编译原理实验报告-词法分析程序的设计与实现等.docxVIP

编译原理实验报告学???号：姓???名：提交日期：2016-11-29成???绩：东北大学秦皇岛分校计算机与通信工程学院实验一 词法分析程序的设计与实现一．实验内容【实验目的和要求】设计、编制、调试一个具体的词法分析程序，加深对词法分析原理的理解。【实验内容】通过对PL/0词法分析程序（GETSYM）的分析，并在此基础上按照附录A中给出的PL/0语言的语法描述，编写一个PL/0语言的词法分析程序。此程序应具有如下功能：输入为字符串（待进行词法分析的源程序），输出为单词串，即由（单词、类别）所组成的二元组序列。有一定检查错误的能力，例如发现2A这类不能作为单词的字符串。【实验环境】Windows PC机，任何语言。【提交内容】提交实验报告，报告内容如下：目的要求、算法描述、程序结构、主要变量名说明、程序清单、调试情况、设计技巧、心得体会。提交源程序和可执行文件。程序代码：Packagelexical;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.Reader;@SuppressWarnings(unused)publicclass a {staticpublic Reader reader = null;staticpublic String[] keyWords = { if, else, for, while, do,return, break, continue };staticpublic String[] borders = { ,, ;, {, }, (, ) };staticpublic String[] arithmetic = { +, -, *, / };staticpublic String[] relation1 = { , =, };staticpublic String[] relation2 = { =, =, };staticpublicbooleanisOver = false;staticprivatechar alphaprocess(char buffer) throws Exception {int i = -1;StringBuffer sb = new StringBuffer();char temp = buffer;while (Character.isLetter(temp) || Character.isDigit(temp)) {sb.append(temp);if((temp = (char) reader.read()) == -1) {isOver = true;}}if(!search(sb.toString(), 1)){search(sb.toString(),2);}return temp;}staticprivatechar digitprocess(char buffer) throws Exception {StringBuffer sb = new StringBuffer();char temp = buffer;while(Character.isDigit(temp)){sb.append(temp);if((temp = (char) reader.read()) == -1) {isOver = true;}}//数字后输入字母if(Character.isLetter(temp)){search(sb.toString(), 8);}else{search(sb.toString(), 3);}return temp;}staticprivatechar otherprocess(char buffer) throws Exception {StringBuffer sb = new StringBuffer();char temp = buffer;sb.append(temp);if((temp = (char) reader.read()) == -1) {isOver = true;}if(search(sb.toString(), 4)){return temp;}elseif(search(sb.toString(), 5)){return temp;}elseif(search(sb.toString(), 6)){return temp;}sb.append(temp);if(search(sb.toString(), 7)){if((temp = (char) reader.read()) == -1) {isOver = true;}}return