pl0词法分析器(C语言版)

pl0词法分析器(C语言版)#include #include #include void init(); void getsym(); enum symbol { nul,ident,number,plus,minus,times,slash,oddsym,eql,neq, lss,leq,gtr,geq,lparen,rparen,comma,semicolon,period,becomes, beginsym,endsym,ifsym,thensym,whilesym,writesym,readsym,dosym,c...

#include #include #include void init(); void getsym(); enum symbol { nul,ident,number,plus,minus,times,slash,oddsym,eql,neq, lss,leq,gtr,geq,lparen,rparen,comma,semicolon,period,becomes, beginsym,endsym,ifsym,thensym,whilesym,writesym,readsym,dosym,callsym, constsym,varsym,procsym,programsym, }; #define norw 14 #define al 10 #define nmax 10 char word [norw][al]; char ch; enum symbol sym; enum symbol wsym[norw]; enum symbol ssym[256]; FILE *fin,*fout; void main() { printf("please input outfile's name:\n"); //词法分析之后的结果要输出到的文件char outname[30],inname[30]; scanf("%s",outname); if((fout=fopen(outname,"w"))==NULL) { printf("cannot open output file!"); exit(0); } printf("please input infile's name:\n"); //需要词法分析的源程序 scanf("%s",inname); if((fin=fopen(inname,"r"))==NULL) { printf("cannot open file!\n"); exit(0); } ch=fgetc(fin); while(ch!=EOF) { getsym(); } } //读取源文件 void getsym() { long m; char id[al+1],a[al+1]; int i,k; init(); if(ch==' '||ch==10||ch==9) { ch=fgetc(fin); } else { if(ch>='a'&&ch<='z'||ch>='A'&&ch<='Z') { k=0; do { if(k='a'&&ch<='z'||ch>='0'&&ch<='9')||(ch>='A'&&ch<='Z'||ch>='0'&&ch<='9')); a[k]=0; strcpy(id,a); for(i=0;i='0'&&ch<='9') { k=0; m=0; sym=number; do { m=10*m+ch-'0'; k++; ch=getc(fin); }while(ch>='0'&&ch<='9'); if(k>=nmax) { printf(" error!数值太大!\n"); //exit(0); } printf("%d number\n",m); fprintf(fout,"%d number\n",m); } else { if(ch==':') { ch=getc(fin); if(ch=='=') { sym=becomes; printf(":= becomes\n"); fprintf(fout,":= becomes\n"); ch=fgetc(fin); } else { sym=nul; printf(": nul\n"); fprintf(fout,": nul\n"); } } { if(ch=='<') { ch=fgetc(fin); if(ch=='=') { sym=leq; printf("<= lep\n"); fprintf(fout,"<= lep\n"); ch=fgetc(fin); } else { sym=lss; printf("< lss\n"); fprintf(fout,"< lss\n"); } } else { if(ch=='>') { ch=fgetc(fin); if(ch=='=') { sym=geq; printf(">= geq\n"); fprintf(fout,">= geq\n"); ch=fgetc(fin); } else { sym=gtr; printf("> gtr\n"); fprintf(fout,"> gtr\n"); } } else { sym=ssym[ch]; if(ch=='+'){printf("+ plus\n");fprintf(fout,"+ plus\n");ch=fgetc(fin);} else if(ch=='-'){printf("- minus\n");fprintf(fout,"- minus\n");ch=fgetc(fin);} else if(ch=='*'){printf("* times\n");fprintf(fout,"* times\n");ch=fgetc(fin);} else if(ch=='/'){printf("/ slash\n");fprintf(fout,"/ slash\n");ch=fgetc(fin);} else if(ch=='('){printf("( lparen\n");fprintf(fout,"( lparen\n");ch=fgetc(fin);} else if(ch==')'){printf(") rparen\n");fprintf(fout,") rparen\n");ch=fgetc(fin);} else if(ch=='='){printf("= eql\n");fprintf(fout,"= eql\n");ch=fgetc(fin);} else if(ch==','){printf(", comma\n");fprintf(fout,", comma\n");ch=fgetc(fin);} else if(ch=='#'){printf("# neq\n");fprintf(fout,"# neq\n");ch=fgetc(fin);} else if(ch=='.'){printf(". period\n");fprintf(fout,". period\n");ch=fgetc(fin);} else if(ch==';'){printf("; semicoln\n");fprintf(fout,"; semicoln\n");ch=fgetc(fin);} else{printf("%c nul\n",ch);fprintf(fout,"%c nul\n",ch);ch=fgetc(fin);} } } } } } } } //对关键字等实现初始化 void init() { int i; for(i=0;i<=255;i++) { ssym[i]=nul; } ssym['+']=plus; ssym['-']=minus; ssym['*']=times; ssym['/']=slash; ssym['(']=lparen; ssym[')']=rparen; ssym['=']=eql; ssym[',']=comma; ssym['.']=period; ssym['#']=neq; ssym[';']=semicolon; strcpy(&(word[0][0]),"begin"); strcpy(&(word[1][0]),"call"); strcpy(&(word[2][0]),"const"); strcpy(&(word[3][0]),"do"); strcpy(&(word[4][0]),"end"); strcpy(&(word[5][0]),"if"); strcpy(&(word[6][0]),"odd"); strcpy(&(word[7][0]),"procedure"); strcpy(&(word[8][0]),"read"); strcpy(&(word[9][0]),"program"); strcpy(&(word[10][0]),"var"); strcpy(&(word[11][0]),"whlie"); strcpy(&(word[12][0]),"write"); strcpy(&(word[13][0]),"then"); wsym[0]=beginsym; wsym[1]=callsym; wsym[2]=constsym; wsym[3]=dosym; wsym[4]=endsym; wsym[5]=ifsym; wsym[6]=oddsym; wsym[7]=procsym; wsym[8]=readsym; wsym[9]=programsym; wsym[10]=varsym; wsym[11]=whilesym; wsym[12]=writesym; wsym[13]=thensym; }

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pl0词法分析器(C语言版)

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