main.c

词法分析器（编译原理） Java语言词法分析器的设计与实现

                     ch = readchar();
                     line1++;
                     if(ch == '=') {
                         sp = "0x110";
                         flow.site = 29;
                     }
                     else {
                         sp = "0x119";
                         flow.site = 28;
                     } 
             }
             else {
                 sp = "0x119";
                 flow.site = 26 + i;
                 untread();
             }
     }
     else {
     sp = "0x118";
     flow.site = 24 + i;
     untread();
     }
     strcpy(flow.attribute,sp);
     total++;
     linetotal++;
     writefile(); 
}

void op4(char a) {
     char *sp; 
     line1++;
     line2 = line1; 
     total++;
     linetotal++; 
     
     switch (a) {
            case '?':
                 sp = "0x111";
                 flow.site = 34;
                 break; 
            case ':':
                 sp = "0x111";
                 flow.site = 35;
                 break; 
            case '~':
                 sp = "0x11c";
                 flow.site = 36;
                 break; 
            case '[':
                 sp = "0x11d";
                 flow.site = 37;
                 break; 
            case ']':
                 sp = "0x11d";
                 flow.site = 38;
                 break; 
            case '(':
                 sp = "0x11d";
                 flow.site = 39;
                 break; 
            case ')':
                 sp = "0x11d";
                 flow.site = 40;
                 break; 
            case ',':
                 sp = "0x120";
                 flow.site = 42;
                 break; 
            case '{':
                 sp = "0x121";
                 flow.site = 43;
                 break; 
            case '}':
                 sp = "0x121";
                 flow.site = 44;
                 break; 
            case ';':
                 sp = "0x122";
                 flow.site = 45;
                 break; 
     }
     strcpy(flow.attribute,sp);
     writefile();
}
//扫描主函数 
void scan() {
     char ch,*sp;
     int i; 
     ch = readchar();

     character = ch;           //
     switch (ch) {
            case 'a': 
            case 'b':
            case 'c':
            case 'd':
            case 'e':
            case 'f':
            case 'g':
            case 'h':
            case 'i':
            case 'j':
            case 'k':
            case 'l':
            case 'm':
            case 'n':
            case 'o':
            case 'p':
            case 'q':
            case 'r':
            case 's':
            case 't':
            case 'u':
            case 'v':
            case 'w':
            case 'x':
            case 'y':
            case 'z':
                 
            case 'A':
            case 'B':
            case 'C':
            case 'D':
            case 'E':
            case 'F':
            case 'G':
            case 'H':
            case 'I':
            case 'J':
            case 'K':
            case 'L':
            case 'M':
            case 'N':
            case 'O':
            case 'P':
            case 'Q':
            case 'R':
            case 'S':
            case 'T':
            case 'U':
            case 'V':
            case 'W':
            case 'X':
            case 'Y':
            case 'Z':
                 key();
                 break;    
                 
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9':
            case '.': 
                 number();
                 break;
                 
            case '$':
            case '_': 
                 identifier();
                 break; 
                 
            case '\n': 
                 row++; 
                 line1 = 0;
                 linetotal = 0;
                 break;
            case ' ':
                 sp = "0x102";
                 strcpy(flow.attribute,sp);
                 flow.site = 46;            //
                 line1++;
                 line2 = line1; 
                 writefile(); 
                 break;
                 
            case '\'':
                 line1++;
                 line2 = line1;  
                 sp = "0x106";
                 strcpy(flow.attribute,sp);
                 flow.site = 0;   
                 total++;  
                 linetotal++; 
                 writefile();                             
                 ch = readchar(); 
                 instring[0] = ch; 
                 line1++; 
                 line2 = line1; 
                 if( (ch = readchar()) == '\'') { 
                     line1++;
                     instring[1] = '\0'; 
                     total++;  
                     linetotal++; 
                     writefile();
                 }
                 else {          //只有一个单引号为错误单词 
                       instring[1] = instring[0];
                       instring[0] = '\''; 
                       instring[2] = '\0';
                       line1++;
                       error(instring);
                 } 
                 line2 = line1; 
                 total++;  
                 linetotal++; 
                 instring[0] = '\'';
                 instring[1] = '\0'; 
                 writefile(); 
                 break; 
                 
            case '"':
                 line1++;
                 line2 = line1;
                 sp = "0x109";
                 strcpy(flow.attribute,sp);
                 i = 0;  
                 total++; 
                 linetotal++;
                 flow.site = 0;
                 writefile(); 
                 line2++;
                 while( (ch = readchar()) != '"') {
                        line1++; 
                        instring[i] = ch;
                        i++; 
                        if(ch == ' ' || ch == '\n') {     //以空格和回车符作为单词结束的标志 
                             linetotal++;
                             total++; 
                             instring[i-1] = '\0'; 
                             strcpy(strings[count7],instring);
                             flow.site = count7;
                             writefile(); 
                             i = 0;
                             count7++;
                             line2 = line1;
                             line2++; 
                             if(ch == '\n') { 
                                   linetotal = 0;
                                   line1 = 0;
                                   row++;
                             } 
                        } 
                        if(i == 50) {    //字符串最多有50个单词 
                             printf("the string is too long,please write more blank space."); 
                             exit(0) ;
                        } 
                 }
                 line1++;
                 linetotal++;
                 total++; 
                 instring[i] = '\0'; 
                 strcpy(strings[count7],instring);
                 flow.site = count7;
                 writefile(); 
                 count7++;
                 line2 = line1;
                 flow.site = 0;
                 writefile(); 
                 break; 
                 
            case '=':
                 line1++;
                 line2 = line1;
                 ch = readchar();
                 if(ch == '=') { 
                       flow.site = 0; 
                       sp = "0x117";
                 } 
                 else { 
                      sp = "0x110";
                      flow.site = 1; 
                      untread(); 
                 } 
                 strcpy(flow.attribute,sp);
                 total++;
                 linetotal++;
                 writefile();    
                 break;    
                 
            case '+':    
            case '-':    
                 op1(ch); 
                 break;      
                 
            case '*':       
            case '/':
            case '%':
            case '&':
            case '^':
            case '|':   
                 op2(ch); 
                 break; 
                 
            case '>':
            case '<':
                 op3(ch); 
                 break;  
            
            case '?':
            case ':':
            case '~':
            case '[':
            case ']':
            case '(':
            case ')':
            case ',':
            case '{':
            case '}':
            case ';':
                 op4(ch); 
                 break; 
                 
            case '\t':
                 line1 += 4;
                 break;
     }
}
//主函数 
int main() {
    int i = 0;
    char ch1,sp;
    char filename[20] ={"scanner_output.txt"};  
    initi(); 
    readin1();
    readin2(); 
    readin1();
    character = 'a';
    while(character != EOF) { 
        scan(); 
    }
    fp = fopen(filename,"r");
    ch1 = fgetc(fp);
    while(ch1 != EOF) {
        putchar(ch1);
        ch1 = fgetc(fp);
    }
    fclose(fp); 
    return 0;
}