && path.state !== undefined && state !== undefined), 'You should avoid providing a 2nd state argument to push when the 1st ' + 'argument is a location-like object that already has state; it is ignored') ;
      var action = 'PUSH';
      var location = createLocation(path, state, createKey(), history.location);
      transitionManager.confirmTransitionTo(location, action, getUserConfirmation, function (ok) {
        if (!ok) return;
        var prevIndex = history.index;
        var nextIndex = prevIndex + 1;
        var nextEntries = history.entries.slice(0);

        if (nextEntries.length > nextIndex) {
          nextEntries.splice(nextIndex, nextEntries.length - nextIndex, location);
        } else {
          nextEntries.push(location);
        }

        setState({
          action: action,
          location: location,
          index: nextIndex,
          entries: nextEntries
        });
      });
    }

    function replace(path, state) {
       warning(!(typeof path === 'object' && path.state !== undefined && state !== undefined), 'You should avoid providing a 2nd state argument to replace when the 1st ' + 'argument is a location-like object that already has state; it is ignored') ;
      var action = 'REPLACE';
      var location = createLocation(path, state, createKey(), history.location);
      transitionManager.confirmTransitionTo(location, action, getUserConfirmation, function (ok) {
        if (!ok) return;
        history.entries[history.index] = location;
        setState({
          action: action,
          location: location
        });
      });
    }

    function go(n) {
      var nextIndex = clamp(history.index + n, 0, history.entries.length - 1);
      var action = 'POP';
      var location = history.entries[nextIndex];
      transitionManager.confirmTransitionTo(location, action, getUserConfirmation, function (ok) {
        if (ok) {
          setState({
            action: action,
            location: location,
            index: nextIndex
          });
        } else {
          // Mimic the behavior of DOM histories by
          // causing a render after a cancelled POP.
          setState();
        }
      });
    }

    function goBack() {
      go(-1);
    }

    function goForward() {
      go(1);
    }

    function canGo(n) {
      var nextIndex = history.index + n;
      return nextIndex >= 0 && nextIndex < history.entries.length;
    }

    function block(prompt) {
      if (prompt === void 0) {
        prompt = false;
      }

      return transitionManager.setPrompt(prompt);
    }

    function listen(listener) {
      return transitionManager.appendListener(listener);
    }

    var history = {
      length: entries.length,
      action: 'POP',
      location: entries[index],
      index: index,
      entries: entries,
      createHref: createHref,
      push: push,
      replace: replace,
      go: go,
      goBack: goBack,
      goForward: goForward,
      canGo: canGo,
      block: block,
      listen: listen
    };
    return history;
  }

  var MAX_SIGNED_31_BIT_INT = 1073741823;
  var commonjsGlobal = typeof globalThis !== 'undefined' ? globalThis : typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : {};

  function getUniqueId() {
    var key = '__global_unique_id__';
    return commonjsGlobal[key] = (commonjsGlobal[key] || 0) + 1;
  }

  function objectIs(x, y) {
    if (x === y) {
      return x !== 0 || 1 / x === 1 / y;
    } else {
      return x !== x && y !== y;
    }
  }

  function createEventEmitter(value) {
    var handlers = [];
    return {
      on: function on(handler) {
        handlers.push(handler);
      },
      off: function off(handler) {
        handlers = handlers.filter(function (h) {
          return h !== handler;
        });
      },
      get: function get() {
        return value;
      },
      set: function set(newValue, changedBits) {
        value = newValue;
        handlers.forEach(function (handler) {
          return handler(value, changedBits);
        });
      }
    };
  }

  function onlyChild(children) {
    return Array.isArray(children) ? children[0] : children;
  }

  function createReactContext(defaultValue, calculateChangedBits) {
    var _Provider$childContex, _Consumer$contextType;

    var contextProp = '__create-react-context-' + getUniqueId() + '__';

    var Provider = /*#__PURE__*/function (_Component) {
      _inheritsLoose(Provider, _Component);

      function Provider() {
        var _this;

        _this = _Component.apply(this, arguments) || this;
        _this.emitter = createEventEmitter(_this.props.value);
        return _this;
      }

      var _proto = Provider.prototype;

      _proto.getChildContext = function getChildContext() {
        var _ref;

        return _ref = {}, _ref[contextProp] = this.emitter, _ref;
      };

      _proto.componentWillReceiveProps = function componentWillReceiveProps(nextProps) {
        if (this.props.value !== nextProps.value) {
          var oldValue = this.props.value;
          var newValue = nextProps.value;
          var changedBits;

          if (objectIs(oldValue, newValue)) {
            changedBits = 0;
          } else {
            changedBits = typeof calculateChangedBits === 'function' ? calculateChangedBits(oldValue, newValue) : MAX_SIGNED_31_BIT_INT;

            {
              warning((changedBits & MAX_SIGNED_31_BIT_INT) === changedBits, 'calculateChangedBits: Expected the return value to be a ' + '31-bit integer. Instead received: ' + changedBits);
            }

            changedBits |= 0;

            if (changedBits !== 0) {
              this.emitter.set(nextProps.value, changedBits);
            }
          }
        }
      };

      _proto.render = function render() {
        return this.props.children;
      };

      return Provider;
    }(React.Component);

    Provider.childContextTypes = (_Provider$childContex = {}, _Provider$childContex[contextProp] = propTypes.object.isRequired, _Provider$childContex);

    var Consumer = /*#__PURE__*/function (_Component2) {
      _inheritsLoose(Consumer, _Component2);

      function Consumer() {
        var _this2;

