He prefers a hybrid approach where there are "islands of purity" in an otherwise imperative language with a clear delineation between them.
It's hard to imagine programming languages without these characteristics because imperative languages' "tell me how to do it" approach is so firmly entrenched in our everyday programming philosophies.
The functional programming approach is easy to understand, but can be difficult to apply if you are used to the more procedural and state-focused imperative languages.
