#ifndef BITEVEC_H_
#define BITEVEC_H_

#ifdef __cplusplus
extern "C" {
#endif

struct bitvec {
    //storage for the bits
    unsigned long *vec;
    //length of the above vec. (Not the number of bits !)
    size_t vec_len;
};

/**
 *  Evaluates the length required for a bitvec to store nbit bits.
 */
#define BITVEC_VEC_LEN(nbits)   ((nbits/(sizeof(unsigned long)*CHAR_BIT)) + (nbits % (sizeof(unsigned long)*CHAR_BIT) == 0 ? 0 : 1))

/**
 * Use as :
 * unsigned long v[10];
 * struct bitvec v = BITVEC_STATIC_INIT(v);
 */
#define BITVEC_STATIC_INIT(vec_data)\
{\
vec_data,\
sizeof vec_data/sizeof vec_data[0]}


/**
 * Returns a newly malloced bitvec, capable of storing at least nbits bits
 * All bits are initially zero.
 *
 */
struct bitvec *bitvec_new(size_t nbits);

/** free a bitvec previously allocated by bitvec_new
 */
void bitvec_free(struct bitvec *v);

//Note that accessing a bit beyond the nbits originally initialized
//for the given bitvec is undedefined

/** Sets bit no. b */
void set_bit(struct bitvec *v,int b);

/** Clears bit no. b*/
void clear_bit(struct bitvec *v,int b);

/** Gets the current value (0 or 1) of bit no. b*/
int get_bit(const struct bitvec *v,int b);

/** Sets all bits to zero */
void clear_all(struct bitvec *v);

/** Sets all bits to one */
void set_all(struct bitvec *v);

/** Initialize bits from a array of ints, each array element maps to one bit.
 * The bits are initialized from the int array so zero maps to zero and non-zero maps to one.
 * e..g to set the 5 first bits, to 01110:
 * int a[] = {0,1,1,1,0};
 * set_bits_from_array(v,a,5);
 * */
void set_bits_from_array(struct bitvec *v,char *array,size_t array_len);

// The _s ("secure") versions does boundary checking and assert() if they
// try to access a bit out of bounds.

void set_bit_s(struct bitvec *v,int b);

void clear_bit_s(struct bitvec *v,int b);

int get_bit_s(const struct bitvec *v,int b);

#ifdef __cplusplus
}
#endif

#endif