1.cpp

编译器第一步

#include <iostream> 
#include <fstream>
#include <string>
#include <memory>
using namespace std;
struct Result                 
{
	string str;
	string ch;
	int pos;
}result[9000];                            
string ID[5000];
string NUM[1000];
int resultNum = 0, IDNum = 0, NUMNum = 0;
int line = 1;
const int KEYNUM = 54;
const int SPECIALNUM = 32;
string keyWord[KEYNUM] = {"asm", "auto", "bool", "break", "case", "catch", "char", "class", 
"const", "continue", "default", "delete", "do", "double", "else", "enum", "extern", 
"false", "float", "for", "friend", "goto", "if", "inline", "int", "long", "namespace", 
"new", "operator", "private", "protected", "public", "register", "return", "short", 
"signed", "sizeof", "static", "struct", "switch", "template", "this", "throw", "true", 
"try", "typedef", "typename", "union", "unsigned", "using", "virtual", "void", "volatile", "while"}; 
string specialWord[SPECIALNUM] = { "+", "++", "-", "--", "*", "/", "%", "!", "?", "=","==", ",", "<", 
									">", "(", ")", "{", "}", "||", "&&", ";","#","<<",">>","_","[","]" , "\"",".","\'","\:","\\"};
ifstream data("data.txt");
ofstream keylist("keyword.txt");
ofstream speciallist("special.txt");
ofstream idlist("identifier.txt");
ofstream numlist("constnumber.txt");
ofstream resultlist("result.txt");
ofstream errer("errer.txt");
int posInKeyWord(const string& str)
{
	for(int i = 0; i < KEYNUM; i++)
	{
		if( keyWord[i] == str )
			return i;
	}
	return -1;	
}
int posInID(const string& str)
{
	for(int i = 0; i < IDNum; i++)
	{
		if( ID[i] == str)
			return i;
	}
	return -1;
}
int posInNUM(const string& str)
{
	for(int i =0; i < NUMNum; i++)
	{
		if(NUM[i] == str)
			return i;
	}
	return -1;
}
int posInSpecialWord(const string& str)
{
	for(int i = 0; i < SPECIALNUM; i++)
	{
		if(specialWord[i] == str)
			return i;
	}
	return -1;
}
void addResult(const string& str, const string& ch, const int& pos)
{
	result[resultNum].str = str;
	result[resultNum].ch = ch;
	result[resultNum].pos = pos;
	resultNum++;
	if(resultNum>9000)
	{
		cout<<"You should expand the resultzone."<<endl;
	}
}
void identifier(const string& str)
{
	if(posInKeyWord(str) != -1)
	{
		addResult(str, "Keyword", posInKeyWord(str) + 1);
	}
	else if(posInID(str) == -1)
	{
		ID[IDNum++] = str;
		addResult(str, "Identifier", IDNum);
	}
	else addResult(str, "Identifier", IDNum);
}
void number(const string& str)
{
	if(posInNUM(str) == -1)
		NUM[NUMNum++] = str;
	addResult(str, "Constnumber", NUMNum);
}
void special(const string& str)
{
	addResult(str, "Special", posInSpecialWord(str) + 1);
}
void stringToNumber(ofstream& outfile, const string& str)
{
	int dotpos = str.find_first_of('.'), intNum = 0, len = str.length(), i = 0;
	float floatNum = 0.0, numAfterDot = 0.0;
	if( dotpos == -1)
	{	
		while(i != len)
		{
			intNum = 10 * intNum + (str[i] - '0');
			i++;
		}
		outfile << intNum << endl;
		
