2023年西安邮电大学编译原理词法分析

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1、 西 安 邮 电 大 学 （计算机学院）课内实验报告实验名称： 词法分析器 专业名称：班 级： 学生姓名：学号（8位）：指导教师：实验日期： 年月日一. 实验目的及实验环境设计一个词法分析器，并更好的理解词法分析实现原理，掌握程序设计语言中各类单词的词法分析方法，并实现对一种程序设计语言的词法分析。二. 实验内容1.对java程序语言的词法分析：单词分类表：keyvaluetypekeyvaluetype1abstractKEYWORD42throwKEYWORD2assertKEYWORD43throwsKEYWORD3booleanKEYWORD44transientKEYWORD4bre

2、akKEYWORD45tryKEYWORD5caseKEYWORD46voidKEYWORD6catchKEYWORD47volatileKEYWORD7charKEYWORD48whileKEYWORD8classKEYWORD49+OPERATOR9constKEYWORD50+OPERATOR10continueKEYWORD51-OPERATOR11defaultKEYWORD52-OPERATOR12doKEYWORD53*OPERATOR13doubleKEYWORD54/OPERATOR14elseKEYWORD55=OPERATOR15enumKEYWORD56=OPERATO

3、R16extendsKEYWORD57%OPERATOR17finalKEYWORD58!OPERATOR18finallyKEYWORD59!=OPERATOR19floatKEYWORD60OPERATOR20forKEYWORD61=OPERATOR21gotoKEYWORD62OPERATOR22ifKEYWORD63OPERATOR23implementsKEYWORD64=OPERATOR24importKEYWORD65OPERATOR25instanceofKEYWORD66&OPERATOR26intKEYWORD67&OPERATOR27interfaceKEYWORD68

4、OPERATOR28longKEYWORD69|OPERATOR29nativeKEYWORD70|OPERATOR30newKEYWORD71OPERATOR31packageKEYWORD72;DEVIDER32protectedKEYWORD73,DEVIDER33publicKEYWORD74.DEVIDER34returnKEYWORD75(DEVIDER35strictfpKEYWORD76)DEVIDER36shortKEYWORD77DEVIDER37staticKEYWORD78DEVIDER38superKEYWORD79DEVIDER39switchKEYWORD80DE

5、VIDER40synchronizedKEYWORD81“DEVIDER41thisKEYWORD82DEVIDER2.单词结构描述（正规式或正规文法）|abstract|assert|boolean|break|byte|case|catch|char|class| const|continue|default|do|double|else|enum|extends|final|finally|float|for|goto|if|implements|import|instanceof|int|interface|long native|new|package|private|protect

6、ed|public|return|strictfp|short static|super|switch|synchronized|this|throw|throws|transient|try void|volatile|while +|+|-|-|*|/|=|=|%|！|!=|%|=|=|&|&|.|0|1|2|3|4|5|6|7|8|9A|B|.|X|Y|Z|a|b|.|x|y|z;|,|.|(|)|”|3. 单词状态转换图字母空白字母非字母非数字非关键字210SSS关键字非字母436非字母非数字5字母或数字数字非数字小数点数字非数字或.数字789A0分隔符BC操作符4. 算法描述 读取文

7、献到内存，逐个字母分析，并将连续的字母使用超前搜索组合成为变量或关键字；若是数字，则要判断是否为浮点数，即使用超前搜索的时候，判断扫描到的字符是否为小数点；若是分隔符或者操作符，则要到响应的表中查找并输出。三方案设计程序结构：1. 终结符封装的javabean：用于存储id，代表的实体entity，种类type；2. 关键字表存放在一个Map集合KeyWordTable中；分隔符表存放在一个Map集合DeviderTable中；操作符表存放在OperatorTable中；3. Scanner工具类用于扫描输入的java源程序；4. Analysis类用于分析词法，analysis方法分析词法。

