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json/include/nlohmann/detail/view/edit.hpp
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Niels Lohmann 8ac510b8d3 json_view: exceptions name the path and the bytes of the value 
With JSON_DIAGNOSTICS and JSON_DIAGNOSTIC_POSITIONS, the exceptions of views
now carry the same context as those of basic_json: "(/path) " and
"(bytes a-b) " in front of the message, in basic_json's format (with
JSON_DIAGNOSTICS, no context for the root). Before, views threw without any
context, and since get<T>() reads the view directly, conversions had lost
even the relative path they used to get through materialize().

The throw helpers of detail/view/errors.hpp take an error_site (document
and node; empty without the two macros). Only on the error path, the path is
found by descending from the root (pruned by subtree extent before the first
edit, a full walk through edited sequences after), and the bytes as
materialize() sets them (position_source; a container's end by following the
chain of last elements and scanning to the closing brackets). from_json() for
views and the strict enum macro put the same context in front through
exception_prefix(). Iterators keep their container only under the two
macros, for key(). Without the macros, the accessors compile to the same
code as before.

Tests compare every value's exceptions with those of the parsed or
materialized basic_json value, including edited documents; the checks that
were disabled under the two macros run again.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-30 21:51:23 +01:00

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// __ _____ _____ _____
// __| | __| | | | JSON for Modern C++
// | | |__ | | | | | | version 3.12.0
// |_____|_____|_____|_|___| https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT
#pragma once
#include <array> // array
#include <cmath> // isinf, isnan
#include <cstddef> // size_t
#include <cstdint> // int64_t, uint8_t, uint32_t, uint64_t
#include <cstring> // memmove
#include <limits> // numeric_limits
#include <string> // string, to_string
#include <type_traits> // decay, enable_if, integral_constant, is_arithmetic, is_convertible, is_floating_point, is_same, is_signed
#include <utility> // forward
#include <vector> // vector
#include <nlohmann/json.hpp>
#include <nlohmann/detail/view/document_data.hpp>
#include <nlohmann/detail/view/edit_storage.hpp>
#include <nlohmann/detail/view/errors.hpp>
#include <nlohmann/detail/view/lookup.hpp>
#include <nlohmann/detail/view/macro_scope.hpp>
#include <nlohmann/detail/view/node.hpp>
#include <nlohmann/detail/view/scan.hpp>
#include <nlohmann/detail/view/view_mode.hpp>
NLOHMANN_JSON_NAMESPACE_BEGIN
namespace detail
{
namespace view
{
/// the index of the first true condition (the number of conditions if none is)
template<bool... Conditions>
struct first_true : std::integral_constant<int, 0> {};
template<bool... Conditions>
struct first_true<false, Conditions...> : std::integral_constant < int, 1 + first_true<Conditions...>::value > {};
/// Checks a string the way basic_json's serializer does when it writes it
/// (type_error.316 with the same message), so that an editable document
/// only holds valid UTF-8: the error is at the first byte that no
/// well-formed sequence can continue with (Unicode, Table 3-7).
NLOHMANN_VIEW_ALWAYS_INLINE void check_utf8_bytewise(const unsigned char* p, std::size_t n, std::size_t i)
{
while (i < n)
{
const unsigned char c = p[i];
if (c < 0x80)
{
++i;
continue;
}
const utf8_sequence_shape shape = utf8_shape(c);
const std::size_t len = shape.length;
if (len == 0)
{
throw_type_error(exception_id::invalid_utf8, concat("invalid UTF-8 byte at index ", std::to_string(i), ": 0x", hex_byte(c)));
}
for (std::size_t k = 1; k < len; ++k)
{
if (i + k == n)
{
throw_type_error(exception_id::invalid_utf8, concat("incomplete UTF-8 string; last byte: 0x", hex_byte(p[n - 1])));
}
const unsigned char b = p[i + k];
if (b < (k == 1 ? shape.second_lo : 0x80) || b > (k == 1 ? shape.second_hi : 0xBF))
{
throw_type_error(exception_id::invalid_utf8, concat("invalid UTF-8 byte at index ", std::to_string(i + k), ": 0x", hex_byte(b)));
}
}
i += len;
}
}
/// The long-string path of check_utf8(): skips well-formed runs with the
/// parser's string scan (which stops at a quote, a backslash, or a control
/// character, all legal here, and at ill-formed UTF-8); the byte-wise check
/// runs only from where the scan found ill-formed UTF-8, to report it.
NLOHMANN_VIEW_NOINLINE inline void check_utf8_scan(const unsigned char* p, std::size_t n)
{
const unsigned char* const e = p + n;
const unsigned char* q = p;
for (;;)
{
q = scan_string_run<true>(q, e);
if (q == e)
{
return;
}
if (*q >= 0x80)
{
check_utf8_bytewise(p, n, static_cast<std::size_t>(q - p));
return; // not reached: the scan stopped at ill-formed UTF-8
}
++q; // a quote, backslash, or control character
}
}
inline void check_utf8(const char* s, std::size_t n)
{
const auto* const p = reinterpret_cast<const unsigned char*>(s); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
if (NLOHMANN_VIEW_UNLIKELY(n >= 32))
{
check_utf8_scan(p, n);
return;
}
// short strings: the vector scan costs more than it saves; (the loop is
// inlined with a constant start, so this path is the plain byte-wise check)
check_utf8_bytewise(p, n, 0);
}
/*!
@brief the edits of an editable basic_json_document
Values are accepted as views (of any document), BasicJsonType values, and
everything BasicJsonType can be constructed from. The source text is never
written: new values go to storage owned by the document (see
edit_storage.hpp).
*/
template<typename BasicJsonType, typename View>
class editor
{
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
using string_view_t = typename View::string_view_t;
using nav = navigation<true>;
public:
explicit editor(document_data& d) noexcept
: m_doc(d)
{}
/// replace a value; returns its view
template<typename V>
View set(const View& target, V&& value)
{
node* const slot = own(target);
const encoded e = encode(std::forward<V>(value));
assign(slot, e, nullptr, false);
return View(&m_doc, slot);
}
/// set a member (appended if missing; a null value becomes an object);
/// returns a view of the member value
template<typename V>
View set(const View& object, string_view_t key, V&& value)
{
node* const o = own(object);
if (o->kind != node_kind::object && o->kind != node_kind::null)
{
throw_type_error(site_of(object), exception_id::subscript_wrong_type, "cannot use operator[] with a string argument with ", object.type_name());
}
check_utf8(key.data(), key.size());
const encoded e = encode(std::forward<V>(value));
if (o->kind == node_kind::null)
{
become_empty(o, node_kind::object);
}
// an existing member: assign it (and drop later duplicates, so that
// lookups, iteration, and materialize() agree)
node* slot = nullptr;
bool duplicates = false;
for (const node* k = nav::first(m_doc, o), *end = nav::end(m_doc, o); k != end; k = document_data::after(k + 1))
{
if (key_equals(*k, key))
{
if (slot != nullptr)
{
duplicates = true;
break;
}
slot = const_cast<node*>(nav::value(k + 1)); // NOLINT(cppcoreguidelines-pro-type-const-cast): the nodes belong to this document
}
}
if (slot != nullptr)
{
if (duplicates)
{
erase_members(o, key, true);
}
assign(slot, e, o, true);
return View(&m_doc, slot);
}
const node k = string_node(key.data(), key.size());
slot = new_slot(e);
node* const h = block_of(m_doc, o, 2);
h[h->next] = k;
make_link(h[h->next + 1], slot);
h->next += 2;
++h->len;
++o->len;
return View(&m_doc, slot);
}
/// assign an existing array element; returns a view of it
template<typename V>
View set(const View& array, std::size_t idx, V&& value)
{
node* const a = own(array);
if (a->kind != node_kind::array)
{
throw_type_error(site_of(array), exception_id::subscript_wrong_type, "cannot use operator[] with a numeric argument with ", array.type_name());
}
check_index(a, idx, a->len);
const encoded e = encode(std::forward<V>(value));
node* const slot = const_cast<node*>(nav::value(element_at<true>(m_doc, a, idx))); // NOLINT(cppcoreguidelines-pro-type-const-cast)
assign(slot, e, a, true);
return View(&m_doc, slot);
}
/// append to an array (a null value becomes an array); returns a view of
/// the new element
template<typename V>
View push_back(const View& array, V&& value)
{
node* const a = own(array);
