课程实验报告--某种简单程序语言的词法分析器的设计与实现.docx
?编译原理?课程实验报告实验题目:某种简单程序语言的词法分析器的设计与实现专业:计算机科学与技术班级:11060341学号:11060341姓名:实验目的:设计一个词法分析程序,理解词法分析器实现的原理,掌握程序设计语言中的各类单词的词法分析方法,加深对词法分析原理的理解。实验任务:词法分析是从左向右扫描每行源程序的符号,拼成单词,换成统一的二元式(单词种别,单词符号的属性值)表示。对给定的程序通过词法分析器识别一个个单词符号,并以二元式(单词种别,单词符号的属性值)显示,本程序那么是通过对给定程序段分析后以单词符号和文字提示显示)实验流程:程序清单:#include<iostream>#include<cstd沁>#include<cstring>usingnamespacestd;intk=0;structword(charname10;intkind;word1000;charkey35l0=,scan,"short,int","1ong",',float","double",char","struct,"union'"printf',typedef',',const'"unsigned','signed",extern","register","static","volatile,'void",i,else'',"switch'case",'for'"do",while,"goto","continue","break",default",sizeof,"retum",include",bool";boolcmp(chara)(inti;for(intk=0;k<35;k+)(if(strcmp(a,keyk)=O)return1;1return0;)intmain()(#ifdefLOCALfreopen("in.txt",m,stdin);freopen("out.txt,w'stdout);#endifintp,q,flag;charal000,bl0,ch;while(gets(a)(p=o;intlen=strlen(a);while(p<len)(ch=a;memset(b,0,sizeof(b);while(ch='")(p+;ch=ap;)if(ch>='a'<fcAch<=)(ch>=,A'ch<=,Z,)ch=,J)(flag=O;q=0;While(Ch>='a'&&ch<=Z)IKch>='A&&chv=Z)IlCh=UI(Ch>='0'&&ch<=9)(if(ch>=,0'<fe<fcch<=,9')ch=(J)flag=l;blq+=ch;P+÷ch=ap;1if(flag=l)(strcpy(wordk.name,b);wordk+.kind=l;)elseif(flag=O)(if(ch='V,ch=")(strcpy(wordk.name,b);wordk+÷.kind=2;1elseif(cmp(b)=l)strcpy(wordk.name,b);wordk+J.kind=3;elsestrcpy(wordk.name,b);wordk+J.kind=l;elseif(ch>=0'<fech<='9,)ch=,-)(intt=p-1;if(at>='0,<feAat<=,91at>='a'(fe<feat<='z,at>=,A'<fcat<=,Z')(P+;ch=ap;if(ch='-'ch='-)b0=*-;bl=ch;strcpy(wordk.name,b);wordk+J.kind=5;ch=a+p;elseb0=*-;strcpy(wordk.name,b);wordk+J.kind=5;elseq=0;bq+=ch;p+;ch=ap;While(Ch>='0'&&ch<='9')|ch='.')(bq+=ch;P+;ch=ap;strcpy(wordk.name,b);wordk+.kind=2;else')ch='(,if(ch='('ch=),ch=''ch='ch=,ch=,),ch=*,'ch=ch=,fch='',ch='ch=)'ch=,ch=,ch=,ch="),(bl=ch;strcpy(wordk.name,b);wordk+.kind=4;ch=a+p;)elseif(ch='%l|ch=w)(b0=ch;strcpy(wordk.name,b);wordk+.kind=5;ch=a+p;)elseif(ch=-÷,)(P÷+;ch=alp;if(ch='+'ch='=')(bLO='+;blJ=ch;strcpy(wordk.name,b);wordk+.kind=5;ch=a+p;)else(bLO='+;strcpy(wordk.name,b);wordk+.kind=5;1)elseif(ch=-*')(P+;ch=ap;if(ch=*'ch=)blOJ=*t;bll=ch;strcpy(wordk.name,b);wordk+.kind=5;ch=a+pj;)else(b0,*'strcpy(wordk.name,b);wordk+÷J.kind=5;1)elseif(ch=7,)(P÷+;ch=ap;if(ch=,ch=,=)(bLO=7,;bl=ch;strcpy(wordk.name,b);wordk+÷J.kind=5;ch=a+p;1else(bLO=7,;strcpy(wordk.name,b);wordk+J.kind=5;1)elseif(ch='-)(P+;ch=ap;if(ch='=)(b0=bl=1=;strcpy(wordk.name,b);wordk+.kind=5;ch=a+p;b0=,=;strcpy(wordk.name,b);wordk+÷.kind=5;elseif(ch='>,)(P+;ch=ap;if(ch=>ch='=')(b0=>,;hll=ch;strcpy(wordk.name,b);wordk+.kind=5;ch=a+pj;)else(bl=,>,;strcpy(wordk.name,b);wordk+÷J.kind=5;1)elseif(ch=-<|)(P÷+;ch=ap;if(ch='<'ch='=')(bLO=,<,;bl=ch;strcpy(wordk.name,b);wordk+÷J.kind=5;ch=a+p;1else(bLO=,<,;strcpy(wordk.name,b);wordk+.kind=5;P+;ch=ap;if(ch='=)(b0='!;bll='='strcpy(wordk.name,b);wordk+.kind=5;ch=a+p;1else(b0=T;strcpy(wordk.name,b);wordk+.kind=5;)elseif(ch=-<fe,)(P+;ch=ap;if(ch,)(bij=bI='&'strcpy(wordk.name,b);wordk+.kind=5;ch=a+pj;)else(bl='<fe'strcpy(wordk.name,b);wordk+÷J.kind=5;1)elseif(ch=-')(P÷+;ch=ap;if(ch=T)(bO=bl=T;strcpy(wordk.name,b);wordk+J.kind=5;ch=a+p;elseb0=T;strcpy(wordk.name,b);wordk+J.kind=5;for(inti=0;i<k;i+)(switch(wordi.kind)(case 1:Printf("(标识符J);break;case 2:PrintfC(常量break;case 3:Primf("(关键字break;case 4:Printr(界符break;case 5:Prin日”(运算符break;printf("%s)n',wordi.name);intal=0,a2=0,a3=0,a4=0,a5=0;for(inti=O;i<k;i+)(if(wordi.kind=l)al+;elseif(wordli.kind=2)a2+;elseif(wordi.kind=3)a3+;elseif(wordli.kind=4)a4+;elseif(wordi.kind=5)a5+;)Printf("标识符:%dn常量:%dn关键字:%dn界符:%dn运算符:%dn,',al,a2,a3,a4,a5);return0;)运行结果: