/* */

/* eslint-disable no-bitwise, no-cond-assign */

/* eslint-disable no-return-assign */

/* harmony default export */

/* harmony export (binding) */

/* harmony import */

/*!
  Copyright (c) 2017 Jed Watson.
  Licensed under the MIT License (MIT), see
  http://jedwatson.github.io/classnames
*/

/*#__PURE__*/

/**
 * A convenience hook around `useState` designed to be paired with
 * the component [callback ref](https://reactjs.org/docs/refs-and-the-dom.html#callback-refs) api.
 * Callback refs are useful over `useRef()` when you need to respond to the ref being set
 * instead of lazily accessing it in an effect.
 *
 * ```ts
 * const [element, attachRef] = useCallbackRef<HTMLDivElement>()
 *
 * useEffect(() => {
 *   if (!element) return
 *
 *   const calendar = new FullCalendar.Calendar(element)
 *
 *   return () => {
 *     calendar.destroy()
 *   }
 * }, [element])
 *
 * return <div ref={attachRef} />
 * ```
 *
 * @category refs
 */

/**
 * An `addEventListener` ponyfill, supports the `once` option
 */

/**
 * Copyright 2013-2014, Facebook, Inc.
 * All rights reserved.
 * https://github.com/facebook/react/blob/2aeb8a2a6beb00617a4217f7f8284924fa2ad819/src/vendor/core/hyphenateStyleName.js
 */

/**
 * Creates a `Ref` whose value is updated in an effect, ensuring the most recent
 * value is the one rendered with. Generally only required for Concurrent mode usage
 * where previous work in `render()` may be discarded befor being used.
 *
 * This is safe to access in an event handler.
 *
 * @param value The `Ref` value
 */

/**
 * Store the last of some value. Tracked via a `Ref` only updating it
 * after the component renders.
 *
 * Helpful if you need to compare a prop value to it's previous value during render.
 *
 * ```ts
 * function Component(props) {
 *   const lastProps = usePrevious(props)
 *
 *   if (lastProps.foo !== props.foo)
 *     resetValueFromProps(props.foo)
 * }
 * ```
 *
 * @param value the value to track
 */

/**
 * Track whether a component is current mounted. Generally less preferable than
 * properlly canceling effects so they don't run after a component is unmounted,
 * but helpful in cases where that isn't feasible, such as a `Promise` resolution.
 *
 * @returns a function that returns the current isMounted state of the component
 *
 * ```ts
 * const [data, setData] = useState(null)
 * const isMounted = useMounted()
 *
 * useEffect(() => {
 *   fetchdata().then((newData) => {
 *      if (isMounted()) {
 *        setData(newData);
 *      }
 *   })
 * })
 * ```
 */

/**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

/**
* Square root of double-precision floating-point epsilon.
*
* @module @stdlib/constants/math/float64-sqrt-eps
* @type {number}
*
* @example
* var FLOAT64_SQRT_EPSILON = require( '@stdlib/constants/math/float64-sqrt-eps' );
* // returns 0.14901161193847656e-7
*/

/**
* Square root of double-precision floating-point epsilon.
*
* ```tex
* \sqrt{\frac{1}{2^{52}}}
* ```
*
* @constant
* @type {number}
* @default 0.14901161193847656e-7
* @see [IEEE 754]{@link https://en.wikipedia.org/wiki/IEEE_754-1985}
* @see [Machine Epsilon]{@link https://en.wikipedia.org/wiki/Machine_epsilon}
*/

/***/

//         nextStatus = ENTERING

//         nextStatus = EXITING

//       if (status !== ENTERING && status !== ENTERED) {

//       if (status === ENTERING || status === ENTERED) {

//       }

//     const { status } = this.state

//     if (this.props.in) {

//     }

//     } else {

//   if (prevProps !== this.props) {

//   let nextStatus = null

//   return { nextStatus }

//   }

// .toUpperCase handles XHTML

// Bypass onClick if it was present

// EXPORTS //

// HTML DOM and SVG DOM may have different support levels,

// IE 11

// In the context of a TransitionGroup all enters are really appears

// MAIN //

// Name the function so it is clearer in the documentation

// TODO: remove fallback for next major

// This shouldn't be necessary, but there are weird race conditions with

// all other browsers

// allows for nested Transitions

// do not inherit user-select (it may be `none`)

// eslint-disable-next-line @typescript-eslint/no-unused-expressions

// eslint-disable-next-line no-multi-assign

// getSnapshotBeforeUpdate(prevProps) {

// if we are mounting and running this it means appear _must_ be set

// nextStatus will always be ENTERING or EXITING.

// no enter animation skip right to ENTERED

// no exit animation skip right to EXITED

// prevents scrolling to the end of the page

// reading a dimension prop will cause the browser to recalculate,

// reset user styles for span element

// setState callbacks and unmounting in testing, so always make sure that

// so we need to check on context instead of a document root element.

// used to preserve spaces and line breaks

// we can cancel any pending setState callbacks after we unmount.

// which will let our animations work

// }
