A Study on a Direct Transformation System of Natural Specification into Executable Program

该项目的主要目标是建立一个自然和灵活的软件开发/维护环境，在这个环境中，应用系统的易于理解的图表规范可以直接转换为基于动态数据驱动方案的高度并行的可执行程序。本项目取得的成果总结如下：1。为实现系统功能、行为和数据结构的自然表示，建立了多边图解规范方案。在该环境中，表示功能块之间数据依赖关系的图形描述等框图直接转换为可执行的数据驱动程序，保留目标系统的处理结构。包含用于转换的附加基本信息的行为和数据结构也由图表形式表示。例如增广序列图、数据结构图、状态转换图和决策表。一个包含历史敏感过程和标记流的增强型动态数据驱动处理模型被证明是最有前途的原理，在该原理下，直接从图表规范生成的抽象程序以高度并行的方式解释，没有任何副作用。通过引入一种基于面向数据方法的通用实现方式，在工程工作站上建立了一个原型系统。在原型中，单片数据驱动处理器的可执行程序是直接从交互式环境中的图解规范生成的。通过评估几个实时应用的规范过程，例如电梯控制系统和MUSE信号解码器，证明了所提出系统的实用性。

The main objective of this project is to establish a natural and flexible software development/maintenance environment in which easily understandable diagrammatic specifications for appli-cation systems are directly transformed into highly-parallel executable programs based upon the dynamic data-driven scheme. The results obtained in the project are summarized as following :1.Multilateral diagrammatic specification scheme was established for natural representation of system function, behavior and data-structures. In the environment, a block diagram like graphical descriptions representing data dependencies among functional blocks are directly transformed into executable data-driven programs preserving the processing structures of target systems. Behavior and data structures which contain additional essential information for transformation are also represented by diagrammatic forms. e.g. augmented sequence charts, data-structure diagrams, state transition diagrams and decision tables.2.An augmented dynamic data-driven processing model incorporating history-sensitive processes and streams of tokens was proved to be the most promising principle under which the abstract pro-grams directly generated from the diagrammatic specifications are interpreted in a highly-parallel fashion without any side-effects.3.A prototype system were built on an engineering workstation by introducing a generic imple-mentation style based on the data oriented approach. In the prototype, executable programs for a single chip data-driven processor are directly generated from the diagrammatic specifications in an interactive environment.Practicability of the proposed system was demonstrated through evaluating specification process for several real-time applications, e.g. a lift control system and a MUSE signal decoder.