mylex.l

编译原理词法分析器实现四

%{
struct lexvalStack
{
union lex{
   char chr;
   char *str;
   int integer;
   float real;
   double dbl;
   char name[30];
   }lexValue;
char type;
}; 
#include <ctype.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#define false 0
#define ture 1
#include "myyacc.tab.h"
extern int lexVerbose;
extern int linesCount;
char lexeme[30];
char lexlogic[30];
char lexkey[30];
%}
digit	[0-9]
letter	[a-zA-Z]
%%
while	{
			strcpy(lexkey,yytext);
			if(lexVerbose)
				printf("relop:%s\n",lexkey);
			return(K_WHILE);
			}
do	{
			strcpy(lexkey,yytext);
			if(lexVerbose)
				printf("relop:%s\n",lexkey);
			return(K_DO);
			}
begin	{
			strcpy(lexkey,yytext);
			if(lexVerbose)
				printf("relop:%s\n",lexkey);
			return(K_BEGIN);
			}
end	{
			strcpy(lexkey,yytext);
			if(lexVerbose)
				printf("relop:%s\n",lexkey);
			return(K_END);
			}
and 	 	{
			strcpy(lexlogic,yytext);
			if(lexVerbose)
				printf("relop:%s\n",lexlogic);
			return(AND);
			}
or			{
			strcpy(lexlogic,yytext);
			if(lexVerbose)
				printf("relop:%s\n",lexlogic);
			return(OR);
			}
not 		{
			strcpy(lexlogic,yytext);
			if(lexVerbose)
				printf("relop:%s\n",lexlogic);
			return(NOT);
			}
{digit}+\.{digit}*      {
			yylval.real=(float)atof(yytext);
            yylval.lexeme.type=2;
			strcpy(lexeme,yytext);
			if(lexVerbose)
				printf("real:%g\n",yylval.real);
			return(FNUMBER);
			}
{digit}+	{
            yylval.integer=(int)atoi(yytext);
            yylval.lexeme.type=1;
			strcpy(lexeme,yytext);
            if(lexVerbose)
			    printf("int:%d\n",yylval.integer);
            return(INUMBER);
            }
{letter}[A-Za-z0-9_]*	{
			strcpy(lexeme,yytext);
			yylval.lexeme.type=3;
			if(lexVerbose)
				printf("identifier:%s\n",lexeme);
			return(ID);
			}      
\+			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("opterator:%c\n",yylval.chr);
			return('+');
			}
\-			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("oprator:%c\n",yylval.chr);
			return('-');
			}
\*			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("oprator:%c\n",yylval.chr);
			return('*');
			}
\/			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("oprator:%c\n",yylval.chr);
			return('/');
			}
\>			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("oprator:%c\n",yylval.chr);
			return('>');
			}
\<			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("oprator:%c\n",yylval.chr);
			return('<');
			}
"("			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("separator:%c\n",yylval.chr);
			return('(');
			}
")"			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("separtor:%c\n",yylval.chr);
			return(')');
			}
"["			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("separator:%c\n",yylval.chr);
			return('[');
			}
"]"			{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("separtor:%c\n",yylval.chr);
			return(']');
			}
":="			{
			yylval.chr=yytext[0];
			if(lexVerbose)
				printf("evaluator:%c\n",yylval.chr);
			return('=');
			}
";"		{
			yylval.chr=yytext[0];
			if(lexVerbose)
			    printf("separtor:%c\n",yylval.chr);
			return(';');
			}
\n		{
			/*printf("line %d\n",linesCount);
			linesCount++;*/ 			    
			return('\n');
			}

%%
int yywrap()
{
return(1);
}