	}
	else 
	{
			while(i != dotpos)
			{
				floatNum = 10 * floatNum + (str[i] - '0');
				i++;
			}
			i = len - 1;
			while(i != dotpos)
			{
				 numAfterDot = (numAfterDot + str[i] - '0') / 10;
				 i--;
			}
			floatNum += numAfterDot;
			outfile << floatNum ;
	}
}
void print()
{
	int i;
	for(i = 0; i < KEYNUM; i++)
	{	
		keylist << i+1 << "---" << keyWord[i] << endl;
	}
	for(i = 0; i < SPECIALNUM; i++)
	{
		speciallist << i + 1 << "---" << specialWord[i] << endl;
	}
	for(i = 0; i < IDNum; i++)
	{
		idlist << i +1 << "---" << ID[i] << endl;
	}
	for(i = 0; i < NUMNum; i++)
	{
		numlist << i + 1 << "---" ;
		stringToNumber(numlist, NUM[i]); 
		numlist	<< endl;
	}
	for(i = 0; i < resultNum; i++)
	{
		if((result[i].str[ 0 ] - '0') * (result[i].str[ 0 ] - '9') <= 0)
		{
			stringToNumber(resultlist, result[i].str);
			resultlist << " --> (" << result[i].ch << ", " << result[i].pos << ")" << endl;
		}
		else resultlist << result[i].str << " --> (" << result[i].ch << ", " << result[i].pos << ")" << endl;
	}
}
int main()
{
	char str[20], ch;
	int i = 0; 
	streampos inpos = data.tellg();
	while(!data.eof())
	{
		i = 0;
		memset(str, '\0', sizeof(str));
		data.get(ch);
		inpos = data.tellg();
		if(ch == ' ' || ch =='\n' || ch == '\t')
		{
			while(ch == ' ' || ch == '\n' || ch == '\t')
			{
				if(ch == '\n')
					line++;
				data.get(ch);
				if(data.eof())
					break;
				inpos = data.tellg();
			}
			if(data.eof())
				break;
			data.seekg(-1, ios::cur);
		}
		else if( (ch - 'a') * (ch - 'z') <= 0 || (ch - 'A') *(ch - 'Z') <= 0 )
		{
			while((ch - 'a') * (ch - 'z') <= 0 || (ch - 'A') *(ch - 'Z') <= 0 || (ch - '0') * (ch - '9') <= 0)
			{
				str[i++] = ch;
				data.get(ch);
				inpos = data.tellg();
			}
			identifier(str);			
			data.seekg(-1,ios::cur);
			inpos = data.tellg();
		}
		else if((ch - '0') * (ch - '9') <= 0)
		{
			while((ch - '0') * (ch - '9') <= 0 || ch == '.')
			{
				str[i++] = ch;
				data.get(ch);
				if(data.eof())
					break;
				inpos = data.tellg();
			}
			number(str);
			if(data.eof())
				break;
			data.seekg(-1, ios::cur);
			inpos = data.tellg();
		}
		else if(ch == '+')
		{
			str[i++] = ch;
			data.get(ch);
			if(ch == '+')
			{
				str[i] = ch;
				special(str);
			}
			else{
				data.seekg(-1, ios::cur);
			special(str);
			}
		}
		else if(ch == '-')
		{
			str[i++] = ch;
			data.get(ch);
			if(ch == '-')
			{
				str[i] = ch;
				special(str);
			}
			else{
				data.seekg(-1, ios::cur);
			special(str);
			}
		}
		else if(ch == '?')
		{
			str[i++] = ch;
			special(str);
		}
		else if(ch == '|')
		{
			str[i++] = ch;
			
			special(str);
		}
		else if(ch == '&')
		{
			str[i++] = ch;
			special(str);
		}
		else if(ch == '=')
		{
			str[i++] = ch;
			data.get(ch);
			if(ch == '=')
			{
				str[i] = ch;
				special(str);
			}
			else
			{
				special(str);
				data.seekg( -1, ios::cur);
			}
		}
		else if(ch == '#')
		{
			str[i++] = ch;					
			special(str);
		}
		else if(ch == '_')
		{
			str[i++] = ch;					
			special(str);
		}
		else if(ch == '[')
		{
			str[i++] = ch;					
			special(str);
		}
		else if(ch == ']')
		{
			str[i++] = ch;					
			special(str);
		}
		else if(ch=='\"')
		{
			str[i++] = ch;					
			special(str);
		}
		else if(ch=='.')
		{
			str[i++] = ch;					
			special(str);
		}
		else if(ch=='\'')
		{
			str[i++] = ch;					
			special(str);
		}
		else if(ch=='\:')
		{
			str[i++] = ch;					
			special(str);
		}
		else if(ch=='\\')
		{
			str[i++] = ch;					
			special(str);
		}

		else if(ch == '>')
		{
			str[i++] = ch;
			data.get(ch);
			if(ch == '>')
			{
				str[i] = ch;
				special(str);
			}
			else
			{
				special(str);
				data.seekg(-1, ios::cur);
			}
		}
		else if(ch == '<')
		{
			str[i++] = ch;
			data.get(ch);
			if(ch == '<')
			{
				str[i] = ch;
				special(str);
			}
			else {
				special(str);
				data.seekg(-1, ios::cur);
			}
		}
		else if (ch == '*' || ch == '/' || ch == '%' || ch == '!' || ch == ',' || ch == '(' || ch == ')' || ch == '{' || ch == '}' || ch == ';')
		{
			str[0] = ch;
			special(str);		
		}
		else 
		{
			errer << "error in line " << line << " : there is something we can't deal with :" <<ch<< endl;
		}

	}
	print();
	return 0;
}