        _this2 = _Component2.apply(this, arguments) || this;
        _this2.state = {
          value: _this2.getValue()
        };

        _this2.onUpdate = function (newValue, changedBits) {
          var observedBits = _this2.observedBits | 0;

          if ((observedBits & changedBits) !== 0) {
            _this2.setState({
              value: _this2.getValue()
            });
          }
        };

        return _this2;
      }

      var _proto2 = Consumer.prototype;

      _proto2.componentWillReceiveProps = function componentWillReceiveProps(nextProps) {
        var observedBits = nextProps.observedBits;
        this.observedBits = observedBits === undefined || observedBits === null ? MAX_SIGNED_31_BIT_INT : observedBits;
      };

      _proto2.componentDidMount = function componentDidMount() {
        if (this.context[contextProp]) {
          this.context[contextProp].on(this.onUpdate);
        }

        var observedBits = this.props.observedBits;
        this.observedBits = observedBits === undefined || observedBits === null ? MAX_SIGNED_31_BIT_INT : observedBits;
      };

      _proto2.componentWillUnmount = function componentWillUnmount() {
        if (this.context[contextProp]) {
          this.context[contextProp].off(this.onUpdate);
        }
      };

      _proto2.getValue = function getValue() {
        if (this.context[contextProp]) {
          return this.context[contextProp].get();
        } else {
          return defaultValue;
        }
      };

      _proto2.render = function render() {
        return onlyChild(this.props.children)(this.state.value);
      };

      return Consumer;
    }(React.Component);

    Consumer.contextTypes = (_Consumer$contextType = {}, _Consumer$contextType[contextProp] = propTypes.object, _Consumer$contextType);
    return {
      Provider: Provider,
      Consumer: Consumer
    };
  }

  var index = React__default.createContext || createReactContext;

  // TODO: Replace with React.createContext once we can assume React 16+

  var createNamedContext = function createNamedContext(name) {
    var context = index();
    context.displayName = name;
    return context;
  };

  var historyContext = /*#__PURE__*/createNamedContext("Router-History");

  var context = /*#__PURE__*/createNamedContext("Router");

  /**
   * The public API for putting history on context.
   */

  var Router = /*#__PURE__*/function (_React$Component) {
    _inheritsLoose(Router, _React$Component);

    Router.computeRootMatch = function computeRootMatch(pathname) {
      return {
        path: "/",
        url: "/",
        params: {},
        isExact: pathname === "/"
      };
    };

    function Router(props) {
      var _this;

      _this = _React$Component.call(this, props) || this;
      _this.state = {
        location: props.history.location
      }; // This is a bit of a hack. We have to start listening for location
      // changes here in the constructor in case there are any <Redirect>s
      // on the initial render. If there are, they will replace/push when
      // they mount and since cDM fires in children before parents, we may
      // get a new location before the <Router> is mounted.

      _this._isMounted = false;
      _this._pendingLocation = null;

      if (!props.staticContext) {
        _this.unlisten = props.history.listen(function (location) {
          if (_this._isMounted) {
            _this.setState({
              location: location
            });
          } else {
            _this._pendingLocation = location;
          }
        });
      }

      return _this;
    }

    var _proto = Router.prototype;

    _proto.componentDidMount = function componentDidMount() {
      this._isMounted = true;

      if (this._pendingLocation) {
        this.setState({
          location: this._pendingLocation
        });
      }
    };

    _proto.componentWillUnmount = function componentWillUnmount() {
      if (this.unlisten) {
        this.unlisten();
        this._isMounted = false;
        this._pendingLocation = null;
      }
    };

    _proto.render = function render() {
      return /*#__PURE__*/React__default.createElement(context.Provider, {
        value: {
          history: this.props.history,
          location: this.state.location,
          match: Router.computeRootMatch(this.state.location.pathname),
          staticContext: this.props.staticContext
        }
      }, /*#__PURE__*/React__default.createElement(historyContext.Provider, {
        children: this.props.children || null,
        value: this.props.history
      }));
    };

    return Router;
  }(React__default.Component);

  {
    Router.propTypes = {
      children: propTypes.node,
      history: propTypes.object.isRequired,
      staticContext: propTypes.object
    };

    Router.prototype.componentDidUpdate = function (prevProps) {
       warning(prevProps.history === this.props.history, "You cannot change <Router history>") ;
    };
  }

  /**
   * The public API for a <Router> that stores location in memory.
   */

  var MemoryRouter = /*#__PURE__*/function (_React$Component) {
    _inheritsLoose(MemoryRouter, _React$Component);

    function MemoryRouter() {
      var _this;

      for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
        args[_key] = arguments[_key];
      }

      _this = _React$Component.call.apply(_React$Component, [this].concat(args)) || this;
      _this.history = createMemoryHistory(_this.props);
      return _this;
    }

    var _proto = MemoryRouter.prototype;

    _proto.render = function render() {
      return /*#__PURE__*/React__default.createElement(Router, {
        history: this.history,
        children: this.props.children
      });
    };

    return MemoryRouter;
  }(React__default.Component);

  {
    MemoryRouter.propTypes = {
      initialEntries: propTypes.array,
      initialIndex: propTypes.number,
      getUserConfirmation: propTypes.func,
      keyLength: propTypes.number,
      children: propTypes.node
    };

    MemoryRouter.prototype.componentDidMount = function () {
       warning(!this.props.history, "<MemoryRouter> ignores the history prop. To use a custom history, " + "use `import { Router }` instead of `import { MemoryRouter as Router }`.") ;
    };
  }

  var Lifecycle = /*#__PURE__*/function (_React$Component) {
    _inheritsLoose(Lifecycle, _React$Component);

    function Lifecycle() {
      return _React$Component.apply(this, arguments) || this;
    }

    var _proto = Lifecycle.prototype;

