set.h

常用的数据结构和算法函数库

/*

Copyright (c) 2005, Simon Howard
All rights reserved.

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*/

/**
 * @file set.h
 *
 * @brief Set of values.
 *
 * A set stores a collection of values.  Each value can only exist once in 
 * the set.
 *
 * To create a new set, use @ref set_new.  To destroy a set, use 
 * @ref set_free.
 *
 * To add a value to a set, use @ref set_insert.  To remove a value
 * from a set, use @ref set_remove.
 *
 * To find the number of entries in a set, use @ref set_num_entries.
 *
 * To query if a particular value is in a set, use @ref set_query.
 *
 * To iterate over all values in a set, use @ref set_foreach.
 */

#ifndef ALGORITHM_SET_H
#define ALGORITHM_SET_H

#ifdef __cplusplus
extern "C" {
#endif

/**
 * Represents a set of data.  Created using the set_new function and destroyed
 * using the set_free function.
 *
 * @see set_new
 * @see set_free
 */

typedef struct _Set Set;

/** 
 * Hash function.  Generates a hash key for data to be stored in a set.
 */

typedef unsigned long (*SetHashFunc)(void *data);

/** 
 * Equality function.  Compares two values to determine if they are
 * equivalent.
 */

typedef int (*SetEqualFunc)(void *data1, void *data2);

/**
 * Copy function.  Given a pointer to some data, return a
 * copy of it. Used by @ref set_intersection and @ref set_union.
 */

typedef void *(*SetCopyFunc)(void *data);

/**
 * Set iterator.  Callback function used to iterate over values in a set.
 */

typedef void (*SetIterator)(void *data, void *user_data);

/**
 * Function used to free values stored in a set.  See
 * @ref set_register_free_function.
 */

typedef void (*SetFreeFunc)(void *data);

/**
 * Create a new set.
 *
 * @param hash_func     Hash function used on data in the set .
 * @param equal_func    Compares two values in the set to determine
 *                      if they are equal.
 * @return              A new set.
 */

Set *set_new(SetHashFunc hash_func, SetEqualFunc equal_func);

/**
 * Destroy a set.
 *
 * @param set           The set to destroy.
 */

void set_free(Set *set);

/**
 * Register a function to be called when values are removed from 
 * the set.
 *
 * @param set           The set.
 * @param free_func     Function to call when values are removed from the
 *                      set.
 */

void set_register_free_function(Set *set, SetFreeFunc free_func);

/**
 * Add a value to a set.
 *
 * @param set           The set.
 * @param data          The data to add to the set .
 * @return              Non-zero (true) if the value was added to the set,
 *                      zero (false) if it already exists in the set.
 */

int set_insert(Set *set, void *data);

/**
 * Remove a value from a set.
 *
 * @param set           The set.
 * @param data          The data to remove from the set.
 * @return              Non-zero (true) if the data was found and removed
 *                      from the set, zero (false) if the data was not
 *                      found in the set.
 */

int set_remove(Set *set, void *data);

/** 
 * Query if a particular value is in a set.
 *
 * @param set           The set.
 * @param data          The data to query for.
 * @return              Zero if the data is not in the set, non-zero if the
 *                      data is in the set.
 */

int set_query(Set *set, void *data);

/**
 * Iterate over all values in a set.
 *
 * @param set           The set.
 * @param callback      Callback function to be invoked for each value.
 * @param user_data     Extra data to be passed to the callback function.
 */

void set_foreach(Set *set, SetIterator callback, void *user_data);

/**
 * Retrieve the number of entries in a set
 *
 * @param set           The set.
 * @return              A count of the number of entries in the set.
 */

int set_num_entries(Set *set);

/**
 * Create an array containing all entries in a set.
 *
 * @param set              The set.
 * @return                 An array containing all entries in the set.
 */

void **set_to_array(Set *set);

/**
 * Perform a union of two sets.  
 *
 * @param set1             The first set.
 * @param set2             The second set.
 * @param copy_func        Pointer to a function to use to copy data.
 *                         When values are inserted into the new set, they
 *                         are first copied using the copy function.
 *                         If NULL is passed, no copying is performed and
 *                         the reference from the first set is added.
 * @return                 A new set containing all values which are in the 
 *                         first or second sets. 
 */

Set *set_union(Set *set1, Set *set2, SetCopyFunc copy_func);

/**
 * Perform an intersection of two sets.
 *
 * @param set1             The first set.
 * @param set2             The second set.
 * @param copy_func        Pointer to a function to use to copy data.
 *                         When values are inserted into the new set, they
 *                         are first copied using the copy function.
 *                         If NULL is passed, no copying is performed and
 *                         the reference from the first set is added.
 * @return                 A new set containing all values which are in both
 *                         sets.
 */

Set *set_intersection(Set *set1, Set *set2, 
                      SetCopyFunc copy_func);

#ifdef __cplusplus
}
#endif

#endif /* #ifndef ALGORITHM_SET_H */