'Scanner'没有在g ++中命名类型错误 [英] 'Scanner' does not name a type error in g++
问题描述
我试图在g ++中编译代码,并得到以下错误:
在scanner.hpp包含的文件中:8,
从scanner.cpp:5:
parser.hpp:14:错误:'扫描器'不命名类型
parser.hpp:15:错误:'Token'不命名类型
这是我的g ++命令:
g ++ parser.cpp scanner.cpp -Wall
这里是parser.hpp:
#ifndef PARSER_HPP
# define PARSER_HPP
#include< string>
#include< map>
#includescanner.hpp
using std :: string;
类解析器
{
//成员变量
private:
Scanner lex; //词法分析器
令牌看//跟踪当前的前瞻标记
//成员函数
< some function declarations>
};
#endif
这里是scanner.hpp:
#ifndef SCANNER_HPP
#define SCANNER_HPP
#include< iostream>
#include< cctype>
#include< string>
#include< map>
#includeparser.hpp
using std :: string;
使用std :: map;
enum
{
//保留字
BOOL,ELSE,IF,TRUE,WHILE,DO,FALSE,INT,VOID,
标点和运算符
LPAREN,RPAREN,LBRACK,RBRACK,LBRACE,RBRACE,SEMI,COMMA,PLUS,MINUS,TIMES,
DIV,MOD,AND,OR,NOT,IS,ADDR,EQ,NE ,LT,GT,LE,GE,
//符号常量
NUM,ID,ENDFILE,ERROR
};
class Token
{
public:
int tag;
int value;
string lexeme;
Token(){tag = 0;}
Token(int t){tag = t;}
};
类Num:public Token
{
public:
Num(int v){tag = NUM; value = v;}
};
类Word:public Token
{
public:
Word(){tag = 0; lexeme =default;}
Word(int t,string l){tag = t; lexeme = l;}
};
类扫描器
{
private:
int line; //编译器当前所在的行
int depth; //在解析树中有多深,编译器是
map< string,Word>话; //保留字列表和使用的标识符
//成员函数
public:
Scanner();
Token scan();
string printTag(int);
friend class Parser;
};
#endif
任何人都看到问题?我觉得我缺少一些非常明显的东西。
parser.hpp incluser scanner.hpp,反之亦然。
所以一个文件在另一个文件之前。
您可以使用
或重新标记标题
I'm trying to compile code in g++ and I get the following errors:
In file included from scanner.hpp:8,
from scanner.cpp:5:
parser.hpp:14: error: ‘Scanner’ does not name a type
parser.hpp:15: error: ‘Token’ does not name a type
Here's my g++ command:
g++ parser.cpp scanner.cpp -Wall
Here's parser.hpp:
#ifndef PARSER_HPP
#define PARSER_HPP
#include <string>
#include <map>
#include "scanner.hpp"
using std::string;
class Parser
{
// Member Variables
private:
Scanner lex; // Lexical analyzer
Token look; // tracks the current lookahead token
// Member Functions
<some function declarations>
};
#endif
and here's scanner.hpp:
#ifndef SCANNER_HPP
#define SCANNER_HPP
#include <iostream>
#include <cctype>
#include <string>
#include <map>
#include "parser.hpp"
using std::string;
using std::map;
enum
{
// reserved words
BOOL, ELSE, IF, TRUE, WHILE, DO, FALSE, INT, VOID,
// punctuation and operators
LPAREN, RPAREN, LBRACK, RBRACK, LBRACE, RBRACE, SEMI, COMMA, PLUS, MINUS, TIMES,
DIV, MOD, AND, OR, NOT, IS, ADDR, EQ, NE, LT, GT, LE, GE,
// symbolic constants
NUM, ID, ENDFILE, ERROR
};
class Token
{
public:
int tag;
int value;
string lexeme;
Token() {tag = 0;}
Token(int t) {tag = t;}
};
class Num : public Token
{
public:
Num(int v) {tag = NUM; value = v;}
};
class Word : public Token
{
public:
Word() {tag = 0; lexeme = "default";}
Word(int t, string l) {tag = t; lexeme = l;}
};
class Scanner
{
private:
int line; // which line the compiler is currently on
int depth; // how deep in the parse tree the compiler is
map<string,Word> words; // list of reserved words and used identifiers
// Member Functions
public:
Scanner();
Token scan();
string printTag(int);
friend class Parser;
};
#endif
anyone see the problem? I feel like I'm missing something incredibly obvious.
parser.hpp incluser scanner.hpp and vice versa.
So one file evalated before the other.
You can use a forward declaration like
class Scanner;
or reorginaze your headers
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