/*** Definition section ***/
 
%{
/* C code to be copied verbatim */
#include <stdio.h>
%}
 
/* This tells flex to read only one input file */
%option noyywrap
 
%%
    /*** Rules section ***/
 
    /* [0-9]+ matches a string of one or more digits */
[0-9]+  {
            /* yytext is a string containing the matched text. */
            printf("Saw an integer: %s\n", yytext);
        }

[a-z][a-z|0-9]+  {
            /* yytext is a string containing the matched text. */
            printf("Saw an identifier: %s\n", yytext);
        }
[*|+|-|/]  {
            /* yytext is a string containing the matched text. */
            printf("Saw an operator: %s\n", yytext);
        }
[=]  {
            /* yytext is a string containing the matched text. */
            printf("Saw an assignment: %s\n", yytext);
        }
 
.|\n    {   /* Ignore all other characters. */   }
 
%%
/*** C Code section ***/
 
int main(void)
{
    /* Call the lexer, then quit. */
    yylex();
    return 0;
}