利用状态表和有限自动机的运行原理编制程序，使得程序能够识别一个输入串是否为一个有效的符号串，具体可以选择下面之一：无符号定点实数、自然数、整数、十六进制数或其它自己定义的符号串。-The use of state tables and finite automata operating principle of the production process to make the procedures to identify whether or not an input string for an effective symbol string, the specific can choose one of the following: unsigned fixed-point real numbers, natural numbers, integers, hexadecimal, or Other symbols string their own definitions.