8、程序流程图开始读取源文献扫描数字？添加分隔符NYYN是分隔符？扫描字母？读取源文献YYNY数字或.？扫描字母？添加操作符NN关键字？添加数字添加变量Y添加关键字四测试数据及运营结果1 正常测试数据（3组）及运营结果:扫描Analyst.javaWordType id=78, entity=, type=4, content=WordType id=78, entity=, type=4, content=WordType id=34, entity=return, type=1, content=returnWordType id=0, entity=, type=5, content=lis

9、tWordType id=72, entity=;, type=4, content=;WordType id=78, entity=, type=4, content=.扫描Test.javaWordType id=31, entity=package, type=1, content=packageWordType id=0, entity=, type=5, content=comWordType id=74, entity=., type=4, content=.WordType id=0, entity=, type=5, content=zcWordType id=74, enti

10、ty=., type=4, content=.WordType id=0, entity=, type=5, content=caWordType id=74, entity=., type=4, content=.WordType id=0, entity=, type=5, content=testWordType id=72, entity=;, type=4, content=;WordType id=33, entity=public, type=1, content=publicWordType id=8, entity=class, type=1, content=classWo

11、rdType id=0, entity=, type=5, content=TestWordType id=77, entity=, type=4, content=WordType id=0, entity=, type=5, content=privateWordType id=37, entity=static, type=1, content=staticWordType id=26, entity=int, type=1, content=intWordType id=0, entity=, type=5, content=aWordType id=55, entity=, type

12、=3, content=WordType id=0, entity=, type=2, content=0WordType id=72, entity=;, type=4, content=;WordType id=0, entity=, type=5, content=privateWordType id=17, entity=final, type=1, content=finalWordType id=13, entity=double, type=1, content=doubleWordType id=0, entity=, type=5, content=bWordType id=

13、55, entity=, type=3, content=WordType id=0, entity=, type=2, content=1.234WordType id=72, entity=;, type=4, content=;WordType id=33, entity=public, type=1, content=publicWordType id=37, entity=static, type=1, content=staticWordType id=46, entity=void, type=1, content=voidWordType id=0, entity=, type

14、=5, content=main五总结实验过程中碰到的问题及解决办法：扫描过程中出现非法字符的解决：t,n等：跳过六 附录：源代码（电子版）DeviderTable.javapackage com.zc.ca.db;import java.util.HashMap;import java.util.Map;import com.zc.ca.model.WordType;public class DeviderTable public static Map db = new HashMap();staticdb.put(;, new WordType(72,;,WordType.TYPE.DEV

15、IDER,;);db.put(, new WordType(73,WordType.TYPE.DEVIDER,);db.put(., new WordType(74,.,WordType.TYPE.DEVIDER,.);db.put(, new WordType(75,(,WordType.TYPE.DEVIDER,();db.put(), new WordType(76,),WordType.TYPE.DEVIDER,);db.put(, new WordType(77,WordType.TYPE.DEVIDER,);db.put(, new WordType(78,WordType.TYP

16、E.DEVIDER,);db.put(, new WordType(84,.,WordType.TYPE.DEVIDER,);db.put(, new WordType(85,.,WordType.TYPE.DEVIDER,);KeyWordTable.javapackage com.zc.ca.db;import java.util.HashMap;import java.util.Map;import com.zc.ca.model.WordType;public class KeyWordTable public static Map db= new HashMap();staticdb

17、.put(abstract, new WordType(1,abstract,WordType.TYPE.KEYWORD,abstract);db.put(assert, new WordType(2,assert,WordType.TYPE.KEYWORD,assert);db.put(boolean, new WordType(3,boolean,WordType.TYPE.KEYWORD,boolean);db.put(break, new WordType(4,break,WordType.TYPE.KEYWORD,break);db.put(case, new WordType(5,

18、case,WordType.TYPE.KEYWORD,case);db.put(catch, new WordType(6,catch,WordType.TYPE.KEYWORD,catch);db.put(char, new WordType(7,char,WordType.TYPE.KEYWORD,char);db.put(class, new WordType(8,class,WordType.TYPE.KEYWORD,class);db.put(const, new WordType(9,const,WordType.TYPE.KEYWORD,const);db.put(continu