if (a->kind != node_kind::array && a->kind != node_kind::null)
{
throw_type_error(site_of(array), exception_id::push_back_wrong_type, "cannot use push_back() with ", array.type_name());
}
const encoded e = encode(std::forward<V>(value));
if (a->kind == node_kind::null)
{
become_empty(a, node_kind::array);
}
node* const slot = new_slot(e);
node* const h = block_of(m_doc, a, 1);
make_link(h[h->next], slot);
++h->next;
++h->len;
++a->len;
return View(&m_doc, slot);
}
/// insert into an array before position idx (idx <= size()); returns a
/// view of the new element
template<typename V>
View insert(const View& array, std::size_t idx, V&& value)
{
node* const a = own(array);
if (a->kind != node_kind::array)
{
throw_type_error(site_of(array), exception_id::insert_wrong_type, "cannot use insert() with ", array.type_name());
}
check_index(a, idx, a->len + 1);
const encoded e = encode(std::forward<V>(value));
node* const slot = new_slot(e);
node* const h = block_of(m_doc, a, 1);
std::memmove(h + 2 + idx, h + 1 + idx, (h->next - 1 - idx) * sizeof(node));
make_link(h[1 + idx], slot);
++h->next;
++h->len;
++a->len;
return View(&m_doc, slot);
}
/// remove all members with this key; returns their number
std::size_t erase(const View& object, string_view_t key)
{
node* const o = own(object);
if (o->kind != node_kind::object)
{
throw_type_error(site_of(object), exception_id::erase_wrong_type, "cannot use erase() with ", object.type_name());
}
for (const node* k = nav::first(m_doc, o), *end = nav::end(m_doc, o); k != end; k = document_data::after(k + 1))
{
if (key_equals(*k, key))
{
return erase_members(o, key, false);
}
}
return 0;
}
/// remove an array element
void erase(const View& array, std::size_t idx)
{
node* const a = own(array);
if (a->kind != node_kind::array)
{
throw_type_error(site_of(array), exception_id::erase_wrong_type, "cannot use erase() with ", array.type_name());
}
check_index(a, idx, a->len);
node* const h = block_of(m_doc, a, 0);
std::memmove(h + 1 + idx, h + 2 + idx, (h->next - 2 - idx) * sizeof(node));
--h->next;
--h->len;
--a->len;
}
private:
/// an encoded value: a scalar node, or the root of a new array/object
struct encoded
{
node scalar{};
node* region = nullptr;
};
/// the node of a view of this document
node* own(const View& v)
{
if (NLOHMANN_VIEW_UNLIKELY(v.m_doc != &m_doc || v.m_node == nullptr))
{
throw_invalid_iterator(exception_id::iterator_from_other_value, "view does not belong to this document");
}
edit_state_of(m_doc);
return const_cast<node*>(v.m_node); // NOLINT(cppcoreguidelines-pro-type-const-cast): the nodes belong to this document
}
void check_index(const node* array, std::size_t idx, std::size_t limit) const
{
if (idx >= limit)
{
throw_array_index_out_of_range(error_site(&m_doc, array), idx);
}
}
bool key_equals(const node& k, string_view_t key) const noexcept
{
return m_doc.key_equals(k, key.data(), key.size());
}
/// remove the members with this key (all, or all but the first) from an object
std::size_t erase_members(node* o, string_view_t key, bool keep_first)
{
node* const h = block_of(m_doc, o, 0);
node* w = h + 1;
std::size_t erased = 0;
bool kept = false;
for (const node* r = h + 1, *end = h + h->next; r != end; r += 2)
{
const bool match = key_equals(*r, key);
if (match && (kept || !keep_first))
{
++erased;
continue;
}
kept = kept || match;
if (w != r)
{
w[0] = r[0];
w[1] = r[1];
}
w += 2;
}
h->next = static_cast<std::uint32_t>(w - h);
h->len -= static_cast<std::uint32_t>(erased);
o->len -= static_cast<std::uint32_t>(erased);
return erased;
}
/// turn a null into an empty array/object in place
static void become_empty(node* n, node_kind k) noexcept
{
const std::uint8_t linked = n->flags & node_flags::linked;
*n = node{};
n->kind = k;
n->flags = static_cast<std::uint8_t>(node_flags::is_new | linked);
n->next = 1;
}
/// Replace the value at slot; `parent` is the container whose elements
/// include slot (if known).
