%{
#include <stdio.h>
int num_tokens = 0;
%}
 
DIGIT   [0-9]
LETTER  [a-zA-Z]
ID      {LETTER}({LETTER}|{DIGIT})*
NUMBER  {DIGIT}+(\.{DIGIT}+)?
WS      [ \t\n]+
 
%%
 
"if"|"else"|"while"|"int"|"float"|"return" {
    printf("TOKEN: KEYWORD -> %s\n", yytext);
    num_tokens++;
}
 
{ID} {
    printf("TOKEN: IDENTIFIER -> %s\n", yytext);
    num_tokens++;
}
 
{NUMBER} {
    printf("TOKEN: NUMBER -> %s\n", yytext);
    num_tokens++;
}
 
"+"|"-"|"*"|"/"|"="|"=="|"!="|"<"|">" {
    printf("TOKEN: OPERATOR -> %s\n", yytext);
    num_tokens++;
}
 
"{"|"}"|"("|")"|";" {
    printf("TOKEN: PUNCTUATION -> %s\n", yytext);
    num_tokens++;
}
 
{WS}     { /* skip whitespace */ }
 
. {
    printf("TOKEN: UNRECOGNIZED -> %s\n", yytext);
}
 
%%
 
int main() {
    printf("Enter source code (Ctrl+D to end):\n");
    yylex();
    printf("\nTotal tokens found: %d\n", num_tokens);
    return 0;
}
 
int yywrap() {
    return 1;
}
 

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

aW50IG1haW4oKSB7CiAgICBpZiAoeCAmZ3Q7IDUpIHJldHVybiAzLjE0Owp9

int main() {
    if (x > 5) return 3.14;
}