Comment by antonvs

Traditional FP has had functional equivalents to iterators since before most imperative languages existed. LISP had a map function (MAPCAR) in its earliest versions, in the 1950s. Later that was generalized to folds, and the underlying structures were generalized from linked lists to arbitrary “traversable” types, including unbounded streams.

The language in the OP is a special-purpose language for data parallelism, targeting GPUs, and explicitly described as “not intended to replace existing general-purpose languages” (quote from the language’s home page.) As such, it has requirements and constraints that most languages don’t have. Looking at its design through a general-purpose languages lens doesn’t necessarily make sense.