/* A scanner for a toy language: 
   ./lex_yacc/lex4.l 
*/

%{ // Copied verbatim

#include <string.h>
#include <stdlib.h>
#define STRSTART 1
#define STREND 0
#include "y.tab.h"  // tokens are defined 
int line_count = 0; yylType yylval;     
int strFlg = STRSTART; 
 
%}

%option noyywrap
%x CMNT INSTR            

DELIM      ([ \t])
WHITESPACES ({DELIM}+)
P_DIG   ([1-9])
DIG    (0|{P_DIG})
NZ_INT    (0|{P_DIG}{DIG}*)
LOWER      ([a-z])
LETTER     ({LOWER}|[:upper:]|_)
IDENTIFIER ({LETTER}({LETTER}|{DIG})*)

%%

"/*"                    {BEGIN CMNT;}
<CMNT,INSTR>"\""	{
                          if(strFlg == STRSTART){
                             strFlg = STREND;   /* string starts */
                             BEGIN INSTR;
                          }
                          else {
                             strFlg = STRSTART;
                             BEGIN CMNT;       /* string ends */
                          }
                         }
<CMNT,INSTR>.      {;}
<CMNT,INSTR>\n     {++line_count;}
<CMNT>"*/"         {BEGIN INITIAL;}
\n           {
              ++line_count; 
              return (int)'\n';
             }
"\"".*"\""   {
 yylval.string=(char *)malloc((yyleng+1)*(sizeof(char)));
 strncpy(yylval.string, yytext+1, yyleng);
 yylval.string[yyleng-2]='\0';
 return STRNG; 
             }
{WHITESPACES} { ; }
if           {return IF;}
else         {return ELSE; }
while        { return WHILE; }
for          { return FOR; }
int          { return INT; }
\(           { return (int)'('; }
\)           { return (int)')'; }
\{           { return (int)'{'; }
\}           { return (int)'}'; }
;            { return (int)';'; }
,            { return (int)','; }
=            { return (int)'='; }
"<"          { return (int)'<'; }
"+"          { 
               yylval.integer = (int)'+'; 
               return BIN_OP;
             }
"-"          { 
               yylval.integer = (int)'-'; 
               return BIN_OP;
             }
"*"          { 
               yylval.integer = (int)'*'; 
               return BIN_OP;
             }
"/"          { 
               yylval.integer = (int)'/'; 
               return BIN_OP;
              }
{IDENTIFIER} {
  yylval.string=(char *)malloc((yyleng+1)*(sizeof(char)));
  strncpy(yylval.string, yytext, yyleng + 1);
  return ID; 
             } 
{NZ_INT}    { 
               yylval.integer = atoi(yytext); 
               return NUM; 
             }
.            { ; }
%%
/* The function yywrap()  */
//int yywrap(){return 1;}