akes in a type (a string representing the element type), props (an object of element properties), and children (an array of child elements or text nodes). It returns an object representing the element. If the child is not an element, it is converted to a text node using the createTextElement function.
The render function takes an element and a container as arguments and sets up the Fiber tree with a wipRoot object that holds the root element, its properties, and its children. It also sets the nextUnitOfWork to the wipRoot, which will start the rendering process.
The performUnitOfWork function takes a fiber and either updates its properties or creates new elements if it's the first time the fiber is being processed. It then returns the next fiber to be processed, starting from the first child, then the next sibling, and finally the parent.
The workLoop function runs continuously until there are no more units of work to perform. It uses requestIdleCallback to schedule itself to run when the browser is idle. Each iteration of the loop processes a single fiber using the performUnitOfWork function, which updates the DOM by creating new elements, updating existing ones, and deleting old ones. When the loop is finished, it commits the changes to the DOM with the commitRoot function.
The reconcileChildren function takes a wipFiber and an array of elements as arguments and iterates over them, comparing the old fiber to the new element and updating it if they have the same type. If the old fiber doesn't exist or has a different type, it creates a new fiber with the element and sets its effectTag to PLACEMENT. If the old fiber exists but has a different type, it sets its effectTag to DELETION, which will be handled by the commitWork function. If the old fiber exists and has the same type, it updates its properties and sets its effectTag to UPDATE.
The updateFunctionComponent function calls the function component with its props and returns the next fiber to be processed, starting with the first child.
