Gdel语言控制机制的研究与实现

Research and implementation of the control facility of Gdel language

Gdel语言是在Prolog语言基础上发展而来的一种新型逻辑程序设计语言,而控制机制是逻辑程序设计语言的核心内容.针对Prolog语言控制机制存在的问题,引出了Gdel语言中新的控制机制,包括DELAY延迟机制和剪枝操作然后通过实例分析,表明了这些新机制能有效地避免递归谓词的低效或无限循环调用,并能够实现子目标的协同执行,从而提高系统的运行效率.针对这一有效改进,在对Gdel语言控制机制比较深入研究的基础上,最后给出了Gdel语言控制机制的实现算法.该算法已在研发的Gdel语言编译系统中得以实现,通过实例测试,验证了算法具有较高的效率.

Godel, a new logic programming language that emerged from Prolog, has at its core a control facility. After an analysis of problems with the control facility in Prolog, the authors proposed new control facilities for Godel which include a ＇ delay computing＇ and a ＇ pruning＇ operation. Examples showed that adoption of the new facilities effectively prevents inefficient or infinite loop calling of a recursive predicate and allows coroutining between subformulas, so that the efficiency of the system is considerably improved. Furthermore, an algorithm was proposed that could provide the control facility in Godel. The algorithm was applied in the Godel compiler developed by our group. The high efficiency of the algorithm was verified through testing.