This paper introduces a new method of designing regular array algorithms (systolic or semisystolic, in particular) through the use of a dialect of FP language, aFP, which contains many desirable parallel constructs. An aFP program is first written to solve a given problem, and then mapped to a certain regular array structure systematically. We present not only mapping rules from aFP functions to regular array structures but also some various examples of array algorithm design. The aFP language is also very promising for compiling and executing systolic algorithms directly in a reconfigurable systolic system. #