词法分析程序源代码

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
char TOken[10];//分开进行比较
char ch;
char r1[]={"auto"};
char r2[]={"break"};
char r3[]={"case"};
char r4[]={"char"};
char r5[]={"const"};
char r6[]={"continue"};
char r7[]={"default"};
char r8[]={"do"};
char r9[]={"double"};
char r10[]={"else"};
char r11[]={"enum"};
char r12[]={"extern"};
char r13[]={"float"};
char r14[]={"for"};
char r15[]={"goto"};
char r16[]={"if"};
char r17[]={"int"};
char r18[]={"long"};
char r19[]={"register"};
char r20[]={"return"};
char r21[]={"short"};
char r22[]={"signed"};
char r23[]={"sizeof"};
char r24[]={"static"};
char r25[]={"struct"};
char r26[]={"switch"};
char r27[]={"typedef"};
char r28[]={"union"};
char r29[]={"unsigned"};
char r30[]={"void"};
char r31[]={"volatile"};
char r32[]={"while"};
char r33[]={"end"};
char r34[]={"include"};
char r35[]={"stdio"};
char r36[]={"string"};
char r37[]={"main"};
char r38[]={"stdlib"};//这是我定义的
char A[10000];//输入的所有值
int syn,row;
int n,m,p,sum,j;
static int i = 0;
void scaner();
int main()
{
    row = 0 ;
    p = 0 ;
    printf("Please input string:(end of ‘@‘)\n");
    do
    {
        scanf("%c",&ch);
        A[p]=ch;
        p++;
    }//输入值到数组A【】中，以@结束
    while(ch!=‘@‘);
    do
    {
        scaner();//进入函数进行判定
        switch(syn)
        {
        case 40: printf("(%d,%d)\n",syn,sum); break;//如果是40，那么就是数字
        case 0: printf("(%d,%c)\n",syn,TOken[0]);break;//如果是0，那么是@ 结束
        case -2: row=row++;break;
        default: printf("(%d,%s)\n",syn,TOken);break;//否则，就是变量名、关键词
        }
    }
    while (syn!=0);
}
void scaner()
{
    /*共分为三大块，分别是标示符、数字、符号，对应下面的 if else if 和 else */
    for(n=0;n<7;n++)
        TOken[n]=0;//每次循环完就清零
    ch=A[i];
    while(ch==‘ ‘||ch==‘\n‘)//如果字符是空格或者回车，跳过
    {
        i++;
        ch=A[i];
    }
    if((ch>=‘a‘&&ch<=‘z‘)||(ch>=‘A‘&&ch<=‘Z‘)) //可能是标示符或者变量名
    {
        m=0;
        while((ch>=‘0‘&&ch<=‘9‘)||(ch>=‘a‘&&ch<=‘z‘)||(ch>=‘A‘&&ch<=‘Z‘))//找到一个变量名或者关键字，直到遇到空格为止
        {
            TOken[m]=ch;m++;
            i++;ch=A[i];
        }
        TOken[m]=‘\0‘;//将识别出来的字符和已定义的标示符作比较， //因为定义的begin为1，if为2......