    _proto.componentDidMount = function componentDidMount() {
      if (this.props.onMount) this.props.onMount.call(this, this);
    };

    _proto.componentDidUpdate = function componentDidUpdate(prevProps) {
      if (this.props.onUpdate) this.props.onUpdate.call(this, this, prevProps);
    };

    _proto.componentWillUnmount = function componentWillUnmount() {
      if (this.props.onUnmount) this.props.onUnmount.call(this, this);
    };

    _proto.render = function render() {
      return null;
    };

    return Lifecycle;
  }(React__default.Component);

  /**
   * The public API for prompting the user before navigating away from a screen.
   */

  function Prompt(_ref) {
    var message = _ref.message,
        _ref$when = _ref.when,
        when = _ref$when === void 0 ? true : _ref$when;
    return /*#__PURE__*/React__default.createElement(context.Consumer, null, function (context) {
      !context ?  invariant(false, "You should not use <Prompt> outside a <Router>")  : void 0;
      if (!when || context.staticContext) return null;
      var method = context.history.block;
      return /*#__PURE__*/React__default.createElement(Lifecycle, {
        onMount: function onMount(self) {
          self.release = method(message);
        },
        onUpdate: function onUpdate(self, prevProps) {
          if (prevProps.message !== message) {
            self.release();
            self.release = method(message);
          }
        },
        onUnmount: function onUnmount(self) {
          self.release();
        },
        message: message
      });
    });
  }

  {
    var messageType = propTypes.oneOfType([propTypes.func, propTypes.string]);
    Prompt.propTypes = {
      when: propTypes.bool,
      message: messageType.isRequired
    };
  }

  var isarray = Array.isArray || function (arr) {
    return Object.prototype.toString.call(arr) == '[object Array]';
  };

  /**
   * Expose `pathToRegexp`.
   */
  var pathToRegexp_1 = pathToRegexp;
  var parse_1 = parse;
  var compile_1 = compile;
  var tokensToFunction_1 = tokensToFunction;
  var tokensToRegExp_1 = tokensToRegExp;

  /**
   * The main path matching regexp utility.
   *
   * @type {RegExp}
   */
  var PATH_REGEXP = new RegExp([
    // Match escaped characters that would otherwise appear in future matches.
    // This allows the user to escape special characters that won't transform.
    '(\\\\.)',
    // Match Express-style parameters and un-named parameters with a prefix
    // and optional suffixes. Matches appear as:
    //
    // "/:test(\\d+)?" => ["/", "test", "\d+", undefined, "?", undefined]
    // "/route(\\d+)"  => [undefined, undefined, undefined, "\d+", undefined, undefined]
    // "/*"            => ["/", undefined, undefined, undefined, undefined, "*"]
    '([\\/.])?(?:(?:\\:(\\w+)(?:\\(((?:\\\\.|[^\\\\()])+)\\))?|\\(((?:\\\\.|[^\\\\()])+)\\))([+*?])?|(\\*))'
  ].join('|'), 'g');

  /**
   * Parse a string for the raw tokens.
   *
   * @param  {string}  str
   * @param  {Object=} options
   * @return {!Array}
   */
  function parse (str, options) {
    var tokens = [];
    var key = 0;
    var index = 0;
    var path = '';
    var defaultDelimiter = options && options.delimiter || '/';
    var res;

    while ((res = PATH_REGEXP.exec(str)) != null) {
      var m = res[0];
      var escaped = res[1];
      var offset = res.index;
      path += str.slice(index, offset);
      index = offset + m.length;

      // Ignore already escaped sequences.
      if (escaped) {
        path += escaped[1];
        continue
      }

      var next = str[index];
      var prefix = res[2];
      var name = res[3];
      var capture = res[4];
      var group = res[5];
      var modifier = res[6];
      var asterisk = res[7];

      // Push the current path onto the tokens.
      if (path) {
        tokens.push(path);
        path = '';
      }

      var partial = prefix != null && next != null && next !== prefix;
      var repeat = modifier === '+' || modifier === '*';
      var optional = modifier === '?' || modifier === '*';
      var delimiter = res[2] || defaultDelimiter;
      var pattern = capture || group;

      tokens.push({
        name: name || key++,
        prefix: prefix || '',
        delimiter: delimiter,
        optional: optional,
        repeat: repeat,
        partial: partial,
        asterisk: !!asterisk,
        pattern: pattern ? escapeGroup(pattern) : (asterisk ? '.*' : '[^' + escapeString(delimiter) + ']+?')
      });
    }

    // Match any characters still remaining.
    if (index < str.length) {
      path += str.substr(index);
    }

    // If the path exists, push it onto the end.
    if (path) {
      tokens.push(path);
    }

    return tokens
  }

  /**
   * Compile a string to a template function for the path.
   *
   * @param  {string}             str
   * @param  {Object=}            options
   * @return {!function(Object=, Object=)}
   */
  function compile (str, options) {
    return tokensToFunction(parse(str, options))
  }

  /**
   * Prettier encoding of URI path segments.
   *
   * @param  {string}
   * @return {string}
   */
  function encodeURIComponentPretty (str) {
    return encodeURI(str).replace(/[\/?#]/g, function (c) {
      return '%' + c.charCodeAt(0).toString(16).toUpperCase()
    })
  }