19、e, new WordType(10,continue,WordType.TYPE.KEYWORD,continue);db.put(default, new WordType(11,default,WordType.TYPE.KEYWORD,default);db.put(do, new WordType(12,do,WordType.TYPE.KEYWORD,do);db.put(double, new WordType(13,double,WordType.TYPE.KEYWORD,double);db.put(else, new WordType(14,else,WordType.TY

20、PE.KEYWORD,else);db.put(enum, new WordType(15,enum,WordType.TYPE.KEYWORD,enum);db.put(extends, new WordType(16,extends,WordType.TYPE.KEYWORD,extends);db.put(final, new WordType(17,final,WordType.TYPE.KEYWORD,final);db.put(finally, new WordType(18,finally,WordType.TYPE.KEYWORD,finally);db.put(float,

21、new WordType(19,float,WordType.TYPE.KEYWORD,float);db.put(for, new WordType(20,for,WordType.TYPE.KEYWORD,for);db.put(goto, new WordType(21,goto,WordType.TYPE.KEYWORD,goto);db.put(if, new WordType(22,if,WordType.TYPE.KEYWORD,if);db.put(implements, new WordType(23,implements,WordType.TYPE.KEYWORD,impl

22、ements);db.put(import, new WordType(24,import,WordType.TYPE.KEYWORD,import);db.put(instanceof, new WordType(25,instanceof,WordType.TYPE.KEYWORD,instanceof);db.put(int, new WordType(26,int,WordType.TYPE.KEYWORD,int);db.put(interface, new WordType(27,interface,WordType.TYPE.KEYWORD,interface);db.put(l

23、ong, new WordType(28,long,WordType.TYPE.KEYWORD,long);db.put(native, new WordType(29,native,WordType.TYPE.KEYWORD,native);db.put(new, new WordType(30,new,WordType.TYPE.KEYWORD,new);db.put(package, new WordType(31,package,WordType.TYPE.KEYWORD,package);db.put(protected, new WordType(32,protected,Word

24、Type.TYPE.KEYWORD,protected);db.put(public, new WordType(33,public,WordType.TYPE.KEYWORD,public);db.put(return, new WordType(34,return,WordType.TYPE.KEYWORD,return);db.put(strictfp, new WordType(35,strictfp,WordType.TYPE.KEYWORD,strictfp);db.put(short, new WordType(36,short,WordType.TYPE.KEYWORD,sho

25、rt);db.put(static, new WordType(37,static,WordType.TYPE.KEYWORD,static);db.put(super, new WordType(38,super,WordType.TYPE.KEYWORD,super);db.put(switch, new WordType(39,switch,WordType.TYPE.KEYWORD,switch);db.put(synchronized, new WordType(40,synchronized,WordType.TYPE.KEYWORD,synchronized);db.put(th

26、is, new WordType(41,this,WordType.TYPE.KEYWORD,this);db.put(throw, new WordType(42,throw,WordType.TYPE.KEYWORD,throw);db.put(throws, new WordType(43,throws,WordType.TYPE.KEYWORD,throws);db.put(transient, new WordType(44,transient,WordType.TYPE.KEYWORD,transient);db.put(try, new WordType(45,try,WordT

27、ype.TYPE.KEYWORD,try);db.put(void, new WordType(46,void,WordType.TYPE.KEYWORD,void);db.put(volatile, new WordType(47,volatile,WordType.TYPE.KEYWORD,volatile);db.put(while, new WordType(48,while,WordType.TYPE.KEYWORD,while);OperatorTable.javapackage com.zc.ca.db;import java.util.HashMap;import java.u

28、til.Map;import com.zc.ca.model.WordType;public class OperatorTable public static Map db= new HashMap();staticdb.put(+, new WordType(49, +, WordType.TYPE.OPERATOR,+);db.put(+, new WordType(53, +, WordType.TYPE.OPERATOR,+);db.put(-, new WordType(50, -, WordType.TYPE.OPERATOR,-);db.put(-, new WordType(

