scanner.l

%option noyywrap
LETTER [a-zA-Z_]
DIGIT [0-9]
WHITE_SPACE [ \t] 
%{
// #  include "parser.tab.h"//该文件由后面的parser.y生成。主要定义了token 的值。和yylval变量
# include <stdio.h>
# include "parser.tab.h"

%}

%% 

"while"     {printf("KEY WORDS: %s \n", yytext); return WHILE; }
"for"       {printf("KEY WORDS: %s \n", yytext); return FOR; }
"if"        {printf("KEY WORDS: %s \n", yytext); return IF; }
"else"      {printf("KEY WORDS: %s \n", yytext); return ELSE; }
"then"      {printf("KEY WORDS: %s \n", yytext); return THEN; }
"printf"    {printf("KEY WORDS: %s \n", yytext); return PRINTF; }
"scanf"     {printf("KEY WORDS: %s \n", yytext); return SCANF; }
"return"    {printf("KEY WORDS: %s \n", yytext); return RETURN; }
"void"      {printf("KEY WORDS: %s \n", yytext); return VOID; }
"\''"       {printf("KEY WORDS: %s \n", yytext); return S_QUO; /* 单引号 */}
"\""        {printf("KEY WORDS: %s \n", yytext); return D_QUO; /* 双引号 */}
"int"       {printf("KEY WORDS: %s \n", yytext); return INT; }
","         {printf("KEY WORDS: %s \n", yytext); return COMMA; }
";"         {printf("KEY WORDS: %s \n", yytext); return SEMI; }
"="         {printf("KEY WORDS: %s \n", yytext); return ASSIGN_OP; }
"("         {printf("KEY WORDS: %s \n", yytext); return '('; }
")"         {printf("KEY WORDS: %s \n", yytext); return ')'; }
"["         {printf("KEY WORDS: %s \n", yytext); return '['; }
"]"         {printf("KEY WORDS: %s \n", yytext); return ']'; }
"{"         {printf("KEY WORDS: %s \n", yytext); return '{'; }
"}"         {printf("KEY WORDS: %s \n", yytext); return '}'; }

{LETTER}([a-zA-Z_]|{DIGIT})*  {yylval.str = strdup(yytext);/*printf("ID: %s\n; ", yytext);*/ return IDENTIFIER;  }


[-]?[1-9]{DIGIT}* {yylval.str = strdup(yytext); /*printf("CONST TYPE: int VALUE: %s\n", yylval.str);*/ return CONST; }


"+"    {/*printf("ALOGRITHM OPERARION: %s \n", yytext);*/ return ADD; /* 加 addition*/}
"-"    {printf("ALOGRITHM OPERARION: %s \n", yytext); return SUB; /* 减 substraction*/}
"*"    {/*printf("ALOGRITHM OPERARION: %s \n", yytext);*/ return MUL; /* 乘 */}
"/"    {printf("ALOGRITHM OPERARION: %s \n", yytext); return DIV; /* 除 */}
"%"    {printf("ALOGRITHM OPERARION: %s \n", yytext); return MOD; /* 取余 */}
"^"    {printf("ALOGRITHM OPERARION: %s \n", yytext); return POW; /* 求幂 */}

"=="   {printf("RELATION OPERARION: %s \n", yytext); return EQ_OP; /*EQual_OPeration*/}
">"    {printf("RELATION OPERARION: %s \n", yytext); return GT_OP; /*Greater_Than_OPeration*/}
"<"    {printf("RELATION OPERARION: %s \n", yytext); return LT_OP; /*Less_Than_OPeration*/}
">="   {printf("RELATION OPERARION: %s \n", yytext); return GE_OP; /*Greater_Equal_OPeration*/}
"<="   {printf("RELATION OPERARION: %s \n", yytext); return LE_OP; /*Less_Equal_OPeration*/}
"!="   {printf("RELATION OPERARION: %s \n", yytext); return NE_OP; /*Not_Equal_OPeraiont*/}

"&&"   {printf("LOGICAL OPERARION: %s \n", yytext); return AND; /*logical_AND_operation*/ }
"||"   {printf("LOGICAL OPERARION: %s \n", yytext); return OR; }
"!"    {printf("LOGICAL OPERARION: %s \n", yytext); return NOT; }

\n     { return EOL; }

[/][*][^*]*[*]+([^*/][^*]*[*]+)*[/]       { /* DO NOTHING */ }
"//"[^\n]*   {/* DO NOTHING */}
{WHITE_SPACE} { /* ignore white space */ }
.       {printf("ERROR!!"); }
%%