  /**
   * Encode the asterisk parameter. Similar to `pretty`, but allows slashes.
   *
   * @param  {string}
   * @return {string}
   */
  function encodeAsterisk (str) {
    return encodeURI(str).replace(/[?#]/g, function (c) {
      return '%' + c.charCodeAt(0).toString(16).toUpperCase()
    })
  }

  /**
   * Expose a method for transforming tokens into the path function.
   */
  function tokensToFunction (tokens) {
    // Compile all the tokens into regexps.
    var matches = new Array(tokens.length);

    // Compile all the patterns before compilation.
    for (var i = 0; i < tokens.length; i++) {
      if (typeof tokens[i] === 'object') {
        matches[i] = new RegExp('^(?:' + tokens[i].pattern + ')$');
      }
    }

    return function (obj, opts) {
      var path = '';
      var data = obj || {};
      var options = opts || {};
      var encode = options.pretty ? encodeURIComponentPretty : encodeURIComponent;

      for (var i = 0; i < tokens.length; i++) {
        var token = tokens[i];

        if (typeof token === 'string') {
          path += token;

          continue
        }

        var value = data[token.name];
        var segment;

        if (value == null) {
          if (token.optional) {
            // Prepend partial segment prefixes.
            if (token.partial) {
              path += token.prefix;
            }

            continue
          } else {
            throw new TypeError('Expected "' + token.name + '" to be defined')
          }
        }

        if (isarray(value)) {
          if (!token.repeat) {
            throw new TypeError('Expected "' + token.name + '" to not repeat, but received `' + JSON.stringify(value) + '`')
          }

          if (value.length === 0) {
            if (token.optional) {
              continue
            } else {
              throw new TypeError('Expected "' + token.name + '" to not be empty')
            }
          }

          for (var j = 0; j < value.length; j++) {
            segment = encode(value[j]);

            if (!matches[i].test(segment)) {
              throw new TypeError('Expected all "' + token.name + '" to match "' + token.pattern + '", but received `' + JSON.stringify(segment) + '`')
            }

            path += (j === 0 ? token.prefix : token.delimiter) + segment;
          }

          continue
        }

        segment = token.asterisk ? encodeAsterisk(value) : encode(value);

        if (!matches[i].test(segment)) {
          throw new TypeError('Expected "' + token.name + '" to match "' + token.pattern + '", but received "' + segment + '"')
        }

        path += token.prefix + segment;
      }

      return path
    }
  }

  /**
   * Escape a regular expression string.
   *
   * @param  {string} str
   * @return {string}
   */
  function escapeString (str) {
    return str.replace(/([.+*?=^!:${}()[\]|\/\\])/g, '\\$1')
  }

  /**
   * Escape the capturing group by escaping special characters and meaning.
   *
   * @param  {string} group
   * @return {string}
   */
  function escapeGroup (group) {
    return group.replace(/([=!:$\/()])/g, '\\$1')
  }

  /**
   * Attach the keys as a property of the regexp.
   *
   * @param  {!RegExp} re
   * @param  {Array}   keys
   * @return {!RegExp}
   */
  function attachKeys (re, keys) {
    re.keys = keys;
    return re
  }

  /**
   * Get the flags for a regexp from the options.
   *
   * @param  {Object} options
   * @return {string}
   */
  function flags (options) {
    return options.sensitive ? '' : 'i'
  }

  /**
   * Pull out keys from a regexp.
   *
   * @param  {!RegExp} path
   * @param  {!Array}  keys
   * @return {!RegExp}
   */
  function regexpToRegexp (path, keys) {
    // Use a negative lookahead to match only capturing groups.
    var groups = path.source.match(/\((?!\?)/g);

    if (groups) {
      for (var i = 0; i < groups.length; i++) {
        keys.push({
          name: i,
          prefix: null,
          delimiter: null,
          optional: false,
          repeat: false,
          partial: false,
          asterisk: false,
          pattern: null
        });
      }
    }

    return attachKeys(path, keys)
  }

  /**
   * Transform an array into a regexp.
   *
   * @param  {!Array}  path
   * @param  {Array}   keys
   * @param  {!Object} options
   * @return {!RegExp}
   */
  function arrayToRegexp (path, keys, options) {
    var parts = [];

    for (var i = 0; i < path.length; i++) {
      parts.push(pathToRegexp(path[i], keys, options).source);
    }

    var regexp = new RegExp('(?:' + parts.join('|') + ')', flags(options));

    return attachKeys(regexp, keys)
  }

  /**
   * Create a path regexp from string input.
   *
   * @param  {string}  path
   * @param  {!Array}  keys
   * @param  {!Object} options
   * @return {!RegExp}
   */
  function stringToRegexp (path, keys, options) {
    return tokensToRegExp(parse(path, options), keys, options)
  }

  /**
   * Expose a function for taking tokens and returning a RegExp.
   *
   * @param  {!Array}          tokens
   * @param  {(Array|Object)=} keys
   * @param  {Object=}         options
   * @return {!RegExp}
   */
  function tokensToRegExp (tokens, keys, options) {
    if (!isarray(keys)) {
      options = /** @type {!Object} */ (keys || options);
      keys = [];
    }

    options = options || {};

    var strict = options.strict;
    var end = options.end !== false;
    var route = '';

    // Iterate over the tokens and create our regexp string.
    for (var i = 0; i < tokens.length; i++) {
      var token = tokens[i];

      if (typeof token === 'string') {
        route += escapeString(token);
      } else {
        var prefix = escapeString(token.prefix);
        var capture = '(?:' + token.pattern + ')';

        keys.push(token);

        if (token.repeat) {
          capture += '(?:' + prefix + capture + ')*';
        }

        if (token.optional) {
          if (!token.partial) {
            capture = '(?:' + prefix + '(' + capture + '))?';
          } else {
            capture = prefix + '(' + capture + ')?';
          }
        } else {
          capture = prefix + '(' + capture + ')';
        }

        route += capture;
      }
    }

    var delimiter = escapeString(options.delimiter || '/');
    var endsWithDelimiter = route.slice(-delimiter.length) === delimiter;

