%{
    #include <stdio.h>
    #include <string.h>
    #include "y.tab.h"
    int line=1;
%}

%start COMMENT
%%
<INITIAL>"quit" exit(0);
<INITIAL>"how_many_line" {fprintf(stderr, "%d lines are read.\n", line);return HOW_MANY_LINE;};
<INITIAL>"("        return LP;
<INITIAL>")"        return RP;
<INITIAL>"+"        return ADD;
<INITIAL>"-"        return SUB;
<INITIAL>"*"        return MUL;
<INITIAL>"/"        return DIV;
<INITIAL>"%"        return MOD;
<INITIAL>[1-9][0-9]* {sscanf(yytext,"%d",&yylval);return INT_LITERAL;};
<INITIAL>[A-Za-z_][A-Za-z_0-9]* {sscanf(yytext,"%s",&yylval);return STR;};
<INITIAL>[0-9]*\.[0-9]* ;
<INITIAL>[ \t] ;
<INITIAL>[\n\r]|\r\n {line++;return NL;};
<INITIAL>^# BEGIN COMMENT;
<INITIAL>. fprintf(stderr, "Please input 'quit' to finish the program.\n");
<COMMENT>\n|\r|\r\n BEGIN INITIAL;
<COMMENT>.      ;
%%