%{
#include <stdio.h>
%}
 
letter [a-zA-Z]
digit [0-9]
letdigit {letter}|{digit}
 
%%
 
{letter}      { printf("Letter: %c\n", yytext[0]); }
{digit}       { printf("Digit: %c\n", yytext[0]); }
{letdigit}+   { printf("ID: %s\n", yytext); }
\n            { printf("New line character\n"); }
[ ]           { printf("space\n"); }
\'            { printf("single quote\n"); }
.             { /* ignore other characters */ }
 
%%
 
int main() {
    yylex();
    return 0;
}

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