    // In non-strict mode we allow a slash at the end of match. If the path to
    // match already ends with a slash, we remove it for consistency. The slash
    // is valid at the end of a path match, not in the middle. This is important
    // in non-ending mode, where "/test/" shouldn't match "/test//route".
    if (!strict) {
      route = (endsWithDelimiter ? route.slice(0, -delimiter.length) : route) + '(?:' + delimiter + '(?=$))?';
    }

    if (end) {
      route += '$';
    } else {
      // In non-ending mode, we need the capturing groups to match as much as
      // possible by using a positive lookahead to the end or next path segment.
      route += strict && endsWithDelimiter ? '' : '(?=' + delimiter + '|$)';
    }

    return attachKeys(new RegExp('^' + route, flags(options)), keys)
  }

  /**
   * Normalize the given path string, returning a regular expression.
   *
   * An empty array can be passed in for the keys, which will hold the
   * placeholder key descriptions. For example, using `/user/:id`, `keys` will
   * contain `[{ name: 'id', delimiter: '/', optional: false, repeat: false }]`.
   *
   * @param  {(string|RegExp|Array)} path
   * @param  {(Array|Object)=}       keys
   * @param  {Object=}               options
   * @return {!RegExp}
   */
  function pathToRegexp (path, keys, options) {
    if (!isarray(keys)) {
      options = /** @type {!Object} */ (keys || options);
      keys = [];
    }

    options = options || {};

    if (path instanceof RegExp) {
      return regexpToRegexp(path, /** @type {!Array} */ (keys))
    }

    if (isarray(path)) {
      return arrayToRegexp(/** @type {!Array} */ (path), /** @type {!Array} */ (keys), options)
    }

    return stringToRegexp(/** @type {string} */ (path), /** @type {!Array} */ (keys), options)
  }
  pathToRegexp_1.parse = parse_1;
  pathToRegexp_1.compile = compile_1;
  pathToRegexp_1.tokensToFunction = tokensToFunction_1;
  pathToRegexp_1.tokensToRegExp = tokensToRegExp_1;

  var cache = {};
  var cacheLimit = 10000;
  var cacheCount = 0;

  function compilePath(path) {
    if (cache[path]) return cache[path];
    var generator = pathToRegexp_1.compile(path);

    if (cacheCount < cacheLimit) {
      cache[path] = generator;
      cacheCount++;
    }

    return generator;
  }
  /**
   * Public API for generating a URL pathname from a path and parameters.
   */


  function generatePath(path, params) {
    if (path === void 0) {
      path = "/";
    }

    if (params === void 0) {
      params = {};
    }

    return path === "/" ? path : compilePath(path)(params, {
      pretty: true
    });
  }

  /**
   * The public API for navigating programmatically with a component.
   */

  function Redirect(_ref) {
    var computedMatch = _ref.computedMatch,
        to = _ref.to,
        _ref$push = _ref.push,
        push = _ref$push === void 0 ? false : _ref$push;
    return /*#__PURE__*/React__default.createElement(context.Consumer, null, function (context) {
      !context ?  invariant(false, "You should not use <Redirect> outside a <Router>")  : void 0;
      var history = context.history,
          staticContext = context.staticContext;
      var method = push ? history.push : history.replace;
      var location = createLocation(computedMatch ? typeof to === "string" ? generatePath(to, computedMatch.params) : _extends({}, to, {
        pathname: generatePath(to.pathname, computedMatch.params)
      }) : to); // When rendering in a static context,
      // set the new location immediately.

      if (staticContext) {
        method(location);
        return null;
      }

      return /*#__PURE__*/React__default.createElement(Lifecycle, {
        onMount: function onMount() {
          method(location);
        },
        onUpdate: function onUpdate(self, prevProps) {
          var prevLocation = createLocation(prevProps.to);

          if (!locationsAreEqual(prevLocation, _extends({}, location, {
            key: prevLocation.key
          }))) {
            method(location);
          }
        },
        to: to
      });
    });
  }

  {
    Redirect.propTypes = {
      push: propTypes.bool,
      from: propTypes.string,
      to: propTypes.oneOfType([propTypes.string, propTypes.object]).isRequired
    };
  }

  var cache$1 = {};
  var cacheLimit$1 = 10000;
  var cacheCount$1 = 0;

  function compilePath$1(path, options) {
    var cacheKey = "" + options.end + options.strict + options.sensitive;
    var pathCache = cache$1[cacheKey] || (cache$1[cacheKey] = {});
    if (pathCache[path]) return pathCache[path];
    var keys = [];
    var regexp = pathToRegexp_1(path, keys, options);
    var result = {
      regexp: regexp,
      keys: keys
    };

    if (cacheCount$1 < cacheLimit$1) {
      pathCache[path] = result;
      cacheCount$1++;
    }

    return result;
  }
  /**
   * Public API for matching a URL pathname to a path.
   */


  function matchPath(pathname, options) {
    if (options === void 0) {
      options = {};
    }

    if (typeof options === "string" || Array.isArray(options)) {
      options = {
        path: options
      };
    }