void assign(node* slot, const encoded& e, node* parent, bool parent_known)
{
// an entry of a moved sequence links to the slot: it can take any extent
const std::uint8_t linked = slot->flags & node_flags::linked;
if (e.region == nullptr)
{
if (is_container(*slot) && slot->next > 1 && slot != m_doc.nodes && linked == 0)
{
// The slot spans its old elements in the enclosing sequence, but
// a scalar is one node: the enclosing container first switches to
// links (then the extent of the slot no longer matters). Looking
// for the container is linear in the size of the document, so
// links (which are marked in the slot) avoid it.
node* const p = parent_known ? parent : find_parent(m_doc, slot);
if (p != nullptr && ((p->flags & node_flags::moved) == 0 || moved_capacity(m_doc, p) == 0))
{
block_of(m_doc, p, 0);
}
}
*slot = e.scalar;
slot->flags = static_cast<std::uint8_t>(slot->flags | linked);
return;
}
// an array/object: the slot keeps its extent (so that the enclosing
// sequence still steps over it), and the elements come from the new
// sequence
const node* const r = e.region;
const std::uint32_t extent = is_container(*slot) ? slot->next : 1;
const bool was_moved = (slot->flags & node_flags::moved) != 0;
// Everything that can throw happens before the slot changes: a slot
// that is a container without the moved flag would show its old
// elements. reserve_moved() makes the set_moved() below, which sets
// the flag, safe; the entry of `regions` exists already (encode()
// added it), so that the assignment at the end does not allocate.
if (!was_moved)
{
reserve_moved(m_doc);
}
slot->kind = r->kind;
slot->extra = 0;
slot->len = r->len;
slot->next = extent;
// (set_moved() adds the moved flag to a slot that does not have it yet)
slot->flags = static_cast<std::uint8_t>((was_moved ? node_flags::moved | node_flags::is_new : 0) | linked);
set_moved(m_doc, slot, e.region, 0);
edit_state_of(m_doc).regions[e.region] = slot;
}
/// a node for a new element (links point to it; it never moves)
node* new_slot(const encoded& e)
{
if (e.region != nullptr)
{
return e.region;
}
node* const s = alloc_nodes(m_doc, 1);
*s = e.scalar;
return s;
}
//////////////
// encoding //
//////////////
template<int N>
using encode_tag = std::integral_constant<int, N>;
template<typename T>
struct is_view : std::false_type {};
template<typename J, view_mode M>
struct is_view<basic_json_view<J, M>> : std::true_type {};
template<typename V>
encoded encode(V&& v)
{
using D = typename std::decay<V>::type;
return encode_impl(std::forward<V>(v), encode_tag<first_true<is_view<D>::value,
std::is_same<D, BasicJsonType>::value,
std::is_same<D, std::nullptr_t>::value,
std::is_same<D, bool>::value,
std::is_arithmetic<D>::value,
std::is_convertible<const D&, string_view_t>::value>::value> {});
}
/// a view of any document (copied; nothing is shared with it)
template<typename J, view_mode M>
encoded encode_impl(const basic_json_view<J, M>& v, encode_tag<0> /*view*/)
{
if (NLOHMANN_VIEW_UNLIKELY(v.m_node == nullptr))
{
throw_type_error(exception_id::type_mismatch, "type must be a value, but is ", "discarded");
}
encoded r;
if (!is_container(*v.m_node))
{
r.scalar = copy_scalar(*v.m_doc, *v.m_node);
return r;
