#ifndef BITSET_H
#define BITSET_H

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>

typedef struct bitset bitset_t;

bitset_t *bitset_alloc(void);

void bitset_free(bitset_t *bs);

/* Ensure it can represent numbers up to at least 'maxbit'. */
void bitset_reserve(bitset_t *bs, size_t maxbit);

/* Set the nth bit. */
void bitset_set(bitset_t *bs, size_t bit);

/* Clear the nth bit. */
void bitset_clear(bitset_t *bs, size_t bit);

/* Test a bit (returns false if out of range). */
bool bitset_get(const bitset_t *bs, size_t bit);

/* Count bits set to 1. */
size_t bitset_count(const bitset_t *bs);

// TODO check if this is needed
/* bs1 |= bs2 with first 'skip' bits ignored */
void bitset_union_with_offset(bitset_t *bs1, const bitset_t *bs2, size_t skip);

/* Shift all bits up by `n` positions (insert n zeros at LSB) */
void bitset_shift_up(bitset_t *bs, size_t n);

/* Shift all bits down by `n` positions (discard LSB) */
void bitset_shift_down(bitset_t *bs, size_t n);

/* Return highest set bit+1, or 0 if empty. */
size_t bitset_max(const bitset_t *bs);

/* Clear all bits. */
void bitset_reset(bitset_t *bs);

/* bs1 |= bs2 */
void bitset_union(bitset_t *bs1, const bitset_t *bs2);

/* Iterate through set bits: returns next bit >= *start,
   or (size_t)-1 if none.  Caller sets *start = 0 to begin. */
size_t bitset_next(const bitset_t *bs, size_t *start);

/* dump the contents of a bitset to the console */
void bitset_dump(const bitset_t *it);
#endif