编译原理课设——词法分析器

#include "stack.h" #include<string.h> const int maxsize=500;//输入程序的总容量 const int retainsize=30;//最大单词的长度 void main() { stack sretain,snum,sidentier,sresult; char input[maxsize],word[retainsize]; int num=0,flag,quanlity; cout<<"请输入基本字的个数!"<<endl; cin>>quanlity; for(int j=0;j<quanlity;j++) { cout<<"第"<<j+1<<"个基本字: "; cin>>word; if(sretain.compare(word,strlen(word))==-1) sretain.pushretain(word,strlen(word)); } cout<<"请输入程序段,以'!'结束!"<<endl; cin.unsetf(ios::skipws); cin>>input[num]; while(input[num]!='!'&&num<maxsize) { num++; cin>>input[num]; } for(int i=0;i<num;) { flag=0; if(input[i]=='+'||input[i]=='='||input[i]==','||input[i]=='('||input[i]==')') { word[flag]=input[i]; flag++; int temp=sretain.compare(word,flag); if(temp==-1) temp=sretain.pushretain(word,flag); sresult.push(word,flag,temp,-1); i++; } else if(input[i]>='0'&&input[i]<='9') { word[flag]=input[i]; flag++; i++; while(input[i]>='0'&&input[i]<='9') { word[flag]=input[i]; flag++; i++; } int temp=snum.compare(word,flag); if(temp==-1) temp=snum.pushnum(word,flag); sresult.push(word,flag,7,temp); } else if(input[i]>='A'&&input[i]<='Z'||input[i]>='a'&&input[i]<='z') { word[flag]=input[i]; flag++; i++; while(input[i]>='A'&&input[i]<='Z'||input[i]>='a'&&input[i]<='z'||input[i]>='0'&&input[i]<='9') { word[flag]=input[i]; flag++; i++; } int temp=sretain.compare(word,flag); if(temp!=-1) sresult.push(word,flag,temp,-1); else { temp=sidentier.compare(word,flag); if(temp==-1) temp=sidentier.pushvar(word,flag,0); sresult.push(word,flag,6,temp); } } else if(input[i]=='*') { word[flag]=input[i]; flag++; i++; if(input[i]=='*') { word[flag]=input[i]; flag++; i++; } int temp=sretain.compare(word,flag); if(temp==-1) temp=sretain.pushretain(word,flag); sresult.push(word,flag,temp,-1); } else if(input[i]=='#'||input[i]=='@')//定义非法字符 { word[flag]=input[i]; flag++; i++; sresult.pushvar(word,flag,1); } else i++; } cout<<"下面是你输入的基本字:"<<endl; sretain.show(0); cout<<endl; cout<<"下面是标志符:"<<endl; sidentier.show(0); cout<<endl; cout<<"下面是常数:"<<endl; snum.show(0); cout<<endl; cout<<"下面是你输入对应的结果:"<<endl; for(i=0;i<num;i++) cout<<input[i]; cout<<endl; sresult.show(1); cout<<endl; cin>>i; }