多文件组织词法分析

如果你还在为多文件组织的重复定义烦恼时，就来这里看看吧。

main.cpp

#include"analyse.h"
#include<iostream>
#include<stdio.h>
using namespace std;
string sentence;
int main()
{
    c = ' ';
    i = 0; j = 0; k = 0;
    sentence = "";
	getline(cin,sentence);//输入语句
	getsym(sentence);//得到语句
	return 0;
}

analyse.h

#ifndef ANALYSE_H_INCLUDED
#define ANALYSE_H_INCLUDED

/*
Copyright:MyCompany

Author: JZF

Date:2016-11-02

Description:Provide  functions  to lexical analysis;
*/
#include<iostream>
#include<stdio.h>
#include<string.h>
#include<string>
#include<conio.h>
using namespace std;


extern string sentence;
extern char c;
extern char word[10];
extern char word2[10];
extern int i, k;

static int j;
bool judge_keyword(char word[10]);
bool judge_constant(char word[10]);
bool judge_identifiers(char word[10]);
bool judge_operator(char word[10]);
bool judge_delimiter(char c);
void getsym(string sentence);
#endif // ANALYSE_H_INCLUDED

lexical.cpp

#include "analyse.h"
#include<iostream>
#include<stdio.h>
using namespace std;
char c;
char word[10];
char word2[10];
int i, k;
bool judge_keyword(char word[10])//判断是否为关键字
{
        if (strcmp(word, "begin") == 0)
        {
            cout << "(1,begin)";
        }
        else if (strcmp(word, "if") == 0)
        {
            cout << "(2,if)";
        }
        else if (strcmp(word, "then") == 0)
        {
            cout << "(3,then)";
        }
        else if (strcmp(word, "while") == 0)
        {
            cout << "(4,while)";
        }
        else if (strcmp(word, "do") == 0)
        {
            cout << "(5,do)";
        }
        else if (strcmp(word, "end") == 0)
        {
            cout << "(6,end)";
        }
        else
        {
            return false;
        }
        return true;
}

bool judge_constant(char word[10])//判断是否为常量
{
    c = word[j-1];
    if (c <= '9' && c >= '0')
    {
        k = 0;
        word2[k] = c;
        k++;
        while (word[j] <= '9' && word[j] >= '0')
        {
            word2[k] = word[j];
            j++;
            k++;
        }
        if (word[j] == '.')//判断是否为小数
        {
            j++;
            word2[k] = '.';
            k++;
             while (word[j] <= '9' && word[j] >= '0')
            {
                word2[k] = word[j];
                j++;
                k++;
            }
        }
        word2[k] = '\0';
        cout << "(11," << word2 << ")";
        return true;
    }
    else
        return false;

}

bool judge_identifiers(char word[10])//判断是否为标识符
{
    c = word[j-1];
    if (c <= 'z' && c >= 'a')
    {
        k = 0;
        word2[k] = c;
        k++;
        while ((word[j] <= 'z' && word[j] >= 'a')||(word[j] <= '9' && word[j] >= '0'))
        {
            word2[k] = word[j];
            j++;
            k++;
        }
        word2[k] = '\0';
        cout << "(10," << word2 << ")";
        return true;
    }
    else
        return false;
}

bool judge_operator(char word[10])//判断是否为运算符
{
    c = word[j-1];
    if (c == '+')
    {
        cout << "(13,+)";
    }
    else if (c == '-')
    {
        cout << "(14,-)";
    }
    else if (c == '*')
    {
        cout << "(15,*)";
    }
    else if (c == '/')
    {
        cout << "(16,/)";
    }
    else if (c == ':')
    {
        if (word[j] == '=')
        {
            cout << "(18,:=)";
            j++;
        }
        else
            cout << "(17,:)";
    }
    else if (c == '<')
    {
        if (word[j] == '>')
        {
            cout << "(21,<>)";
        }
        else if (word[j] == '=')
        {
            cout << "(22,<=)";
        }
        else
            cout << "(20,<)";
        j++;
    }
    else if (c == '>')
    {
        if (word[j] == '=')
        {
            cout << "(24,>=)";
            j++;
        }
        else
            cout << "(23,>)";
    }
    else if (c == '=')
    {
        cout << "(25,=)";
    }
    else
    {
        return false;
    }
    return true;
}

bool judge_delimiter(char c)//判断是否为界符
{
    if (c == ';')
    {
        cout << "(26,;)";
    }
    else if (c == '(')
    {
        cout << "(27,()";
    }
    else if (c == ')')
    {
        cout << "(28,))";
    }
    else
    {
        return false;
    }
    return true;
}
void getsym(string sentence)//得到语句
{
    i = 0;
    j = 0;
    k = 0;
	c = sentence[0];
	while (c != '#')
	{
		c = sentence[i];
		word[j] = c;
		i++;
		j++;
		if (c == ' ' || c == '#')//得到一个单词
		{
			word[j-1] = '\0';
            if(judge_keyword(word)){}//判断是否为关键字
			else
			{
			    j = 0;
				c=word[0];
				k = 0;
				while(c != '\0')
				{
					c = word[j];
					j++;
                    if (judge_constant(word)){}//判断是否为常量
                    else if (judge_identifiers(word)){}//判断是否为标识符
                    else if (judge_operator(word)){}//判断是否为运算符
                    else if (judge_delimiter(c)){}//判断是否为界符
				}
			}
			j = 0;//单词初始化
		}
	}
}