option noyywrap bison-bridge bison-locations include stdio include std

%option noyywrap bison-bridge bison-locations
%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define TAG_STRING 1
#define TAG_NUMBER 2
#define TAG_IDENT 3



char *tag_names[] = 
{
  "END_OF_PROGRAM", "STRING", "NUMBER", "IDENT" 
};

struct Position
{
  int line , pos , index ;
};

void print_pos ( struct Position *p )
{
  printf("(%d,%d)" ,p->line, p->pos);
}

struct Fragment
{
  struct Position starting , following;
};

typedef struct Fragment YYLTYPE;

void print_frag ( struct Fragment *f )
{
  print_pos (&(f->starting));
  printf ("-");
  print_pos(&(f->following));
}

union Token {
    char *ident; 
    float num;
    char *st2;
};

typedef union Token YYSTYPE; 

int continued;
struct Position cur;

#define YY_USER_ACTION					\
{										\
    int i;								\
    if (! continued)					\
        yylloc->starting = cur;			\
    continued = 0;						\
										\
    for (i = 0; i < yyleng; i++)		\
    {									\
        if (yytext[i] == '\n')			\
        {								\
            cur.line++;					\
            cur.pos = 1;				\
        }								\
        else							\
            cur.pos++;					\
        cur.index++;					\
    }									\
										\
    yylloc->following = cur;			\
}

void init_scanner(char *program)
{
  continued = 0;
  cur.line = 1;
  cur.pos =1;
  cur.index = 0;
  yy_scan_string(program);
}

void err(char *msg)
{
  printf("Error ");
  print_pos(&cur);
  printf(": %s\n",msg);
}
%}

SPACE [\n\t ]+
STRING \'([^']|\'{2})+\'
DIGIT (\-)?[0-9]+(\.[0-9]+)?
IDENT [a-zA-Z]([a-zA-Z]*(\.)*[0-9]*)+

%x STRINGG STRINGG_IN

%%
{SPACE}

{DIGIT}				{
						yylval->num = atof(yytext);
						return TAG_NUMBER;
					}

{IDENT}				{
						yylval->ident = yytext; 
						return TAG_IDENT;
					}

\'					{BEGIN(STRINGG); continued = 1;yylval->st2 = (char*) malloc (1000);}

<STRINGG>\\\n		err ("unexpected \n, expected ' ");

<STRINGG>[^']* 		{	
				continued = 1;
				yylval->st2 = strcat (yylval->st2, yytext);
			}

<STRINGG>\'\'		{	
				continued = 1;
				yylval->st2 = strcat (yylval->st2, yytext);
			}

<STRINGG>\'			{	
					
				yylval->st2 = strcat (yylval->st2, yytext);
						BEGIN(0);
						return TAG_STRING;
					}
<STRINGG><<EOF>> 	{
						err("end of program found, ' expected");
						return 0;
					}

. 					err("unexpected character");

%%

#define PROGRAM "'sfg''df' % dg435..2 -1.3"

int main ()
{
  int tag;
  YYSTYPE value;
  YYLTYPE coords;
  init_scanner (PROGRAM);
  do
  {
    tag = yylex (&value ,&coords);
    if (tag != 0)
    {
      print_frag(&coords);
      if (tag == 1) {
	printf(" %s \'%s\n", tag_names[tag], value.st2);
        free (value.st2);			
      } else {
	if (tag == 2 ) {
	  printf(" %s %f\n", tag_names[tag], value.num);					
	} else {
	  printf(" %s %s\n", tag_names[tag], value.ident);				
	}
      }
    }
  }
  while ( tag != 0);
  return 0;
}