Implementation of wc in Flex

wc.l

/* -*-bison-*- */
/* Simple wc implementation in Flex */
%option noyywrap

			int rows = 0, words = 0, chars = 0;

%%
\n		rows++;
[A-Za-z0-9]+	words++; chars += strlen(yytext);
.		chars++;
%%

int main() {
    yylex();
    printf("\t%d\t%d\t%d\n", rows, words, chars);
    return 0;
}

Previous revision attempted to emulate the workings of the Unix wc program by (incorrectly) assuming that rules in Flex are pass-through rules. This revision works better, but it does not use pass-through. Instead, it increments chars by the calculated length of the matched token.