29、54, -, WordType.TYPE.OPERATOR,-);db.put(*, new WordType(51, *, WordType.TYPE.OPERATOR,*);db.put(/, new WordType(52, /, WordType.TYPE.OPERATOR,/);db.put(=, new WordType(55, =, WordType.TYPE.OPERATOR,=);db.put(=, new WordType(57, =, WordType.TYPE.OPERATOR,=);db.put(%, new WordType(56, %, WordType.TYPE

30、.OPERATOR,%);db.put(!, new WordType(67, !, WordType.TYPE.OPERATOR,!);db.put(!=, new WordType(58, !=, WordType.TYPE.OPERATOR,!=);db.put(, new WordType(59, , WordType.TYPE.OPERATOR,);db.put(=, new WordType(61, =, WordType.TYPE.OPERATOR,=);db.put(, new WordType(70, , WordType.TYPE.OPERATOR,);db.put(, n

31、ew WordType(60, , WordType.TYPE.OPERATOR,);db.put(=, new WordType(62, =, WordType.TYPE.OPERATOR,=);db.put(, new WordType(71, , WordType.TYPE.OPERATOR,);db.put(&, new WordType(63, &, WordType.TYPE.OPERATOR,&);db.put(&, new WordType(68, &, WordType.TYPE.OPERATOR,&);db.put(, new WordType(64, , WordType

32、.TYPE.OPERATOR,);db.put(|, new WordType(65, |, WordType.TYPE.OPERATOR,|);db.put(|, new WordType(69, |, WordType.TYPE.OPERATOR,|);db.put(, new WordType(66, , WordType.TYPE.OPERATOR,);Analyst.javapackage com.zc.ca.exec;import java.io.File;import java.io.IOException;import java.util.ArrayList;import ja

33、va.util.Arrays;import java.util.List;import com.zc.ca.db.DeviderTable;import com.zc.ca.db.KeyWordTable;import com.zc.ca.db.OperatorTable;import com.zc.ca.model.WordType;public class Analyst private List list = new ArrayList();private String str;public Analyst(String string) this.str = string;public

34、List analysis() for (int i = 0; i :if (str.charAt(+i) = =)list.add(OperatorTable.db.get(=);else if (str.charAt(i) = )list.add(OperatorTable.db.get();else list.add(OperatorTable.db.get();i-;break;case :if (str.charAt(+i) = =)list.add(OperatorTable.db.get(=);else if (str.charAt(i) = )list.add(Operator

35、Table.db.get();else list.add(OperatorTable.db.get();i-;break;case &:if (str.charAt(+i) = &)list.add(OperatorTable.db.get(&);else list.add(OperatorTable.db.get(&);i-;break;case :list.add(OperatorTable.db.get();break;case |:if (str.charAt(+i) = |)list.add(OperatorTable.db.get(|);else list.add(Operator

36、Table.db.get(!);i-;break;case :list.add(OperatorTable.db.get();break;default:break;return list;public static void main(String args) File file = new File(src/com/zc/ca/test/Test.java);try Scanner scanner = new Scanner(file);Analyst analyst = new Analyst(scanner.getStringBuffer().toString();List list

37、= analyst.analysis();for (WordType wt : list) System.out.println(wt); catch (IOException e) e.printStackTrace();Scanner.javapackage com.zc.ca.exec;import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStreamReader;import java.

38、io.Reader;public class Scanner private StringBuffer sb = new StringBuffer();public Scanner(File file) throws IOException FileInputStream fis = new FileInputStream(file);init(fis);private void init(FileInputStream fis) throws IOException Reader reader = new InputStreamReader(fis); BufferedReader br = new BufferedReader(reader); String line = null; while (line = br.readLine()!=null) sb.append(line); public StringBuffer getStringBuffer()return sb;