冶金热力学数据库应用系统怎样检查用户命令

Checking of User's Commands in METHEDAS

摘要: 本文介绍了METHEDAS怎样检查用户命令。根据用户命令的语法结构,对其进行三方面检查:
(1)命令关键字及格式。
(2)参数关键字及格式,参数的数据类型。
(3)命令与参数的搭配关系。
上述任务由用户命令解释程序的换码模块和语法检查模块完成。
METHEDAS的用户命令解释程序用FORTRAN-Ⅳ实现。它简单、实用、便于移植。在编制程序过程中较好地模拟了FORTRAN77的字符处理功能。

Abstract: Checking of user's commands in METHEDAS is the main subject in this paper.On basis of the syntactic structures of user's commands, the checking on following items:
1. command keywords and formats
2. parameter keywords, formats and their data types
3. rules of jointing commands with parameters
is completed by means of a code conversion module and a syntax parsing module, which compose an interpreter.
This interpreter, constructed within the FORTRAN-4 framework, is very successful in its simplicity, usefulness, and ability of simulating the string processing function, possessed by FORTRAN-77.