Implicit Communication in Programming Languages by Declaration, Reference, and Assignment

With the increase of communication between computers, we need techniques for (i) communication to be handled automatically or implicitly, and (ii) flexible programs capable of handling data from different kinds of correspondents with no reprogramming. The traditional approach of handling input/output, files, inter program communication and man machine interfaces by specific statements in programming languages restricts these two aims. We propose handling these activities implicitly and in a unified manner by separating a program into a pure algorithm with no communication statements (PurAL), and separate declarations which describe externally mapped variables (DUAL description). So, without using I/O or communication statements, just assigning to an externally mapped variable will cause a value to be sent outside the program. Similarly referencing such a variable will cause a value to be fetched from outside the program (if it has not been fetched already). As the mapping of variables is described separately from the program, this enables the program to be used in various contexts (ports, files, networks, windows etc.). By specifying that a variable is mapped to data on another computer, in effect we are dealing with remote data access, i.e. the communication is implicit. By specifying that an output-variable in one program is to be mapped to input-variables in other programs, we have in effect a generalization of the pipe and tee operating system constructs. We also propose heuristics for open/close and lock/unlock, enabling these operations to be carried out automatically.