%option noyywrap %% [ \t] ; [0-9]+(\.[0-9]+)? {yylval=atof(yytext);return NUMBER;} [A-Z] {yylval=(yytext[0]-'A');return VAR;} [a-z] {yylval=(yytext[0]-'a');return VAR;} "pi" {yylval=3.1459;return NUMBER;} "sqrt" return SQRT; "ende" return ENDE; \n|. return yytext[0]; %%