scummvm/common/list.h
2021-04-15 21:20:36 +02:00

300 lines
7.4 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#ifndef COMMON_LIST_H
#define COMMON_LIST_H
#include "common/list_intern.h"
namespace Common {
/**
* @defgroup common_list Lists
* @ingroup common
*
* @brief API for managing doubly linked lists.
*
*
* @{
*/
/**
* Simple doubly linked list, modeled after the list template of the standard
* C++ library.
*/
template<typename t_T>
class List {
protected:
typedef ListInternal::NodeBase NodeBase; /*!< @todo Doc required. */
typedef ListInternal::Node<t_T> Node; /*!< An element of the doubly linked list. */
NodeBase _anchor; /*!< Pointer to the position of the element in the list. */
public:
typedef ListInternal::Iterator<t_T> iterator; /*!< List iterator. */
typedef ListInternal::ConstIterator<t_T> const_iterator; /*!< Const-qualified list iterator. */
typedef t_T value_type; /*!< Value type of the list. */
typedef uint size_type; /*!< Size type of the list. */
public:
/**
* Construct a new empty list.
*/
List() {
_anchor._prev = &_anchor;
_anchor._next = &_anchor;
}
List(const List<t_T> &list) { /*!< Construct a new list as a copy of the given @p list. */
_anchor._prev = &_anchor;
_anchor._next = &_anchor;
insert(begin(), list.begin(), list.end());
}
~List() {
clear();
}
/**
* Insert an @p element before @p pos.
*/
void insert(iterator pos, const t_T &element) {
insert(pos._node, element);
}
/**
* Insert elements from @p first to @p last before @p pos.
*/
template<typename iterator2>
void insert(iterator pos, iterator2 first, iterator2 last) {
for (; first != last; ++first)
insert(pos, *first);
}
/**
* Delete the element at location @p pos and return an iterator pointing
* to the element after the one that was deleted.
*/
iterator erase(iterator pos) {
assert(pos != end());
return iterator(erase(pos._node)._next);
}
/**
* Delete the element at location @p pos and return an iterator pointing
* to the element before the one that was deleted.
*/
iterator reverse_erase(iterator pos) {
assert(pos != end());
return iterator(erase(pos._node)._prev);
}
/**
* Delete the elements between @p first and @p last (including @p first but not
* @p last). Return an iterator pointing to the element after the one
* that was deleted (that is, @p last).
*/
iterator erase(iterator first, iterator last) {
NodeBase *f = first._node;
NodeBase *l = last._node;
while (f != l)
f = erase(f)._next;
return last;
}
/**
* Remove all elements that are equal to @p val from the list.
*/
void remove(const t_T &val) {
NodeBase *i = _anchor._next;
while (i != &_anchor)
if (val == static_cast<Node *>(i)->_data)
i = erase(i)._next;
else
i = i->_next;
}
/** Insert an @p element at the start of the list. */
void push_front(const t_T &element) {
insert(_anchor._next, element);
}
/** Append an @p element to the end of the list. */
void push_back(const t_T &element) {
insert(&_anchor, element);
}
/** Remove the first element of the list. */
void pop_front() {
assert(!empty());
erase(_anchor._next);
}
/** Remove the last element of the list. */
void pop_back() {
assert(!empty());
erase(_anchor._prev);
}
/** Return a reference to the first element of the list. */
t_T &front() {
return static_cast<Node *>(_anchor._next)->_data;
}
/** Return a reference to the first element of the list. */
const t_T &front() const {
return static_cast<Node *>(_anchor._next)->_data;
}
/** Return a reference to the last element of the list. */
t_T &back() {
return static_cast<Node *>(_anchor._prev)->_data;
}
/** Return a reference to the last element of the list. */
const t_T &back() const {
return static_cast<Node *>(_anchor._prev)->_data;
}
/** Assign a given @p list to this list. */
List<t_T> &operator=(const List<t_T> &list) {
if (this != &list) {
iterator i;
const iterator e = end();
const_iterator i2;
const_iterator e2 = list.end();
for (i = begin(), i2 = list.begin(); (i != e) && (i2 != e2); ++i, ++i2) {
static_cast<Node *>(i._node)->_data = static_cast<const Node *>(i2._node)->_data;
}
if (i == e)
insert(i, i2, e2);
else
erase(i, e);
}
return *this;
}
/** Return the size of the list. */
size_type size() const {
size_type n = 0;
for (const NodeBase *cur = _anchor._next; cur != &_anchor; cur = cur->_next)
++n;
return n;
}
/** Remove all elements from the list. */
void clear() {
NodeBase *pos = _anchor._next;
while (pos != &_anchor) {
Node *node = static_cast<Node *>(pos);
pos = pos->_next;
delete node;
}
_anchor._prev = &_anchor;
_anchor._next = &_anchor;
}
/** Check whether the list is empty. */
bool empty() const {
return (&_anchor == _anchor._next);
}
/** Return an iterator to the start of the list.
* This can be used, for example, to iterate from the first element
* of the list to the last element of the list.
*/
iterator begin() {
return iterator(_anchor._next);
}
/** Return a reverse iterator to the start of the list.
* This can be used, for example, to iterate from the last element
* of the list to the first element of the list.
*/
iterator reverse_begin() {
return iterator(_anchor._prev);
}
/** Return an iterator to the end of the list. */
iterator end() {
return iterator(&_anchor);
}
/** Return a const iterator to the start of the list.
* This can be used, for example, to iterate from the first element
* of the list to the last element of the list.
*/
const_iterator begin() const {
return const_iterator(_anchor._next);
}
/** Return a const reverse iterator to the start of the list.
* This can be used, for example, to iterate from the last element
* of the list to the first element of the list.
*/
const_iterator reverse_begin() const {
return const_iterator(_anchor._prev);
}
/** Return a const iterator to the end of the list. */
const_iterator end() const {
return const_iterator(const_cast<NodeBase *>(&_anchor));
}
protected:
/**
* Erase an element at @p pos.
*/
NodeBase erase(NodeBase *pos) {
NodeBase n = *pos;
Node *node = static_cast<Node *>(pos);
n._prev->_next = n._next;
n._next->_prev = n._prev;
delete node;
return n;
}
/**
* Insert an @p element before @p pos.
*/
void insert(NodeBase *pos, const t_T &element) {
ListInternal::NodeBase *newNode = new Node(element);
assert(newNode);
newNode->_next = pos;
newNode->_prev = pos->_prev;
newNode->_prev->_next = newNode;
newNode->_next->_prev = newNode;
}
};
/** @} */
} // End of namespace Common
#endif