%{
#include<stdio.h>
%}
digit​​[0-9]
letter​​[a-zA-Z]
id​​​{letter}({letter}|{digit})*
num​​{digit}+
keyword​begin|end|int|if|while
relop​​<|<=|>|>=|==|!=
arithop ​\-|\+|\*|\/
assign​​=
%%
{keyword}​{printf("keyword:%s\n", yytext);}
{digit} ​{printf("digit :%s\n",yytext);}
{num}​​{printf("number: %s\n", yytext);}
{id}​​{printf("identifier:%s\n", yytext);}
{relop}​{printf("relational op: %s\n", yytext);}
{arithop}​{printf("arith op: %s\n", yytext);}
{assign}​{printf("assignment op: %s\n", yytext);}
%%
int main(int argc, char *argv[])
{
​printf("Enter Something:");
​yylex();
}
 
int yywrap()
{
​return 1;
}
 

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