[StillBored]

And many languages, have parallel for constructs. The openmp #pragma parallel extensions in C/C++ for example. Of course its possible to create constructs which provide the messages passing for clustered environments too.

And maybe that is part of the problem with a generic 'map' your not really sure the underlying implementation, is it parallel, clustered, serial, etc? So you end up with map(), parallel_map(), mpi_map(), etc, and how to you control the parallelism. Do you just let it default or do you have levers to control the batch & interleave. Pretty soon, its not such a simple construct anymore.

[WoodTree]

In a functional language those details should be irrelevant. But of course they are relevant in practice, and map is usually just a for loop.