> Every time we iterate over numbers, it will start over at the beginning of the iterator method and yield all the same values over again. (You can’t expect this from every iterator; more on that later.)
They never did, or did I miss it?
They never did, or did I miss it?
> An iterator could query a database, for example—including the unfortunate possibility that it might alter data, or that iterating through it twice might yield completely different results! Some tools (like ReSharper) will warn you against multiple enumeration for this reason.