%{
#include <stdio.h>
#include <ctype.h>

// Declare tokens
#define IDENTIFIER 1
#define INTEGER 2
#define FLOAT 3
#define KEYWORD 4
#define OPERATOR 5
#define PARENTHESIS 6

void yyerror(const char *msg);
%}

%%

/* Keywords */
"var"        { printf("KEYWORD: var\n"); return KEYWORD; }
"if"         { printf("KEYWORD: if\n"); return KEYWORD; }
"then"       { printf("KEYWORD: then\n"); return KEYWORD; }
"else"       { printf("KEYWORD: else\n"); return KEYWORD; }
"begin"      { printf("KEYWORD: begin\n"); return KEYWORD; }
"end"        { printf("KEYWORD: end\n"); return KEYWORD; }
"or"         { printf("KEYWORD: or\n"); return KEYWORD; }
"and"        { printf("KEYWORD: and\n"); return KEYWORD; }

/* Identifiers */
[a-zA-Z_][a-zA-Z0-9_]* { printf("IDENTIFIER: %s\n", yytext); return IDENTIFIER; }

/* Numbers */
[0-9]+ { printf("INTEGER: %s\n", yytext); return INTEGER; }
[0-9]+"."[0-9]+ { printf("FLOAT: %s\n", yytext); return FLOAT; }

/* Arithmetic operators */
"+"|"-"|"*"|"/" { printf("OPERATOR: %s\n", yytext); return OPERATOR; }

/* Parentheses */
"(" { printf("PARENTHESIS: %s\n", yytext); return PARENTHESIS; }
")" { printf("PARENTHESIS: %s\n", yytext); return PARENTHESIS; }

/* Ignore whitespace */
[ \t\n]+      { /* ignore whitespace */ }

/* Error handling */
.             { printf("Unknown character: %s\n", yytext); }

%%

int yywrap() {
    return 1;
}

void yyerror(const char *msg) {
    fprintf(stderr, "%s\n", msg);
}

int main() {
    yylex();
    return 0;
}