Any Combine experts out there? Is the example on this page correct?

https://developer.apple.com/documentation/combine/publisher/zip(_:)

My naïve understanding would be that, as soon as I feed in an "A", it would output A1, but somehow it waits to output anything until *another* number is input?

Is that because it only checks for new values on the number publisher, and lettersPub has no clue it's being zipped?

#swiftlang #combine #publishers