1. A method performed by a compiler in a computer system, the method comprising: identifying a first nested communication operator that partitions a computational space in data parallel source code configured for execution on one or more data parallel optimal compute nodes having a special purpose architecture, the data parallel source code including data parallel features that take advantage of the special purpose architecture of the data parallel optimal compute nodes to allow data parallel operations to be executed faster or more efficiently than with general purpose processors; and generating data parallel executable code from the data parallel source code such that the data parallel executable code implements the first nested communication operator by generating an output indexable type that represents a plurality of segments of an input indexable type having a rank and an element, type defining the computational space.