cminus.l

来自「语法分析器lex和词法分析器yacc的C++语言实现 1.Lex （1）Le」· L 代码 · 共 42 行

%{
#include<iostream>
#include<cstdlib>
#include"yytab.h"
extern SV yyval;
%}
digit [0-9]
letter [a-zA-Z]
id {letter}[{letter}|{digit}]*
num {digit}[1-9]*
%%
int         {return INT; }
long		{return LONG;}
short		{return SHORT;}
for			{return FOR;  }
if			{return IF; }
char		{return CHAR; }
float		{return FLOAT;}
unsigned	{return UNSIGNED;}
double		{return DOUBLE;}
signed		{return SIGNED;}
while		{return WHILE;}
else		{return ELSE;}
{id}        {return IDENTIFIER;}
{num}       {return NUM;}
<			{return LESS;}
>			{return GREAT;}
==			{return EQU;}
!=			{return NE;}
,           {return 30020; }
;			{return 30023; }
{		    {return 30021; }
}		    {return 30022; }
\*			{return 30026; }
+			{return 30024; }
-			{return 30025; }
/			{return 30027; }
=           {return 30028; }
\(			{return 30018; }
\)			{return 30019; }
%%