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xo-interpreter2 stack: refactor: string clases -> xo-stringtable2/

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Roland Conybeare 2026-03-05 13:02:12 +11:00
commit ab61cddb6b
41 changed files with 550 additions and 111 deletions
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121
xo-expression2/src/expression2/DUniqueString.cpp
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@ -1,121 +0,0 @@
/** @file DUniqueString.cpp
*
* @author Roland Conybeare, Jan 2026
**/
#include "DUniqueString.hpp"
#include "DString.hpp"
#include <xo/arena/padding.hpp>
#include <xo/indentlog/scope.hpp>
#include <cstring>
namespace xo {
using xo::mm::padding;
using xo::facet::typeseq;
namespace scm {
int
DUniqueString::compare(const DUniqueString & lhs, const DUniqueString & rhs)
{
if (&lhs == &rhs)
return 0;
return DString::compare(*(lhs._text()), *(rhs._text()));
}
DString *
DUniqueString::_text() const noexcept
{
// location of paired DString is chosen
// by allocator (DArena, probably).
//
// In general allocator alignment more conservative
// than C++ alignment
//
// Remmebr also: although DUniqueString has zero members,
// C++ requires it to behave asif size at least 1 byte
// for iterator consistency
// (e.g. because c++ would support iterating over
// std::vector<EmptyStruct>)
//
size_t offset = padding::with_padding(sizeof(*this));
assert(offset > 0);
return (DString *)(((std::byte *)this) + offset);
}
bool
DUniqueString::pretty(const ppindentinfo & ppii) const
{
return _text()->pretty(ppii);
}
DUniqueString *
DUniqueString::from_view(obj<AAllocator> mm,
std::string_view sv)
{
scope log(XO_DEBUG(false));
/** fine point: choosing to allocate DUniqueString ahead of DString,
* so it comes first in bump allocator
**/
void * mem = mm.super_alloc(typeseq::id<DUniqueString>(),
sizeof(DUniqueString));
DUniqueString * result = new (mem) DUniqueString();
/** allocated in memory immediate following @p result.
* This optimization saves us one pointer (8 bytes) in DUniqueString
* itself, plus one allocation header (8 bytes) for 16 bytes total
**/
DString * text = DString::from_view_suballoc(mm, sv);
log && log(xtag("result", result), xtag("result.text", result->_text()), xtag("text", text));
assert(text);
assert(text == result->_text());
/** must finish super-allocation before next alloc **/
mm.sub_alloc(0, true);
return result;
}
size_t
DUniqueString::shallow_size() const noexcept
{
return sizeof(DUniqueString);
}
DUniqueString *
DUniqueString::shallow_copy(obj<AAllocator> mm) const noexcept
{
// well-posed, but not expected to be used.
assert(false);
DUniqueString * copy = (DUniqueString *)mm.alloc_copy((std::byte *)this);
if (copy) {
// Copy assignment not implemented in general
// *copy = *this;
// in this case *copy already has the same size as *this
assert(size() <= capacity());
strncpy(copy->_text()->data(),
this->_text()->chars(),
this->size());
}
return copy;
}
size_t
DUniqueString::forward_children(obj<ACollector>) noexcept
{
return shallow_size();
}
} /*namespace scm*/
} /*namespace xo*/
/* end DUniqueString.cpp */