v1.0可编辑可修改1#include<>#include<>#include<>#defineMAX_COUNT1024#defineILLEGAL_CHAR_ERR1#defineUNKNOWN_OPERATOR_ERR2/*从标准输入读入第一个非空白字符(换行符除外)*/chargetnbc(){charch;ch=getchar();while(1){if(ch=='\r'||ch=='\t'||ch==''){ch=getchar();}else{break;}}returnch;v1.0可编辑可修改2}/*判断character是否为字母*/boolletter(charcharacter){if((character>='a'&&character<='z')||(character>='A'&&character<='Z'))returntrue;elsereturnfalse;}/*判断character是否为数字*/booldigit(charcharacter){if(character>='0'&&character<='9')returntrue;elsereturnfalse;}/*回退字符*/voidretract(char&character){ungetc(character,stdin);character=NULL;}/*返回保留字的对应种别*/intreserve(char*token)v1.0可编辑可修改3{if(strcmp(token,"begin")==0)return1;elseif(strcmp(token,"end")==0)return2;elseif(strcmp(token,"integer")==0)return3;elseif(strcmp(token,"if")==0)return4;elseif(strcmp(token,"then")==0)return5;elseif(strcmp(token,"else")==0)return6;elseif(strcmp(token,"function")==0)return7;elseif(strcmp(token,"read")==0)return8;elseif(strcmp(token,"write")==0)return9;elsereturn0;}/*返回标识符的对应种别*/intsymbol(){v1.0可编辑可修改4return10;}/*返回常数的对应种别*/intconstant(){return11;}/*按照格式输出单词符号和种别*/voidoutput(constchar*token,intkindNum){printf("%16s%2d\n",token,kindNum);}/*根据行号和错误码输出错误*/boolerror(intlineNum,interrNum){char*errInfo;switch(errNum){caseILLEGAL_CHAR_ERR:errInfo="出现字母表以外的非法字符";break;caseUNKNOWN_OPERATOR_ERR:errInfo="出现未知运算符";break;default:v1.0可编辑可修改5errInfo="未知错误";}if(fprintf(stderr,"***LINE:%d%s\n",lineNum,errInfo)>=0)returntrue;elsereturnfalse;}/*词法分析函数，每调用一次识别一个符号*/boolLexAnalyze(){staticintlineNum=1;charcharacter;chartoken[17]="";character=getnbc();switch(character){case'\n':output("EOLN",24);lineNum++;break;caseEOF:output("EOF",25);returnfalse;;if(fullName!=NULL)v1.0可编辑可修改6strncpy(out,fullName+1,strlen(fullName)-1-strlen(extension));elsestrncpy(out,in,strlen(in)-strlen(extension));}/*初始化函数，接收输入文件地址，并打开输入、输出、错误文件、将标准输入重定向到输入文件，将标准输出重定向到输出文件，标准错误重定向到错误文件*/boolinit(intargc,char*argv[]){if(argc!=2){returnfalse;}else{char*inFilename=argv[1];yd");rr");if(freopen(inFilename,"r",stdin)!=NULL&&freopen(outFilename,"w",stdout)!=NULL&&freopen(errFilename,"w",stderr)!=NULL)returntrue;elsereturnfalse;}}voidmain(intargc,char*argv[])//argv[1]是输入文件地址v1.0可编辑可修改7{if(init(argc,argv)){while(LexAnalyze()){}}fclose(stdin);fclose(stdout);fclose(stderr);return;}