        if(strcmp(TOken,r1)==0){syn=1;}
        else if(strcmp(TOken,r2)==0){syn=2; }
        else if(strcmp(TOken,r3)==0){syn=3;}
        else if(strcmp(TOken,r4)==0){syn=4;}
        else if(strcmp(TOken,r5)==0){syn=5;}
        else if(strcmp(TOken,r6)==0){syn=6;}
        else if(strcmp(TOken,r7)==0){syn=7;}
        else if(strcmp(r8,TOken)==0){syn=8;}
        else if(strcmp(r9,TOken)==0){syn=9;}
        else if(strcmp(r10,TOken)==0){syn=10;}
        else if(strcmp(r11,TOken)==0){syn=11;}
        else if(strcmp(r12,TOken)==0){syn=12;}
        else if(strcmp(r13,TOken)==0){syn=13;}
        else if(strcmp(r14,TOken)==0){syn=14;}
        else if(strcmp(r15,TOken)==0){syn=15;}
        else if(strcmp(r16,TOken)==0){syn=16;}
        else if(strcmp(r17,TOken)==0){syn=17;}
        else if(strcmp(r18,TOken)==0){syn=18;}
        else if(strcmp(r19,TOken)==0){syn=19;}
        else if(strcmp(r20,TOken)==0){syn=20;}
        else if(strcmp(r21,TOken)==0){syn=21;}
        else if(strcmp(r22,TOken)==0){syn=22;}
        else if(strcmp(r23,TOken)==0){syn=23;}
        else if(strcmp(r24,TOken)==0){syn=24;}
        else if(strcmp(r25,TOken)==0){syn=25;}
        else if(strcmp(r26,TOken)==0){syn=26;}
        else if(strcmp(r27,TOken)==0){syn=27;}
        else if(strcmp(r28,TOken)==0){syn=28;}
        else if(strcmp(r29,TOken)==0){syn=29;}
        else if(strcmp(r30,TOken)==0){syn=30;}
        else if(strcmp(r31,TOken)==0){syn=31;}
        else if(strcmp(r32,TOken)==0){syn=32;}
        else if(strcmp(r33,TOken)==0){syn=33;}
        else if(strcmp(r34,TOken)==0){syn=34;}
        else if(strcmp(r35,TOken)==0){syn=35;}
        else if(strcmp(r36,TOken)==0){syn=36;}
        else if(strcmp(r37,TOken)==0){syn=37;}
        else if(strcmp(r38,TOken)==0){syn=38;}
        else{syn=100;}    //变量名
    }
    else if((ch>=‘0‘&&ch<=‘9‘)) //数字
    {
        sum=0;
        while((ch>=‘0‘&&ch<=‘9‘))
        {
            sum=sum*10+ch-‘0‘;//显示其数字sum
            i++;
            ch=A[i];
        }
        syn=40;
    }
    else switch(ch) //其他字符
    {
case‘<‘:m=0;TOken[m]=ch;m++;
    i++;ch=A[i];
    if(ch==‘=‘)//<>为22
    {
        syn=41;
        TOken[m]=ch;m++;i++;
    }
    else
    {
        syn=46;
    }
    break;
case‘>‘:m=0;TOken[m]=ch;m++;
    i++;ch=A[i];
    if(ch==‘=‘)
    {
        syn=42;
        TOken[m]=ch;m++;i++;
    }
    else
    {
        syn=47;
    }
    break;
case‘:‘:m=0;TOken[m]=ch;m++;
    i++;ch=A[i];
    if(ch==‘=‘)
    {
        syn=44;
        TOken[m]=ch;m++;i++;
    }
    else
    {
        syn=49;
    }
    break;
case‘@‘:syn=0;
    TOken[0]=ch;
    i++;
    break;
case‘=‘:syn=48;
    TOken[0]=ch;
    i++;
    break;
case‘#‘:syn=50;
    TOken[0]=ch;
    i++;
    break;
case‘+‘:syn=50;
    TOken[0]=ch;
    i++;
    break;
case‘-‘:syn=51;
    TOken[0]=ch;
    i++;
    break;
case‘*‘:syn=52;
    TOken[0]=ch;
    i++;
    break;
case‘/‘:syn=53;
    TOken[0]=ch;
    i++;
    break;
case‘(‘:syn=54;
    TOken[0]=ch;
    i++;
    break;
case‘)‘:syn=55;
    TOken[0]=ch;
    i++;
    break;
case‘{‘:syn=56;
    TOken[0]=ch;
    i++;
    break;
case‘}‘:syn=57;
    TOken[0]=ch;
    i++;
    break;
case‘;‘:syn=58;
    TOken[0]=ch;
    i++;
    break;
case‘.‘:syn=59;
    TOken[0]=ch;
    i++;
    break;
case‘\‘‘:syn=60;
    TOken[0]=ch;
    i++;
    break;
case‘\n‘:
    syn=-2;
    break;
default: syn=-1;
    break;
    }
}