[Fiber] Child Reconciler + New Coroutines Primitive

src/isomorphic/classic/element/ReactElement.js

@@ -398,4 +398,6 @@ ReactElement.isValidElement = function(object) {
   );
 };
 
+ReactElement.REACT_ELEMENT_TYPE = REACT_ELEMENT_TYPE;
+
 module.exports = ReactElement;

src/isomorphic/classic/element/ReactElementValidator.js

@@ -184,7 +184,8 @@ function validatePropTypes(element) {
 var ReactElementValidator = {
 
   createElement: function(type, props, children) {
-    var validType = typeof type === 'string' || typeof type === 'function';
+    var validType = typeof type === 'string' || typeof type === 'function' ||
+                    (type !== null && typeof type === 'object');
     // We warn in this case but don't throw. We expect the element creation to
     // succeed and there will likely be errors in render.
     warning(

src/renderers/noop/__tests__/ReactNoop-test.js

@@ -13,11 +13,14 @@
 
 var React;
 var ReactNoop;
+var ReactCoroutine;
 
 describe('ReactComponent', function() {
   beforeEach(function() {
     React = require('React');
     ReactNoop = require('ReactNoop');
+    ReactCoroutine = require('ReactCoroutine');
+    spyOn(console, 'log');
   });
 
   it('should render a simple component', function() {
@@ -38,11 +41,14 @@ describe('ReactComponent', function() {
   it('should render a simple component, in steps if needed', function() {
 
     function Bar() {
-      return <div>Hello World</div>;
+      return <span><div>Hello World</div></span>;
     }
 
     function Foo() {
-      return <Bar isBar={true} />;
+      return [
+        <Bar isBar={true} />,
+        <Bar isBar={true} />,
+      ];
     }
 
     ReactNoop.render(<Foo />);
@@ -53,5 +59,47 @@ describe('ReactComponent', function() {
     // console.log('Done');
   });
 
+  it('should render a coroutine', function() {
+
+    function Continuation({ isSame }) {
+      return <span>{isSame ? 'foo==bar' : 'foo!=bar'}</span>;
+    }
+
+    // An alternative API could mark Continuation as something that needs
+    // yielding. E.g. Continuation.yieldType = 123;
+    function Child({ bar }) {
+      return ReactCoroutine.createYield({
+        bar: bar,
+      }, Continuation, null);
+    }
+
+    function Indirection() {
+      return [<Child bar={true} />, <Child bar={false} />];
+    }
+
+    function HandleYields(props, yields) {
+      return yields.map(y =>
+        <y.continuation isSame={props.foo === y.props.bar} />
+      );
+    }
+
+    // An alternative API could mark Parent as something that needs
+    // yielding. E.g. Parent.handler = HandleYields;
+    function Parent(props) {
+      return ReactCoroutine.createCoroutine(
+        props.children,
+        HandleYields,
+        props
+      );
+    }
+
+    function App() {
+      return <div><Parent foo={true}><Indirection /></Parent></div>;
+    }
+
+    ReactNoop.render(<App />);
+    ReactNoop.flush();
+
+  });
 
 });

src/renderers/shared/fiber/ReactChildFiber.js

@@ -0,0 +1,129 @@
+/**
+ * Copyright 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule ReactChildFiber
+ * @flow
+ */
+
+'use strict';
+
+import type { ReactCoroutine, ReactYield } from 'ReactCoroutine';
+import type { Fiber } from 'ReactFiber';
+
+import type { ReactNodeList } from 'ReactTypes';
+
+var {
+  REACT_ELEMENT_TYPE,
+} = require('ReactElement');
+var {
+  REACT_COROUTINE_TYPE,
+  REACT_YIELD_TYPE,
+} = require('ReactCoroutine');
+
+var ReactFiber = require('ReactFiber');
+var ReactReifiedYield = require('ReactReifiedYield');
+
+function createSubsequentChild(parent : Fiber, previousSibling : Fiber, newChildren) : Fiber {
+  if (typeof newChildren !== 'object' || newChildren === null) {
+    return previousSibling;
+  }
+
+  switch (newChildren.$$typeof) {
+    case REACT_ELEMENT_TYPE: {
+      const element = (newChildren : ReactElement);
+      const child = ReactFiber.createFiberFromElement(element);
+      previousSibling.sibling = child;
+      child.parent = parent;
+      return child;
+    }
+
+    case REACT_COROUTINE_TYPE: {
+      const coroutine = (newChildren : ReactCoroutine);
+      const child = ReactFiber.createFiberFromCoroutine(coroutine);
+      previousSibling.sibling = child;
+      child.parent = parent;
+      return child;
+    }
+
+    case REACT_YIELD_TYPE: {
+      const yieldNode = (newChildren : ReactYield);
+      const reifiedYield = ReactReifiedYield.createReifiedYield(yieldNode);
+      const child = ReactFiber.createFiberFromYield(yieldNode);
+      child.output = reifiedYield;
+      previousSibling.sibling = child;
+      child.parent = parent;
+      return child;
+    }
+  }
+
+  if (Array.isArray(newChildren)) {
+    let prev : Fiber = previousSibling;
+    for (var i = 0; i < newChildren.length; i++) {
+      prev = createSubsequentChild(parent, prev, newChildren[i]);
+    }
+    return prev;
+  } else {
+    console.log('Unknown child', newChildren);
+    return previousSibling;
+  }
+}
+
+function createFirstChild(parent, newChildren) {
+  if (typeof newChildren !== 'object' || newChildren === null) {
+    return null;
+  }
+
+  switch (newChildren.$$typeof) {
+    case REACT_ELEMENT_TYPE: {
+      const element = (newChildren : ReactElement);
+      const child = ReactFiber.createFiberFromElement(element);
+      child.parent = parent;
+      return child;
+    }
+
+    case REACT_COROUTINE_TYPE: {
+      const coroutine = (newChildren : ReactCoroutine);
+      const child = ReactFiber.createFiberFromCoroutine(coroutine);
+      child.parent = parent;
+      return child;
+    }
+
+    case REACT_YIELD_TYPE: {
+      // A yield results in a fragment fiber whose output is the continuation.
+      // TODO: When there is only a single child, we can optimize this to avoid
+      // the fragment.
+      const yieldNode = (newChildren : ReactYield);
+      const reifiedYield = ReactReifiedYield.createReifiedYield(yieldNode);
+      const child = ReactFiber.createFiberFromYield(yieldNode);
+      child.output = reifiedYield;
+      child.parent = parent;
+      return child;
+    }
+  }
+
+  if (Array.isArray(newChildren)) {
+    var first : ?Fiber = null;
+    var prev : ?Fiber = null;
+    for (var i = 0; i < newChildren.length; i++) {
+      if (prev == null) {
+        prev = createFirstChild(parent, newChildren[i]);
+        first = prev;
+      } else {
+        prev = createSubsequentChild(parent, prev, newChildren[i]);
+      }
+    }
+    return first;
+  } else {
+    console.log('Unknown child', newChildren);
+    return null;
+  }
+}
+
+exports.reconcileChildFibers = function(parent : Fiber, firstChild : ?Fiber, newChildren : ReactNodeList) : ?Fiber {
+  return createFirstChild(parent, newChildren);
+};

