%{
#include <stdio.h>
#include <math.h>
extern int lineno;

/*
simple AG based on Knuth example 1.3
*/

%}
%union{
  struct {
    float value;
    int len;
  } ival;
}

%token <ival>
ZERO
ONE
RADIXPOINT

%type <ival>
bit
bitlist
binaryfloat

%start binaryfloat

%%
bit           : ZERO
{
  $$.value = 0.;
};

bit           : ONE
{
  $$.value = 1.;
};

bitlist       : bit
{
  $$.value = $1.value;
  $$.len = 1;
};

bitlist       : bitlist bit
{
  $$.value = 2*$1.value +$2.value;
  $$.len = $1.len + 1;
};

binaryfloat : bitlist
{ 
  $$.value = $1.value;
  printf("value is %f\n",$$.value);
} 
;

binaryfloat : bitlist RADIXPOINT bitlist
{
  $$.value = $1.value + $3.value/pow(2., (0.0 + $3.len));
  printf("length of fractional part is %d\n", $3.len);
  printf("value is %f\n",$$.value);
};

%%