src/vs/editor/contrib/inlineCompletions/browser/inlineCompletionToGhostText.ts/deletedCharacters
function deletedCharacters(changes: readonly IDiffChange[]): number {
	let sum = 0;
	for (const c of changes) {
		sum += Math.max(c.originalLength - c.modifiedLength, 0);
	}
	return sum;
}