编译原理第三版附带的实验源码

Scanner:#include <stdio.h>#include <stdlib.h>#include <string.h>#define _KEY_WORD_END "waiting for your expanding"typedef struct{int typenum;char * word;} WORD;char input[255];char token[255]="";int p_input;int p_token;char ch;char* KEY_WORDS[]={"main","int","char","if","else","for","while",_KEY_WORD_END}; WORD* scaner();void main(){int over=1;WORD* oneword=new WORD;printf("Enter Your words(end with $):");scanf("%[^$]s",input);p_input=0;printf("Your words:\n%s\n",input);while(over<1000&&over!=-1){oneword=scaner();if(oneword->typenum<1000)printf("(%d,%s)",oneword->typenum,oneword->word);over=oneword->typenum;}printf("\npress # to exit:");scanf("%[^#]s",input);}char m_getch(){ch=input[p_input];p_input=p_input+1;return (ch);}void getbc(){while(ch==' '||ch==10){ch=input[p_input];p_input=p_input+1;}}void concat(){token[p_token]=ch;p_token=p_token+1;token[p_token]='\0';}int letter(){if(ch>='a'&&ch<='z'||ch>='A'&&ch<='Z')return 1;else return 0;}int digit(){if(ch>='0'&&ch<='9')return 1;else return 0;}int reserve(){int i=0;while(strcmp(KEY_WORDS[i],_KEY_WORD_END)){ if(!strcmp(KEY_WORDS[i],token)){return i+1;}i=i+1;}return 10;}void retract(){p_input=p_input-1;}char* dtb(){return NULL;}WORD* scaner(){WORD* myword=new WORD;myword->typenum=10;myword->word="";p_token=0;m_getch();getbc();if(letter()){while(letter()||digit()){concat();m_getch();}retract();myword->typenum=reserve();myword->word=token;return(myword);}else if(digit()){while(digit()){concat();m_getch();}retract();myword->typenum=20;myword->word=token;return(myword);}else switch(ch){case '=': m_getch();if (ch=='='){myword->typenum=39;myword->word="==";return(myword);}retract();myword->typenum=21;myword->word="=";return(myword);break;case '+': myword->typenum=22;myword->word="+";return(myword);break;case '-': myword->typenum=23;myword->word="-";return(myword);break;case '*': myword->typenum=24;myword->word="*";return(myword);break;case '/': myword->typenum=25;myword->word="/";return(myword);break;case '(': myword->typenum=26;myword->word="(";return(myword);break;case ')': myword->typenum=27;myword->word=")";return(myword);break;case '[': myword->typenum=28;myword->word="[";return(myword);break;case ']': myword->typenum=29;myword->word="]";return(myword);break;case '{': myword->typenum=30;myword->word="{";return(myword);break;case '}': myword->typenum=31;myword->word="}";return(myword);break;case ',': myword->typenum=32;myword->word=",";return(myword);break;case ':': myword->typenum=33;myword->word=":";return(myword);break;case ';': myword->typenum=34;myword->word=";";return(myword);break;case '>': m_getch();if (ch=='='){myword->typenum=37;myword->word=">=";return(myword);}retract();myword->typenum=35;myword->word=">";return(myword);break;case '<': m_getch();if (ch=='='){myword->typenum=38;myword->word="<=";return(myword);}retract();myword->typenum=36;myword->word="<";return(myword);break;case '!': m_getch();if (ch=='='){myword->typenum=40;myword->word="!=";return(myword);}retract();myword->typenum=-1;myword->word="ERROR";return(myword);break;case '\0': myword->typenum=1000;myword->word="OVER";return(myword);break;default: myword->typenum=-1;myword->word="ERROR";return(myword);}}Parsing:#include<stdio.h>#include<string.h>#include<stdlib.h>int syn,p_input,p_token,kk;char ch;char input[100];char token[100]="";char* key_words[]={"begin","if","then","while","do","end"}; int expression();void m_getch();int letter();int digit();int compare();void c_token();void scaner();void main(){FILE *fin;char buffer[100];int size;if((fin=fopen("test.txt","r"))==NULL){printf("Cannot open the file!\n");exit(-1);}fin=fopen("test.txt","r");while(fgets(buffer,100,fin)!=NULL){strcat(input,buffer);}lrparser();printf("\npress # to exit:\n");scanf("%[^#]",input);fclose(fin);}{ scaner();if(syn==1){scaner();yucu();if(syn==6){scaner();if((syn==0)&&(kk==0)){printf("Success\n");return 1;}}else{if(kk!=1)printf("no end error\n");kk=1;return 0;}}else{printf("no begin error\n");kk=1;return 0;}}int yucu(){statement();while (syn==29){scaner();statement();}return 1;}{p_token=0;m_getch();while(ch==' '||ch==10)m_getch();if(letter()){while(letter()||digit()){c_token();m_getch();}p_input--;syn=compare();}else if(digit()){while(digit()){c_token();m_getch();}p_input--;syn=11;}else switch(ch){case '=': c_token();m_getch();if(ch=='='){syn=24;c_token();}else{p_input--;syn=21;}break;case '<': c_token();m_getch();if(ch=='=')syn=25;c_token();}else if(ch=='>'){syn=26;c_token();}else{ p_input--;syn=22;}break;case '>': c_token();m_getch();if(ch=='='){syn=27;c_token();}else{p_input--;syn=23;}break;case '+': syn=13;c_token();break;case '-': syn=14;c_token();break;case '*': syn=15;c_token();break;case '/': syn=16;c_token();break;case '(': syn=17;c_token();break;case ')': syn=18;c_token();break;case '{': syn=19;c_token();break;case '}': syn=20;c_token();break;case ';': syn=29;c_token();break;case '#': syn=0;break;default : syn=-1;c_token();}}void m_getch(){ch=input[p_input];p_input++;}void c_token(){token[p_token]=ch;p_token++;token[p_token]='\0';}int compare(){int n;for(n=0;n<6;n++){if(strcmp(key_words[n],token)==0)return n+1;}return 10;}int letter(){if(ch>='a'&&ch<='z'||ch>='A'&&ch<='Z')return 1;else return 0;}int digit(){if(ch>='0'&&ch<='9')return 1;else return 0;}int expression(){term();while (syn==13||syn==14){scaner();term();}return 1;}int factor(){if(syn==10||syn==11)scaner();else if(syn==17){scaner();expression();if (syn==18){scaner();}else { printf("输入错误\n");kk=1;return 0;} }else {printf("输入表达式错误\n");kk=1;return 0;} return 1;}int term(){factor();while(syn==15||syn==16){scaner();factor();}return 1;}int statement(){if(syn==10){scaner();if (syn==21){scaner();expression();}else {printf("输入赋值错误\n");kk=1;} }else {printf("输入语句错误\n");kk=1;}return 1;}。