    var _options = options,
        path = _options.path,
        _options$exact = _options.exact,
        exact = _options$exact === void 0 ? false : _options$exact,
        _options$strict = _options.strict,
        strict = _options$strict === void 0 ? false : _options$strict,
        _options$sensitive = _options.sensitive,
        sensitive = _options$sensitive === void 0 ? false : _options$sensitive;
    var paths = [].concat(path);
    return paths.reduce(function (matched, path) {
      if (!path && path !== "") return null;
      if (matched) return matched;

      var _compilePath = compilePath$1(path, {
        end: exact,
        strict: strict,
        sensitive: sensitive
      }),
          regexp = _compilePath.regexp,
          keys = _compilePath.keys;

      var match = regexp.exec(pathname);
      if (!match) return null;
      var url = match[0],
          values = match.slice(1);
      var isExact = pathname === url;
      if (exact && !isExact) return null;
      return {
        path: path,
        // the path used to match
        url: path === "/" && url === "" ? "/" : url,
        // the matched portion of the URL
        isExact: isExact,
        // whether or not we matched exactly
        params: keys.reduce(function (memo, key, index) {
          memo[key.name] = values[index];
          return memo;
        }, {})
      };
    }, null);
  }

  function isEmptyChildren(children) {
    return React__default.Children.count(children) === 0;
  }

  function evalChildrenDev(children, props, path) {
    var value = children(props);
     warning(value !== undefined, "You returned `undefined` from the `children` function of " + ("<Route" + (path ? " path=\"" + path + "\"" : "") + ">, but you ") + "should have returned a React element or `null`") ;
    return value || null;
  }
  /**
   * The public API for matching a single path and rendering.
   */


  var Route = /*#__PURE__*/function (_React$Component) {
    _inheritsLoose(Route, _React$Component);

    function Route() {
      return _React$Component.apply(this, arguments) || this;
    }

    var _proto = Route.prototype;

    _proto.render = function render() {
      var _this = this;

      return /*#__PURE__*/React__default.createElement(context.Consumer, null, function (context$1) {
        !context$1 ?  invariant(false, "You should not use <Route> outside a <Router>")  : void 0;
        var location = _this.props.location || context$1.location;
        var match = _this.props.computedMatch ? _this.props.computedMatch // <Switch> already computed the match for us
        : _this.props.path ? matchPath(location.pathname, _this.props) : context$1.match;

        var props = _extends({}, context$1, {
          location: location,
          match: match
        });

        var _this$props = _this.props,
            children = _this$props.children,
            component = _this$props.component,
            render = _this$props.render; // Preact uses an empty array as children by
        // default, so use null if that's the case.

        if (Array.isArray(children) && isEmptyChildren(children)) {
          children = null;
        }

        return /*#__PURE__*/React__default.createElement(context.Provider, {
          value: props
        }, props.match ? children ? typeof children === "function" ?  evalChildrenDev(children, props, _this.props.path)  : children : component ? /*#__PURE__*/React__default.createElement(component, props) : render ? render(props) : null : typeof children === "function" ?  evalChildrenDev(children, props, _this.props.path)  : null);
      });
    };

    return Route;
  }(React__default.Component);

  {
    Route.propTypes = {
      children: propTypes.oneOfType([propTypes.func, propTypes.node]),
      component: function component(props, propName) {
        if (props[propName] && !reactIs_1(props[propName])) {
          return new Error("Invalid prop 'component' supplied to 'Route': the prop is not a valid React component");
        }
      },
      exact: propTypes.bool,
      location: propTypes.object,
      path: propTypes.oneOfType([propTypes.string, propTypes.arrayOf(propTypes.string)]),
      render: propTypes.func,
      sensitive: propTypes.bool,
      strict: propTypes.bool
    };

    Route.prototype.componentDidMount = function () {
       warning(!(this.props.children && !isEmptyChildren(this.props.children) && this.props.component), "You should not use <Route component> and <Route children> in the same route; <Route component> will be ignored") ;
       warning(!(this.props.children && !isEmptyChildren(this.props.children) && this.props.render), "You should not use <Route render> and <Route children> in the same route; <Route render> will be ignored") ;
       warning(!(this.props.component && this.props.render), "You should not use <Route component> and <Route render> in the same route; <Route render> will be ignored") ;
    };

    Route.prototype.componentDidUpdate = function (prevProps) {
       warning(!(this.props.location && !prevProps.location), '<Route> elements should not change from uncontrolled to controlled (or vice versa). You initially used no "location" prop and then provided one on a subsequent render.') ;
       warning(!(!this.props.location && prevProps.location), '<Route> elements should not change from controlled to uncontrolled (or vice versa). You provided a "location" prop initially but omitted it on a subsequent render.') ;
    };
  }

  function _objectWithoutPropertiesLoose(source, excluded) {
    if (source == null) return {};
    var target = {};
    var sourceKeys = Object.keys(source);
    var key, i;

    for (i = 0; i < sourceKeys.length; i++) {
      key = sourceKeys[i];
      if (excluded.indexOf(key) >= 0) continue;
      target[key] = source[key];
    }

    return target;
  }

  function addLeadingSlash(path) {
    return path.charAt(0) === "/" ? path : "/" + path;
  }

  function addBasename(basename, location) {
    if (!basename) return location;
    return _extends({}, location, {
      pathname: addLeadingSlash(basename) + location.pathname
    });
  }

  function stripBasename(basename, location) {
    if (!basename) return location;
    var base = addLeadingSlash(basename);
    if (location.pathname.indexOf(base) !== 0) return location;
    return _extends({}, location, {
      pathname: location.pathname.substr(base.length)
    });
  }

  function createURL(location) {
    return typeof location === "string" ? location : createPath(location);
  }

  function staticHandler(methodName) {
    return function () {
        invariant(false, "You cannot %s with <StaticRouter>")  ;
    };
  }

  function noop() {}
  /**
   * The public top-level API for a "static" <Router>, so-called because it
   * can't actually change the current location. Instead, it just records
   * location changes in a context object. Useful mainly in testing and
   * server-rendering scenarios.
   */


  var StaticRouter = /*#__PURE__*/function (_React$Component) {
    _inheritsLoose(StaticRouter, _React$Component);

    function StaticRouter() {
      var _this;

      for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
        args[_key] = arguments[_key];
      }

