编译原理实验二 使用lex创建词法分析器

实验二直接上代码吧，其实我也不怎么知道哪里是致命的，课上听老师的课后，将代码写上，但是运行在环境里面还是不行，把注释去掉就可以了，不知道会不会是注释的问题

%{

#include <stdio.h>
#include "define.h"

int lineno = 1;	
TokenType id2keyword(const char* token);

%}

newline		\n
whitespace	[ \t]+
id  [a-zA-Z_]+[a-zA-Z0-9_]*
num ([1-9]+[0-9]*)|([1-9])|0 

%%

":="			{ return ASSIGN; }
"="				{ return EQ;}
"<"				{ return LT; }
"+"				{ return PLUS; }
"-"				{ return MINUS; }
"*"				{ return TIMES; }
"/"				{ return OVER; }
"("				{ return LPAREN; }
")"				{ return RPAREN; }
";"				{ return SEMI; }
{id}            { 
                 	return id2keyword(yytext);
                 } 
{num}           { return NUM; } 

{newline}		{ lineno++; }
{whitespace}	{  }

"{"				{
				
					
					
					char c;
					do
					{
						c = input();
						if(c == EOF)
						{
							return ERROR;
						}
						else if(c == '\n')
							lineno++;
						else if(c == '}')
							break;
					}while(1);
					

				}
				
.				{ return ERROR; }


%%


void printToken(TokenType token,char* tokenString);


int main(int argc, char* argv[])
{
	TokenType tt;
	

	if(argc < 2)
	{
		printf("Usage: scan.exe filename.\n");
		return 1;
	}

	FILE* file = fopen(argv[1], "rt");
	if(NULL == file)
	{
		printf("Can not open file \"%s\".\n", argv[1]);
		return 1;
	}
	

	yyin = file;
	
	
	while((tt = yylex()) != 0)
	{
			
		printToken(tt, yytext);
		if(tt==ERROR)
		break;
	}
	
		fclose(file);	
	
	return 0;
}


typedef struct _KeyWord_Entry
{
	const char* word;
	TokenType type;
}KeyWord_Entry;

static const KeyWord_Entry key_table[] =
{
	{ "if", 	IF 		},
    { "then",	THEN	},
    { "else",	ELSE	},
    { "end",	END		},
    { "repeat",	REPEAT	},
    { "until",	UNTIL	},
    { "read",	READ	},
    { "write", WRITE     }
};


TokenType id2keyword(const char* id)
{
	int i;
	for (i = 0; i < 8; i++)
	{
		if (!strcmp(id, key_table[i].word))
			return key_table[i].type;
			
		
	}
	return ID;

}


void printToken(TokenType token,char* tokenString)
{
	switch (token)
	{
	    
		case IF:        
			printf("line%2d:  %-6d%-10s%s\n", lineno,IF,"IF", "if");
			break;
		case THEN:     
			printf("line%2d:  %-6d%-10s%s\n", lineno,THEN, "THEN","then");
			break;
		case ELSE:        
			printf("line%2d:  %-6d%-10s%s\n",lineno, ELSE, "ELSE" "else");
			break;
		case END:       
			printf("line%2d:  %-6d%-10s%s\n", lineno,END,"END", "end");
			break;
		case REPEAT:     
			printf("line%2d:  %-6d%-10s%s\n", lineno,REPEAT,"REPEAT", "repeat");
			break;
		case UNTIL:      
			printf("line%2d:  %-6d%-10s%s\n", lineno,UNTIL,"UNTIL", "until");
			break;
		case READ:       
			printf("line%2d:  %-6d%-10s%s\n",lineno, READ,"READ", "read");
			break;
		case WRITE:       
			printf("line%2d:  %-6d%-10s%s\n",lineno, WRITE, "WRITE", "write");
			break;
		case ASSIGN:      
			printf("line%2d:  %-6d%-10s%s\n",lineno, ASSIGN,"ASSIGN", ":=");
			break;
		case LT:          
			printf("line%2d:  %-6d%-10s%s\n",lineno, LT,"LT", "<");
			break;
		case EQ:           
			printf("line%2d:  %-6d%-10s%s\n", lineno,EQ, "EQ","=");
			break;
		case LPAREN:        
			printf("line%2d:  %-6d%-10s%s\n", lineno,LPAREN," LPAREN" ,"(");
			break;
		case RPAREN:        
			printf("line%2d:  %-6d%-10s%s\n", lineno,RPAREN,"RPAREN", ")");
			break;
		case SEMI:        
			printf("line%2d:  %-6d%-10s%s\n", lineno,SEMI,"SEMI", ";");
			break;
		case PLUS:       
			printf("line%2d:  %-6d%-10s%s\n", lineno,PLUS, "PLUS","+"); 
			break;
		case MINUS:       
			printf("line%2d:  %-6d%-10s%s\n", lineno,MINUS, "MINUS","-");
			break;
		case TIMES:       
			printf("line%2d:  %-6d%-10s%s\n", lineno,TIMES, "TIMES","*");
			break;
		case OVER:         
			printf("line%2d:  %-6d%-10s%s\n", lineno,OVER,"OVER", "/");
			break;
		case ENDFILE:       
			printf("line%2d:  %-6d%-10s%s\n", lineno,ENDFILE,"ENDFILE", "endfile");
			break;
		case NUM: 
			printf("line%2d:  %-6d%-10s%s\n", lineno,NUM,"NUM", tokenString);
			break;
		case ID:  
			printf("line%2d:  %-6d%-10s%s\n", lineno,ID, "ID",tokenString);
			break;
         case ERROR:  
			printf("line%2d:  %-6d%-10s\n", lineno,ERROR, "ERROR");
			break;
		default: return ;
			

	}
}