}
r.region = alloc_nodes(m_doc, count_nodes<M == view_mode::editable>(*v.m_doc, v.m_node));
fill_nodes<M == view_mode::editable>(*v.m_doc, v.m_node, r.region);
edit_state_of(m_doc).regions.emplace(r.region, nullptr);
return r;
}
encoded encode_impl(const BasicJsonType& j, encode_tag<1> /*json*/)
{
encoded r;
if (!j.is_structured())
{
r.scalar = json_scalar(j);
return r;
}
r.region = alloc_nodes(m_doc, count_nodes(j));
fill_nodes(j, r.region);
edit_state_of(m_doc).regions.emplace(r.region, nullptr);
return r;
}
encoded encode_impl(std::nullptr_t /*unused*/, encode_tag<2> /*null*/)
{
encoded r;
r.scalar = plain_node(node_kind::null);
return r;
}
encoded encode_impl(bool b, encode_tag<3> /*boolean*/)
{
encoded r;
r.scalar = plain_node(node_kind::boolean);
r.scalar.flags = static_cast<std::uint8_t>(r.scalar.flags | (b ? node_flags::is_true : 0));
return r;
}
template<typename T>
encoded encode_impl(T x, encode_tag<4> /*number*/)
{
encoded r;
r.scalar = number_node(x, std::integral_constant<int, first_true<std::is_floating_point<T>::value, std::is_signed<T>::value>::value> {});
return r;
}
template<typename T>
encoded encode_impl(const T& s, encode_tag<5> /*string*/)
{
const string_view_t sv(s);
check_utf8(sv.data(), sv.size());
encoded r;
r.scalar = string_node(sv.data(), sv.size());
return r;
}
template<typename T>
encoded encode_impl(T&& x, encode_tag<6> /*other*/)
{
return encode_impl(BasicJsonType(std::forward<T>(x)), encode_tag<1> {});
}
static node plain_node(node_kind k) noexcept
{
node n{};
n.kind = k;
n.flags = node_flags::is_new;
return n;
}
template<typename T>
node number_node(T x, std::integral_constant<int, 0> /*floating-point*/)
{
return float_node(static_cast<number_float_t>(x));
}
template<typename T>
node number_node(T x, std::integral_constant<int, 1> /*signed*/)
{
return integer_node(static_cast<std::uint64_t>(static_cast<std::int64_t>(x)), node_kind::number_integer);
}
template<typename T>
node number_node(T x, std::integral_constant<int, 2> /*unsigned*/)
{
return integer_node(static_cast<std::uint64_t>(x), node_kind::number_unsigned);
}
/// an integer with its canonical token in the edit arena
node integer_node(std::uint64_t bits, node_kind k)
{
const bool negative = k == node_kind::number_integer && static_cast<std::int64_t>(bits) < 0;
std::uint64_t magnitude = negative ? 0 - bits : bits;
std::array<char, 24> buf{};
char* p = buf.data() + buf.size(); // NOLINT(misc-const-correctness): digits are written through p
do
{
*--p = static_cast<char>('0' + (magnitude % 10));
magnitude /= 10;
}
while (magnitude != 0);
if (negative)
{
*--p = '-';
}
const auto len = static_cast<std::size_t>(buf.data() + buf.size() - p);
node n = plain_node(k);
n.flags = static_cast<std::uint8_t>(n.flags | node_flags::edited);
n.off = append_text(m_doc, p, len);
// number_length() adds one for the sign of number_integer nodes
n.extra = static_cast<std::uint16_t>(k == node_kind::number_integer ? len - 1 : len);
set_integer_bits(n, bits);
return n;
}
/// a float with its shortest round-trip token (as basic_json::dump()
/// writes it), or nan, inf, -inf, in the edit arena
node float_node(number_float_t x)
{
string_t text;
if (std::isnan(x))
{
text = "nan";
}
