react/packages/shared/ReactSymbols.js
Sebastian Markbåge 65bbda7f16
Rename Chunks API to Blocks (#18086)
Sounds like this is the name we're going with. This also helps us
distinguish it from other "chunking" implementation details.
2020-02-20 23:56:40 -08:00

78 lines
2.6 KiB
JavaScript

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
*/
// 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.
const hasSymbol = typeof Symbol === 'function' && Symbol.for;
export const REACT_ELEMENT_TYPE = hasSymbol
? Symbol.for('react.element')
: 0xeac7;
export const REACT_PORTAL_TYPE = hasSymbol
? Symbol.for('react.portal')
: 0xeaca;
export const REACT_FRAGMENT_TYPE = hasSymbol
? Symbol.for('react.fragment')
: 0xeacb;
export const REACT_STRICT_MODE_TYPE = hasSymbol
? Symbol.for('react.strict_mode')
: 0xeacc;
export const REACT_PROFILER_TYPE = hasSymbol
? Symbol.for('react.profiler')
: 0xead2;
export const REACT_PROVIDER_TYPE = hasSymbol
? Symbol.for('react.provider')
: 0xeacd;
export const 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?
export const REACT_ASYNC_MODE_TYPE = hasSymbol
? Symbol.for('react.async_mode')
: 0xeacf;
export const REACT_CONCURRENT_MODE_TYPE = hasSymbol
? Symbol.for('react.concurrent_mode')
: 0xeacf;
export const REACT_FORWARD_REF_TYPE = hasSymbol
? Symbol.for('react.forward_ref')
: 0xead0;
export const REACT_SUSPENSE_TYPE = hasSymbol
? Symbol.for('react.suspense')
: 0xead1;
export const REACT_SUSPENSE_LIST_TYPE = hasSymbol
? Symbol.for('react.suspense_list')
: 0xead8;
export const REACT_MEMO_TYPE = hasSymbol ? Symbol.for('react.memo') : 0xead3;
export const REACT_LAZY_TYPE = hasSymbol ? Symbol.for('react.lazy') : 0xead4;
export const REACT_BLOCK_TYPE = hasSymbol ? Symbol.for('react.block') : 0xead9;
export const REACT_FUNDAMENTAL_TYPE = hasSymbol
? Symbol.for('react.fundamental')
: 0xead5;
export const REACT_RESPONDER_TYPE = hasSymbol
? Symbol.for('react.responder')
: 0xead6;
export const REACT_SCOPE_TYPE = hasSymbol ? Symbol.for('react.scope') : 0xead7;
const MAYBE_ITERATOR_SYMBOL = typeof Symbol === 'function' && Symbol.iterator;
const FAUX_ITERATOR_SYMBOL = '@@iterator';
export function getIteratorFn(maybeIterable: ?any): ?() => ?Iterator<*> {
if (maybeIterable === null || typeof maybeIterable !== 'object') {
return null;
}
const maybeIterator =
(MAYBE_ITERATOR_SYMBOL && maybeIterable[MAYBE_ITERATOR_SYMBOL]) ||
maybeIterable[FAUX_ITERATOR_SYMBOL];
if (typeof maybeIterator === 'function') {
return maybeIterator;
}
return null;
}