C语言词法分析器.doc

b2a3fdebdafb4953e416061301ac9dcc.pdf 2008-06-12周宏C语言词法分析器一，实验目的 1加强对词法分析原理、方法和基本实现技术的理解；2.灵活运用这学期所学的知识对词法分析，语法分析有进一步的理解；3强化对系统软件综合工程实现能力的训练；二实验内容 用C语言(或 C+ )作为宿主语言完成： C语言(win-TC , ANSI C或turbo C 2.0)词法分析器的设计和实现。 三实验要求1. 编写C语言词法分析器的源程序并调试通过； 2. 通过测试程序的验收； 3. 提交简明扼要的书面实验报告，内容包括：属性字设计；源程序主要流程；主要数据结构设计，程序。四，程序流程图（1） main主程序图处理每个字符 开始结束是否结束判断并输出每个单词类型属性。Scan（）函数，分析并返回每个单词的属性Run=1？初始化数组Program,words提示输入程序字符串输入并读取程序字符初始化 是（2） Scan（）函数流程图初始化数组，标志符判断并标志是否为关键字判断并标志为运算符或标点符号判断并标志为其它类型Return返回sign数值1五，原程序代码#include#includeint i,j,k,sign,number,flag,run,sum,autuor;/*flag which is use to judge the string is keywords or not!*/char ch;char words10 = ;char program500;int Scan(char program) char * keywords39 = auto,default,do, extern,goto, int,short,static,struct,switch, typedef,void,break,case,char, const,continue,double,else, enum, float,for,if,long, register, return,signed,zhouhong,sizeof,union, unsigned,volatile,while,main,printf, scanf,include,define,string ; number = 0; flag = 0; j = 0; ch = programi+; /* To handle the lettle space ands tab*/ while (ch = ) | (ch = t) | (ch = r)|(ch=n) ch=programi+; /* 跳过不理睬 */ /*handle letters*/ if (ch = a) & (ch = a) & (ch = z ) wordsj+=ch; ch=programi+; i-; wordsj+ = 0; for (k = 0; k = 0) & (ch = 0 ) & (ch : if (ch = ) wordsj+ = ch; wordsj = 0; ch = programi+; if (ch = =) wordsj+ = ch; wordsj = 0; sign = 403; /* = */ else if(ch=) wordsj+ =ch; wordsj =0; sign =419; /* */ else i-;sign = 404; /* */ break; case: if (ch = ) wordsj+ = ch; wordsj = 0; ch = programi+; if (ch = =) wordsj+ = ch; wordsj = 0; sign = 405; else if(ch= 0) & (ch = 0) & (ch = 9) ) wordsj+ = ch; ch = programi+; wordsj = 0; sign = 1000; /* 标志为1000 */ /* 负数 */ i-; break; else i-;sign = 414; break; case*: if (ch = *) wordsj+ = ch; wordsj = 0; ch = programi+; if (ch = =) wordsj+ = ch; wordsj = 0; sign = 415; else i-; sign = 416; break;case/: if (ch = /) wordsj+ = ch; wordsj = 0; ch = programi+; if (ch = =) wordsj+ = ch; wordsj = 0; sign = 417; else i-; sign = 418; break;case:if(ch=) wordsj+ = ch; wordsj = 0; sign =421; break; case;: wordsj = ch; wordsj+1 = 0; sign = 501; break;case(: wordsj = ch; wordsj+1 = 0; sign = 502; break;case): wordsj = ch; wordsj+1 = 0; sign = 503; break;case: wordsj = ch; wordsj+1 = 0; sign = 504; break;case: wordsj = ch; wordsj+1 = 0; sign = 505; break;case: wordsj = ch; wordsj+1 = 0; sign = 506; break;case: wordsj = ch; wordsj+1 = 0; sign = 507; break;case: wordsj = ch; wordsj+1 = 0; sign = 508; break;case: wordsj = ch; wordsj+1 = 0; sign = 509; break;case%: if (ch = %) wordsj+ = ch; wordsj = 0; ch = programi+; if (ch = =) wordsj+ = ch; wordsj = 0; sign = 510; else i-; sign = 511; break;case,:wordsj = ch;wordsj+1 = 0;sign = 512;break;case#:wordsj = ch;wordsj+1 = 0;sign = 513;break;case:wordsj = #;wordsj+1 = 0;sign = 0;break;default: sign = -1; /* 错误 */break; return sign;void display()printf(Autuor: zhouhongn); printf(calss: computer 0502n); printf(time: 2008-06-10n); printf(Email: n); printf(QQ: 454350734n);int main() i=0; run=1; while(run) int ent; int j; ent=autuor=sum=0; for( j = 0; j 500; j+) programj = ; for( j = 0; j =1&sign=401&sign=501&sign=513) printf(symbol , %8s, %5d) ,words,sign); sum+; ent=1; if(sum%2=0&ent=1) puts(r),ent=0; while (sign != 0); puts(n); if(autuor=1)display(), puts(n); printf(continue?(Y or N):); getchar(); ch=getchar(); if(ch=N|ch=n) run=0; return 0; getchar();六，程序运行截图（1） 当程序开始时会出现程序输入界面，如下面图（一）所示： 图（一）（2） 接着输入C语言原程序，如下面图（二）所示： 图（二）（3）按回车键后，程序就会运行并输出结果，如下面图（三）所示： 图（三）（4）此程序另外还加入了一个身体标志，当程序输入的单词中包含“zhouhong” 的字符串是，运行程序后，会在正常输出的最后面出现几行关于个人身份信息。如下面图（四）所示： 图（四）七，个人体会和经验总结（1）刚开始，这个程序是先看了网上的一个类似程序之后，在他的基础上面