xo-reader2/xo-object2/include/xo/object2/DArray.hpp

172 lines
5.9 KiB
C++

/** @file DArray.hpp
*
* @author Roland Conybeare, Jan 2026
**/
#pragma once
#include <xo/gc/GCObject.hpp>
#include <xo/gc/Collector.hpp>
#include <xo/alloc2/Allocator.hpp>
#include <xo/facet/obj.hpp>
#include <xo/indentlog/print/ppindentinfo.hpp>
#include <concepts>
#include <cstdint>
namespace xo {
namespace scm {
/** @class DArray
* @brief Polymorphic array implementation with gc hooks
*
* 1D Array implementation for Schematika
* Like DString, this implementation has max capacity
* fixed at construction time, but not part of type.
* Can reallocate to change
**/
class DArray {
public:
/** @defgroup darray-types type traits **/
///@{
/** type for array size **/
using size_type = std::uint32_t;
/** xo allocator facet **/
using AAllocator = xo::mm::AAllocator;
/** garbage collector facet **/
using ACollector = xo::mm::ACollector;
/** gc-aware object facet **/
using AGCObject = xo::mm::AGCObject;
/** pretty-printer state for APrintable **/
using ppindentinfo = xo::print::ppindentinfo;
///@}
/** @defgroup darray-ctors constructors **/
///@{
/** default ctor. zero capacity sentinel **/
DArray() = default;
/** not simply copyable because of flexible array.
* Need allocator. See @ref clone
**/
DArray(const DArray &) = delete;
/** create empty array with space for @p cap elements
* using memory from allocator @p mm.
* Nullptr if space exhausted
**/
static DArray * empty(obj<AAllocator> mm,
size_type cap);
/** create copy of @p src using memory from @p mm
* with capacity for @p new_cap elements
**/
static DArray * copy(obj<AAllocator> mm,
DArray * src,
size_type new_cap);
/** create array containing elements @p args, using memory from @p mm.
* Nullptr if space exhausted.
*
* Use:
* Darray * v = DArray::array(mm, e1, e2, e3);
**/
template <typename... Args>
requires (std::same_as<Args, obj<AGCObject>> && ...)
static DArray * array(obj<AAllocator> mm, Args... args);
///@}
/** @defgroup darray-access acecss methods **/
///@{
/** true iff array is empty **/
bool is_empty() const noexcept { return size_ == 0; }
/** only support finite arrays :-) **/
bool is_finite() const noexcept { return true; }
/** array capacity **/
size_type capacity() const noexcept { return capacity_; }
/** current array size (number of elements) **/
size_type size() const noexcept { return size_; }
/** return element @p index of this array (0-based) **/
obj<AGCObject> at(size_type index) const;
const obj<AGCObject> & operator[](size_type index) const noexcept { return elts_[index]; }
obj<AGCObject> & operator[](size_type index) noexcept { return elts_[index]; }
///@}
/** @defgroup darray-iterators iterators **/
///@{
///@}
/** @defgroup darray-assign assignment **/
///@{
/** append @p elt at the end of array.
* true on success, false otherwise
**/
bool push_back(obj<AGCObject> elt) noexcept;
///@}
/** @defgroup darray-general general methods **/
///@{
/** resize to @p new_size. @p new_size may not be larger than capacity
* Return true if resize was accomplished; false otherwise.
**/
bool resize(size_type new_size) noexcept;
///@}
/** @defgroup darray-conversion-operators conversion operators **/
///@{
///@}
/** @defgroup darray-sequence-methods **/
///@{
///@}
/** @defgroup darray-printable-methods **/
///@{
/** pretty-printing support **/
bool pretty(const ppindentinfo & ppii) const;
///@}
/** @defgroup darray-gcobject-methods **/
///@{
/** shallow memory consumption. Excludes child objects **/
AAllocator::size_type shallow_size() const noexcept;
/** return shallow copy of this array, using memory from @p mm **/
DArray * shallow_copy(obj<AAllocator> mm) const noexcept;
/** forward elements to @p gc to-space; replace originals with forarding pointers **/
AAllocator::size_type forward_children(obj<ACollector> gc) noexcept;
///@}
private:
/** @defgroup darray-instance-variables instance variables **/
///@{
/** extent of @ref elts_ array **/
size_type capacity_ = 0;
/** array size
* Invariant: size_ <= capacity_
**/
size_type size_ = 0;
/** array elements, using flexible array **/
obj<AGCObject> elts_[];
///@}
};
template <typename... Args>
requires (std::same_as<Args, obj<DArray::AGCObject>> && ...)
DArray *
DArray::array(obj<AAllocator> mm, Args... args)
{
DArray * result = empty(mm, sizeof...(args));
if (result) {
(result->push_back(args), ...);
}
return result;
}
} /*namespace scm*/
} /*namespace xo*/
/* end DArray.hpp */