      _this = _React$Component.call.apply(_React$Component, [this].concat(args)) || this;

      _this.handlePush = function (location) {
        return _this.navigateTo(location, "PUSH");
      };

      _this.handleReplace = function (location) {
        return _this.navigateTo(location, "REPLACE");
      };

      _this.handleListen = function () {
        return noop;
      };

      _this.handleBlock = function () {
        return noop;
      };

      return _this;
    }

    var _proto = StaticRouter.prototype;

    _proto.navigateTo = function navigateTo(location, action) {
      var _this$props = this.props,
          _this$props$basename = _this$props.basename,
          basename = _this$props$basename === void 0 ? "" : _this$props$basename,
          _this$props$context = _this$props.context,
          context = _this$props$context === void 0 ? {} : _this$props$context;
      context.action = action;
      context.location = addBasename(basename, createLocation(location));
      context.url = createURL(context.location);
    };

    _proto.render = function render() {
      var _this$props2 = this.props,
          _this$props2$basename = _this$props2.basename,
          basename = _this$props2$basename === void 0 ? "" : _this$props2$basename,
          _this$props2$context = _this$props2.context,
          context = _this$props2$context === void 0 ? {} : _this$props2$context,
          _this$props2$location = _this$props2.location,
          location = _this$props2$location === void 0 ? "/" : _this$props2$location,
          rest = _objectWithoutPropertiesLoose(_this$props2, ["basename", "context", "location"]);

      var history = {
        createHref: function createHref(path) {
          return addLeadingSlash(basename + createURL(path));
        },
        action: "POP",
        location: stripBasename(basename, createLocation(location)),
        push: this.handlePush,
        replace: this.handleReplace,
        go: staticHandler(),
        goBack: staticHandler(),
        goForward: staticHandler(),
        listen: this.handleListen,
        block: this.handleBlock
      };
      return /*#__PURE__*/React__default.createElement(Router, _extends({}, rest, {
        history: history,
        staticContext: context
      }));
    };

    return StaticRouter;
  }(React__default.Component);

  {
    StaticRouter.propTypes = {
      basename: propTypes.string,
      context: propTypes.object,
      location: propTypes.oneOfType([propTypes.string, propTypes.object])
    };

    StaticRouter.prototype.componentDidMount = function () {
       warning(!this.props.history, "<StaticRouter> ignores the history prop. To use a custom history, " + "use `import { Router }` instead of `import { StaticRouter as Router }`.") ;
    };
  }

  /**
   * The public API for rendering the first <Route> that matches.
   */

  var Switch = /*#__PURE__*/function (_React$Component) {
    _inheritsLoose(Switch, _React$Component);

    function Switch() {
      return _React$Component.apply(this, arguments) || this;
    }

    var _proto = Switch.prototype;

    _proto.render = function render() {
      var _this = this;

      return /*#__PURE__*/React__default.createElement(context.Consumer, null, function (context) {
        !context ?  invariant(false, "You should not use <Switch> outside a <Router>")  : void 0;
        var location = _this.props.location || context.location;
        var element, match; // We use React.Children.forEach instead of React.Children.toArray().find()
        // here because toArray adds keys to all child elements and we do not want
        // to trigger an unmount/remount for two <Route>s that render the same
        // component at different URLs.

        React__default.Children.forEach(_this.props.children, function (child) {
          if (match == null && /*#__PURE__*/React__default.isValidElement(child)) {
            element = child;
            var path = child.props.path || child.props.from;
            match = path ? matchPath(location.pathname, _extends({}, child.props, {
              path: path
            })) : context.match;
          }
        });
        return match ? /*#__PURE__*/React__default.cloneElement(element, {
          location: location,
          computedMatch: match
        }) : null;
      });
    };

    return Switch;
  }(React__default.Component);

  {
    Switch.propTypes = {
      children: propTypes.node,
      location: propTypes.object
    };

    Switch.prototype.componentDidUpdate = function (prevProps) {
       warning(!(this.props.location && !prevProps.location), '<Switch> elements should not change from uncontrolled to controlled (or vice versa). You initially used no "location" prop and then provided one on a subsequent render.') ;
       warning(!(!this.props.location && prevProps.location), '<Switch> elements should not change from controlled to uncontrolled (or vice versa). You provided a "location" prop initially but omitted it on a subsequent render.') ;
    };
  }

