说明：  PL/0语言是Pascal语言的一个子集，我们这里分析的PL/0的编译程序包括了对PL/0语言源程序进行分析处理、编译生成类PCODE代码，并在虚拟机上解释运行生成的类PCODE代码的功能。 　　PL/0语言编译程序采用以语法分析为核心、一遍扫描的编译方法。词法分析和代码生成作为独立的子程序供语法分析程序调用。语法分析的同时，提供了出错报告和出错恢复的功能。在源程序没有错误编译通过的情况下，调用类PCODE解释程序解释执行生成的类PCODE代码。以下源程序是以清华大学出版社《编译原理》中的源代码为基础作了少量改动而成。 程序在Turbo Pascal 7.0上编译运行通过。
(PL/0 language Pascal language is a subset of, we have here the analysis of PL/0 compilers including the right PL/0 language source analysis, category PCODE compiler code generation and the virtual machine running on to explain the formation PCODE category code functions. PL/0 language compiler to use syntax analysis of the core, the compiler again scanning methods. Lexical analysis, and code generation as an independent for the subroutine call syntax analysis procedures. Grammatical analysis at the same time, provided a report errors and error recovery functions. The source did not compile the wrong circumstances, PCODE category called to explain the interpretation and implementation of procedures generated PCODE category code. Following is the source Qinghua University Press, &quo)