loading race condition: `ReferenceError: cmView is not defined`

[cben]

When using the new LINE_COLUMN(), CALLER() etc. apis, they currently access cmView variable set in Editor component.

• EditEvalRenderLoop component triggers first code evaluation before Editor renders, so it's unset and crashes. User has to make an edit (any edit) for things to work.
• What if Editor re-renders, can callbacks refer to wrong view? Specifically after crash boundary?

model-view-self-modify/index.html

Lines 343 to 346 in 3211191

	const view = new EditorView({ state: startState, parent: editor.current })
	// TODO these execute after first code evaluation, so if editor code
	// references cmView or calls WRITE etc. directly, it fails after reload.
	window.cmView = view

1. I think next step is separate construction of source location proxies like LINE_COLUMN() from actions like .JUMP() or .WRITE(). The former can close over some higher EditEvalRenderLoop state (a ref? a promise?), only the latter should need a codemirror view.
2. And/or a kludge: delay evaluation until Editor rendered and set cmView?
   • Make it a promise? Make whole API ({ WRITE, CALLER, ... }) exposed to evaluation a promise?

[cben]

Kludge: deferring CURSOR() etc. resolution + using global cmView instead of anchors' this.cmView was sufficient for README.html to work on load 🎉

The underlying bug still lurks. This is a blocker for multi-Editor use.