else if (std::isinf(x))
{
text = x > 0 ? "inf" : "-inf";
}
else
{
text = BasicJsonType(x).dump();
}
node n = plain_node(node_kind::number_float);
n.flags = static_cast<std::uint8_t>(n.flags | node_flags::edited);
n.extra = 0xFFFFu; // (the digit layout is not recorded)
n.off = append_text(m_doc, text.data(), text.size());
n.len = static_cast<std::uint32_t>(text.size());
return n;
}
/// a string (or key) in the edit arena
node string_node(const char* s, std::size_t len)
{
if (NLOHMANN_VIEW_UNLIKELY(len >= 0xFFFFFFFFu))
{
throw_out_of_range(exception_id::document_too_large, "strings of 4 GiB or more are not supported by json_document"); // LCOV_EXCL_LINE
}
node n = plain_node(node_kind::string);
n.flags = static_cast<std::uint8_t>(n.flags | node_flags::edited);
n.off = append_text(m_doc, s, len);
n.len = static_cast<std::uint32_t>(len);
return n;
}
/// a scalar of a view (of any document) as a node of this document
node copy_scalar(const document_data& from, const node& n)
{
if (&from == &m_doc)
{
return n; // the same storage
}
switch (static_cast<value_t>(n.kind))
{
case value_t::string:
// (an editable document only holds valid UTF-8, whatever the check of the other document was)
check_utf8(from.str(n), n.len);
return string_node(from.str(n), n.len);
case value_t::number_integer:
case value_t::number_unsigned:
return integer_node(integer_bits(n), n.kind);
case value_t::number_float:
{
node r = plain_node(node_kind::number_float);
r.flags = static_cast<std::uint8_t>(r.flags | node_flags::edited);
r.off = append_text(m_doc, from.str(n), n.len);
r.len = n.len;
r.extra = n.extra;
return r;
}
case value_t::boolean:
{
node r = plain_node(node_kind::boolean);
r.flags = static_cast<std::uint8_t>(r.flags | (n.flags & node_flags::is_true));
return r;
}
case value_t::null:
case value_t::object:
case value_t::array:
case value_t::binary:
case value_t::discarded:
default:
return plain_node(node_kind::null);
}
}
node json_scalar(const BasicJsonType& j)
{
switch (j.type())
{
case value_t::null:
return plain_node(node_kind::null);
case value_t::boolean:
{
node r = plain_node(node_kind::boolean);
r.flags = static_cast<std::uint8_t>(r.flags | (j.template get<bool>() ? node_flags::is_true : 0));
return r;
}
case value_t::number_integer:
return integer_node(static_cast<std::uint64_t>(static_cast<std::int64_t>(j.template get<number_integer_t>())), node_kind::number_integer);
case value_t::number_unsigned:
return integer_node(static_cast<std::uint64_t>(j.template get<number_unsigned_t>()), node_kind::number_unsigned);
case value_t::number_float:
return float_node(j.template get<number_float_t>());
case value_t::string:
{
const auto& s = j.template get_ref<const string_t&>();
check_utf8(s.data(), s.size());
return string_node(s.data(), s.size());
}
case value_t::binary:
throw_type_error(exception_id::document_binary_value, "cannot store a binary value in a json_document", "");
case value_t::discarded:
case value_t::object:
case value_t::array:
default:
throw_type_error(exception_id::type_mismatch, "type must be a value, but is ", "discarded");
}
}
// The subtrees are walked with an explicit stack (as materialize() does):
// the nesting depth is limited by memory only, not by the call stack.