  /**
   * Copyright 2015, Yahoo! Inc.
   * Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
   */

  var REACT_STATICS = {
      childContextTypes: true,
      contextType: true,
      contextTypes: true,
      defaultProps: true,
      displayName: true,
      getDefaultProps: true,
      getDerivedStateFromError: true,
      getDerivedStateFromProps: true,
      mixins: true,
      propTypes: true,
      type: true
  };

  var KNOWN_STATICS = {
      name: true,
      length: true,
      prototype: true,
      caller: true,
      callee: true,
      arguments: true,
      arity: true
  };

  var FORWARD_REF_STATICS = {
      '$$typeof': true,
      render: true,
      defaultProps: true,
      displayName: true,
      propTypes: true
  };

  var MEMO_STATICS = {
      '$$typeof': true,
      compare: true,
      defaultProps: true,
      displayName: true,
      propTypes: true,
      type: true
  };

  var TYPE_STATICS = {};
  TYPE_STATICS[reactIs.ForwardRef] = FORWARD_REF_STATICS;

  function getStatics(component) {
      if (reactIs.isMemo(component)) {
          return MEMO_STATICS;
      }
      return TYPE_STATICS[component['$$typeof']] || REACT_STATICS;
  }

  var defineProperty = Object.defineProperty;
  var getOwnPropertyNames = Object.getOwnPropertyNames;
  var getOwnPropertySymbols$1 = Object.getOwnPropertySymbols;
  var getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
  var getPrototypeOf = Object.getPrototypeOf;
  var objectPrototype = Object.prototype;

  function hoistNonReactStatics(targetComponent, sourceComponent, blacklist) {
      if (typeof sourceComponent !== 'string') {
          // don't hoist over string (html) components

          if (objectPrototype) {
              var inheritedComponent = getPrototypeOf(sourceComponent);
              if (inheritedComponent && inheritedComponent !== objectPrototype) {
                  hoistNonReactStatics(targetComponent, inheritedComponent, blacklist);
              }
          }

          var keys = getOwnPropertyNames(sourceComponent);

          if (getOwnPropertySymbols$1) {
              keys = keys.concat(getOwnPropertySymbols$1(sourceComponent));
          }

          var targetStatics = getStatics(targetComponent);
          var sourceStatics = getStatics(sourceComponent);

          for (var i = 0; i < keys.length; ++i) {
              var key = keys[i];
              if (!KNOWN_STATICS[key] && !(blacklist && blacklist[key]) && !(sourceStatics && sourceStatics[key]) && !(targetStatics && targetStatics[key])) {
                  var descriptor = getOwnPropertyDescriptor(sourceComponent, key);
                  try {
                      // Avoid failures from read-only properties
                      defineProperty(targetComponent, key, descriptor);
                  } catch (e) {}
              }
          }

          return targetComponent;
      }

      return targetComponent;
  }

  var hoistNonReactStatics_cjs = hoistNonReactStatics;

  /**
   * A public higher-order component to access the imperative API
   */

  function withRouter(Component) {
    var displayName = "withRouter(" + (Component.displayName || Component.name) + ")";

    var C = function C(props) {
      var wrappedComponentRef = props.wrappedComponentRef,
          remainingProps = _objectWithoutPropertiesLoose(props, ["wrappedComponentRef"]);

      return /*#__PURE__*/React__default.createElement(context.Consumer, null, function (context) {
        !context ?  invariant(false, "You should not use <" + displayName + " /> outside a <Router>")  : void 0;
        return /*#__PURE__*/React__default.createElement(Component, _extends({}, remainingProps, context, {
          ref: wrappedComponentRef
        }));
      });
    };

    C.displayName = displayName;
    C.WrappedComponent = Component;

    {
      C.propTypes = {
        wrappedComponentRef: propTypes.oneOfType([propTypes.string, propTypes.func, propTypes.object])
      };
    }

    return hoistNonReactStatics_cjs(C, Component);
  }

  var useContext = React__default.useContext;
  function useHistory() {
    {
      !(typeof useContext === "function") ?  invariant(false, "You must use React >= 16.8 in order to use useHistory()")  : void 0;
    }

    return useContext(historyContext);
  }
  function useLocation() {
    {
      !(typeof useContext === "function") ?  invariant(false, "You must use React >= 16.8 in order to use useLocation()")  : void 0;
    }

    return useContext(context).location;
  }
  function useParams() {
    {
      !(typeof useContext === "function") ?  invariant(false, "You must use React >= 16.8 in order to use useParams()")  : void 0;
    }

    var match = useContext(context).match;
    return match ? match.params : {};
  }
  function useRouteMatch(path) {
    {
      !(typeof useContext === "function") ?  invariant(false, "You must use React >= 16.8 in order to use useRouteMatch()")  : void 0;
    }

    var location = useLocation();
    var match = useContext(context).match;
    return path ? matchPath(location.pathname, path) : match;
  }

  {
    if (typeof window !== "undefined") {
      var global$1 = window;
      var key = "__react_router_build__";
      var buildNames = {
        cjs: "CommonJS",
        esm: "ES modules",
        umd: "UMD"
      };

      if (global$1[key] && global$1[key] !== "umd") {
        var initialBuildName = buildNames[global$1[key]];
        var secondaryBuildName = buildNames["umd"]; // TODO: Add link to article that explains in detail how to avoid
        // loading 2 different builds.

        throw new Error("You are loading the " + secondaryBuildName + " build of React Router " + ("on a page that is already running the " + initialBuildName + " ") + "build, so things won't work right.");
      }

      global$1[key] = "umd";
    }
  }

  exports.MemoryRouter = MemoryRouter;
  exports.Prompt = Prompt;
  exports.Redirect = Redirect;
  exports.Route = Route;
  exports.Router = Router;
  exports.StaticRouter = StaticRouter;
  exports.Switch = Switch;
  exports.__HistoryContext = historyContext;
  exports.__RouterContext = context;
  exports.generatePath = generatePath;
  exports.matchPath = matchPath;
  exports.useHistory = useHistory;
  exports.useLocation = useLocation;
  exports.useParams = useParams;
  exports.useRouteMatch = useRouteMatch;
  exports.withRouter = withRouter;

  Object.defineProperty(exports, '__esModule', { value: true });

}));
//# sourceMappingURL=react-router.js.map