src/renderers/shared/fiber/ReactFiber.js

@@ -12,31 +12,47 @@
 
 'use strict';
 
-type StateNode = {};
-type EffectHandler = () => void;
-type EffectTag = number;
+var ReactTypesOfWork = require('ReactTypesOfWork');
+var {
+  IndeterminateComponent,
+  ClassComponent,
+  HostComponent,
+  CoroutineComponent,
+  YieldComponent,
+} = ReactTypesOfWork;
+
+var ReactElement = require('ReactElement');
+
+import type { ReactCoroutine, ReactYield } from 'ReactCoroutine';
 
 export type Fiber = {
 
+  // Tag identifying the type of fiber.
   tag: number,
 
-  parent: ?Fiber,
+  // Singly Linked List Tree Structure.
+  parent: ?Fiber, // Consider a regenerated temporary parent stack instead.
   child: ?Fiber,
   sibling: ?Fiber,
 
-  input: ?Object,
-  output: ?Object,
+  // Input is the data coming into process this fiber. Arguments.
+  input: any, // This type will be more specific once we overload the tag.
+  // Output is the return value of this fiber, or a linked list of return values
+  // if this returns multiple values. Such as a fragment.
+  output: any, // This type will be more specific once we overload the tag.
 
-  handler: EffectHandler,
-  handlerTag: EffectTag,
+  // Used by multi-stage coroutines.
+  stage: number, // Consider reusing the tag field instead.
 
+  // This will be used to quickly determine if a subtree has no pending changes.
   hasPendingChanges: bool,
 
-  stateNode: StateNode,
+  // The local state associated with this fiber.
+  stateNode: ?Object,
 
 };
 
-module.exports = function(tag : number) : Fiber {
+var createFiber = function(tag : number) : Fiber {
   return {
 
     tag: tag,
@@ -48,12 +64,53 @@ module.exports = function(tag : number) : Fiber {
     input: null,
     output: null,
 
-    handler: function() {},
-    handlerTag: 0,
+    stage: 0,
 
     hasPendingChanges: true,
 
-    stateNode: {},
+    stateNode: null,
 
   };
 };
+
+function shouldConstruct(Component) {
+  return !!(Component.prototype && Component.prototype.isReactComponent);
+}
+
+exports.createFiberFromElement = function(element : ReactElement) {
+  const fiber = exports.createFiberFromElementType(element.type);
+  if (typeof element.type === 'object') {
+    // Hacky McHack
+    element = ReactElement(fiber.input, null, element.ref, null, null, null, element.props);
+  }
+  fiber.input = element;
+  return fiber;
+};
+
+exports.createFiberFromElementType = function(type : mixed) {
+  let fiber;
+  if (typeof type === 'function') {
+    fiber = shouldConstruct(type) ?
+      createFiber(ClassComponent) :
+      createFiber(IndeterminateComponent);
+  } else if (typeof type === 'string') {
+    fiber = createFiber(HostComponent);
+  } else if (typeof type === 'object' && type !== null) {
+    // Currently assumed to be a continuation and therefore is a fiber already.
+    fiber = type;
+  } else {
+    throw new Error('Unknown component type: ' + typeof type);
+  }
+  return fiber;
+};
+
+exports.createFiberFromCoroutine = function(coroutine : ReactCoroutine) {
+  const fiber = createFiber(CoroutineComponent);
+  fiber.input = coroutine;
+  return fiber;
+};
+
+exports.createFiberFromYield = function(yieldNode : ReactYield) {
+  const fiber = createFiber(YieldComponent);
+  return fiber;
+};