/// number of nodes of a subtree (containers, keys, scalars)
template<bool E>
static std::size_t count_nodes(const document_data& d, const node* n)
{
using walk = navigation<E>;
struct frame
{
const node* pos; ///< next element, or key of the next member
const node* end;
bool object;
};
std::vector<frame> open;
std::size_t r = 0;
for (;;)
{
++r;
if (is_container(*n))
{
open.push_back(frame{walk::first(d, n), walk::end(d, n), n->kind == node_kind::object});
}
// the next value: close finished containers, then step over the key
for (;;)
{
if (open.empty())
{
return r;
}
frame& f = open.back();
if (f.pos == f.end)
{
open.pop_back();
continue;
}
const node* v = f.pos;
if (f.object)
{
++r; // the key
++v;
}
f.pos = document_data::after(v);
n = walk::value(v);
break;
}
}
}
/// copy a subtree (of any document) as a contiguous sequence of
/// count_nodes() nodes
template<bool E>
void fill_nodes(const document_data& d, const node* n, node* out)
{
using walk = navigation<E>;
struct frame
{
const node* pos; ///< next element, or key of the next member
const node* end;
bool object;
node* self; ///< the container in the copy
};
std::vector<frame> open;
for (;;)
{
if (is_container(*n))
{
node* const self = out++;
*self = plain_node(n->kind);
self->len = n->len;
open.push_back(frame{walk::first(d, n), walk::end(d, n), n->kind == node_kind::object, self});
}
else
{
*out++ = copy_scalar(d, *n);
}
// the next value: close finished containers, then copy the key
for (;;)
{
if (open.empty())
{
return;
}
frame& f = open.back();
if (f.pos == f.end)
{
f.self->next = static_cast<std::uint32_t>(out - f.self);
open.pop_back();
continue;
}
const node* v = f.pos;
if (f.object)
{
*out++ = copy_scalar(d, *v);
++v;
}
f.pos = document_data::after(v);
n = walk::value(v);
break;
}
}
}
static std::size_t count_nodes(const BasicJsonType& j)
{
using iterator = typename BasicJsonType::const_iterator;
struct frame
{
iterator pos;
iterator end;
bool object;
};
std::vector<frame> open;
const BasicJsonType* n = &j;
std::size_t r = 0;
for (;;)
{
++r;
if (n->is_structured())
{
open.push_back(frame{n->cbegin(), n->cend(), n->is_object()});
}
for (;;)
{
if (open.empty())
{
return r;
}
frame& f = open.back();
if (f.pos == f.end)
{
open.pop_back();
continue;
}
r += f.object ? 1 : 0; // the key
n = &*f.pos;
++f.pos;
break;
}
}
}
void fill_nodes(const BasicJsonType& j, node* out)
{
using iterator = typename BasicJsonType::const_iterator;
struct frame
{
iterator pos;
iterator end;
bool object;
node* self; ///< the container in the copy
};
std::vector<frame> open;
const BasicJsonType* n = &j;
for (;;)
{
if (n->is_structured())
{
node* const self = out++;
*self = plain_node(static_cast<node_kind>(n->type()));
self->len = static_cast<std::uint32_t>(n->size());
open.push_back(frame{n->cbegin(), n->cend(), n->is_object(), self});
}
else
{
*out++ = json_scalar(*n);
}
for (;;)
{
if (open.empty())
{
return;
}
frame& f = open.back();
if (f.pos == f.end)
{
f.self->next = static_cast<std::uint32_t>(out - f.self);
open.pop_back();
continue;
}
if (f.object)
{
const auto& key = f.pos.key();
check_utf8(key.data(), key.size());
*out++ = string_node(key.data(), key.size());
}
n = &*f.pos;
++f.pos;
break;
}
}
}
document_data& m_doc;
};
} // namespace view
} // namespace detail
NLOHMANN_JSON_NAMESPACE_END
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