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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
/**
 * \file list.h
 * \brief Interface for list implementations.
 * \author Mike Becker
 * \author Olaf Wintermann
 * \version 3.0
 * \copyright 2-Clause BSD License
 */

#ifndef UCX_LIST_H
#define UCX_LIST_H

#include <stdlib.h>
#include "allocator.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * A comparator function comparing two list elements.
 */
typedef int(*CxListComparator)(void const *left, void const *right);

/**
 * Internal type for the list structure - use CxList instead.
 */
typedef struct cx_list_s cx_list_s;

/**
 * The class definition for arbitrary lists.
 */
typedef struct {
    /**
     * Member function for adding an element.
     */
    int (*add)(cx_list_s *list, void *elem);

    /**
     * Member function for inserting an element.
     */
    int (*insert)(cx_list_s *list, size_t index, void *elem);

    /**
     * Member function for removing an element.
     */
    int (*remove)(cx_list_s *list, size_t index);

    /**
     * Member function for element lookup.
     */
    void *(*at)(cx_list_s *list, size_t index);

    /**
     * Member function for finding an element.
     */
    size_t (*find)(cx_list_s *list, void *elem);

    /**
     * Member function for retrieving the last element.
     */
    void *(*last)(cx_list_s *list);
} cx_list_class;

/**
 * Structure for holding the base data of a list.
 */
struct cx_list_s {
    /**
     * The list class definition.
     */
    cx_list_class *cl;
    /**
     * The allocator to use.
     */
    CxAllocator allocator;
    /**
     * The comparator function for the elements.
     */
    CxListComparator cmpfunc;
    /**
     * The size of each element (payload only).
     */
    size_t itemsize;
    /**
     * The size of the list (number of currently stored elements).
     */
    size_t size;
    /**
     * The capacity of the list (maximum number of elements).
     */
    size_t capacity;
};

/**
 * Common type for all list implementations.
 */
typedef cx_list_s *CxList;

/**
 * Adds an item to the end of the list.
 *
 * \remark It is implementation defined whether
 * the contents of the element are copied or the
 * pointer is added to the list. In the latter case
 * the \c itemsize of the list SHALL be \c sizeof(void*).
 *
 * @param list the list
 * @param elem a pointer to the element to add
 * @return zero on success, non-zero on memory allocation failure
 */
int cxListAdd(CxList list, void *elem);

/**
 * Inserts an item at the specified index.
 *
 * If \p index equals the list \c size, this is effectively cxListAdd().
 *
 * \remark It is implementation defined whether
 * the contents of the element are copied or the
 * pointer is added to the list. In the latter case
 * the \c itemsize of the list SHALL be \c sizeof(void*).
 *
 * @param list the list
 * @param index the index the element shall have
 * @param elem a pointer to the element to add
 * @return zero on success, non-zero on memory allocation failure
 * or when the index is out of bounds
 */
int cxListInsert(CxList list, size_t index, void *elem);

/**
 * Removes the element at the specified index.
 * @param list the list
 * @param index the index of the element
 * @return zero on success, non-zero if the index is out of bounds
 */
int cxListRemove(CxList list, size_t index);

/**
 * Returns a pointer to the element at the specified index.
 *
 * @param list the list
 * @param index the index of the element
 * @return a pointer to the element or \c NULL if the index is out of bounds
 */
void *cxListAt(CxList list, size_t index);

/**
 * Returns the index of the first element that equals \p elem.
 *
 * Determining equality is performed by the list's comparator function.
 *
 * @param list the list
 * @param elem the element to find
 * @return the index of the element or \c (size+1) if the element is not found
 */
size_t cxListFind(CxList list, void *elem);

/**
 * Returns a pointer to the last element of the list.
 *
 * This is effectively the same as cxListAt() with \c index=size-1, but
 * this implementation may be more efficient depending on the list structure
 * and the conrecte implementation of cxListAt().
 *
 * @param list the list
 * @return a pointer to the last element or \c NULL if the list is empty
 */
void *cxListLast(CxList list);

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* UCX_LIST_H */