Влад Афонин

function getCursorPosition(parent) {
	let selection = document.getSelection()
	let range = new Range
	range.setStart(parent, 0)
	range.setEnd(selection.anchorNode, selection.anchorOffset)
	return range.toString().length
}

function setCursorPosition(parent, position) {
	let child = parent.firstChild
	while(position > 0) {
		let length = child.textContent.length
		if(position > length) {
			position -= length
			child = child.nextSibling
		}
		else {
			if(child.nodeType == 3) return document.getSelection().collapse(child, position)
			child = child.firstChild
		}
	}
}