Rename names that Flawfinder takes for the file function open()

The comparison cursors' open() is now enter(), and a test's open and
close strings are head and tail.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/docs/api/basic_json_view/at.md

@@ -80,8 +80,7 @@ None of these exceptions carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics
    Objects with 128 or more members get a hash index of their keys while parsing, so that a lookup in them takes
    constant time on average.
 2. Linear in `idx`: elements are skipped one at a time from the first one, since they are not a fixed size in the
-   index (unlike `BasicJsonType`'s array, which is random-access). Constant if no element of the array is an array
+   index (unlike `BasicJsonType`'s array, which is random-access).
-   or object, since the elements are then adjacent in the index.
 3. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
    that level (as 1.) or the index into the array (as 2.).
 

docs/mkdocs/docs/api/basic_json_view/back.md

@@ -28,8 +28,7 @@ This exception does not carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.
 
 Linear in the size of the array or object: unlike [`front()`](front.md), which only ever looks at the first
 element, `back()` has to walk every element to find where they end, since elements are not a fixed size in the
-index. Constant for an array none of whose elements is an array or object, since the elements are then adjacent
+index.
-in the index.
 
 ## Notes
 

docs/mkdocs/docs/api/basic_json_view/operator[].md

@@ -86,8 +86,7 @@ None of these exceptions carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics
    Objects with 128 or more members get a hash index of their keys while parsing, so that a lookup in them takes
    constant time on average.
 2. Linear in `idx`: elements are skipped one at a time from the first one, since they are not a fixed size in the
-   index (unlike `BasicJsonType`'s array, which is random-access). Constant if no element of the array is an array
+   index (unlike `BasicJsonType`'s array, which is random-access).
-   or object, since the elements are then adjacent in the index.
 3. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
    that level (as 1.) or the index into the array (as 2.).
 

include/nlohmann/detail/view/builder.hpp

@@ -275,41 +275,11 @@ class builder
                 0, 0, '\b', 0, 0, 0, '\f', 0, 0, 0, 0, 0, 0, 0, '\n', 0, 0, 0, '\r', 0, '\t', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
             }
         };
-        // The write position is kept in locals: the stores of characters into
-        // the arena may alias the members of the builder, which would then be
-        // reloaded after every one. It is stored back where the arena grows
-        // and at the end.
-        const unsigned char* const end = m_end;
         const std::size_t start = arena_used();
-        char* w = m_arena_write;
+        arena_run(s, static_cast<std::size_t>(p - s));
-        const char* w_end = m_arena_end;
-#define NLOHMANN_VIEW_ENSURE(n)                                                       \
-    if (NLOHMANN_VIEW_UNLIKELY(static_cast<std::size_t>(w_end - w) < (n)))            \
-    {                                                                                 \
-        m_arena_write = w;                                                            \
-        arena_grow(n);                                                                \
-        w = m_arena_write;                                                            \
-        w_end = m_arena_end;                                                          \
-    }
-        {
-            const auto n = static_cast<std::size_t>(p - s);
-            if (n <= 16 && end - s >= 16)
-            {
-                NLOHMANN_VIEW_ENSURE(16)
-                std::memcpy(w, s, 16);
-            }
-            else if (n != 0)
-            {
-                // (an empty run leaves an empty arena unallocated, and memcpy()
-                // must not be passed its null pointer even for zero bytes)
-                NLOHMANN_VIEW_ENSURE(n)
-                std::memcpy(w, s, n);
-            }
-            w += n;
-        }
         for (;;)
         {
-            if (p == end)
+            if (p == m_end)
             {
                 return failed(error_code::string_missing_quote, p);
             }
@@ -317,7 +287,6 @@ class builder
             if (c == '"')
             {
                 ++p;
-                m_arena_write = w;
                 return decoded{p, start, arena_used() - start};
             }
             if (c != '\\')
@@ -328,7 +297,7 @@ class builder
                 return failed(c < 0x20 ? error_code::string_control_character : error_code::string_utf8, p);
             }
             ++p;
-            if (p == end)
+            if (p == m_end)
             {
                 return failed(error_code::string_missing_quote, p);
             }
@@ -346,7 +315,7 @@ class builder
                     {
                         return failed(error_code::string_surrogate_low, p);
                     }
-                    if (end - p < 2 || p[0] != '\\' || p[1] != 'u')
+                    if (m_end - p < 2 || p[0] != '\\' || p[1] != 'u')
                     {
                         return failed(error_code::string_surrogate_high, p);
                     }
@@ -362,108 +331,27 @@ class builder
                     }
                     cp = 0x10000 + ((cp - 0xD800) << 10) + (lo - 0xDC00);
                 }
-                NLOHMANN_VIEW_ENSURE(4)
+                arena_ensure(4);
-                w = put_utf8(w, cp);
+                m_arena_write = put_utf8(m_arena_write, cp);
             }
             else if (NLOHMANN_VIEW_LIKELY(d < 128 && simple_escape[d] != 0))
             {
-                NLOHMANN_VIEW_ENSURE(1)
+                arena_ensure(1);
-                *w++ = simple_escape[d];
+                *m_arena_write++ = simple_escape[d];
             }
             else
             {
                 --p;
                 return failed(error_code::string_escape, p);
             }
-#if NLOHMANN_VIEW_NEON
+            if (p != m_end && *p == '\\')
-            if (p != end && *p == '\\')
             {
                 continue; // consecutive escapes ("\u00e4\u00f6"): no run in between
             }
-            // The first 16 bytes of the run are checked one by one, in predicted branches, and copied
-            // as one block: where the runs between escapes are short, the vector step below would put
-            // its longer dependency chain (load, compare, mask, count, add) on p for each of them,
-            // and be slower than these steps (the scanner of the keys works the same way)
-            {
-                if (end - p >= 16)
-                {
-                    const std::uint8_t* const plain = string_plain();
-                    std::size_t steps = 16;
-#define NLOHMANN_VIEW_STEP(i) if (NLOHMANN_VIEW_LIKELY(plain[p[i]] != 0)) {} else { steps = (i); goto run_found; }
-                    NLOHMANN_VIEW_REPEAT16(NLOHMANN_VIEW_STEP)
-#undef NLOHMANN_VIEW_STEP
-run_found:
-                    NLOHMANN_VIEW_ENSURE(16)
-                    std::memcpy(w, p, 16); // (only the first `steps` bytes are kept)
-                    w += steps;
-                    p += steps;
-                    if (steps < 16)
-                    {
-                        if (*p >= 0x80)
-                        {
-                            // non-ASCII: the UTF-8 check, and the rest of the run
             const unsigned char* const r = p;
-                            p = scan_string_run(p, end);
+            p = scan_string_run(p, m_end);
-                            const auto n = static_cast<std::size_t>(p - r);
+            arena_run(r, static_cast<std::size_t>(p - r));
-                            NLOHMANN_VIEW_ENSURE(n)
-                            std::memcpy(w, r, n);
-                            w += n;
         }
-                        continue;
-                    }
-                }
-            }
-#else
-            if (p != end && (*p == '\\' || *p == '"'))
-            {
-                continue; // consecutive escapes ("\u00e4\u00f6"), or the end of the string: no run in between
-            }
-#endif
-#if NLOHMANN_VIEW_VECTOR
-            // the plain bytes up to the next quote, backslash, or control
-            // character are copied as they are scanned, 16 bytes at a time
-            for (;;)
-            {
-                if (NLOHMANN_VIEW_UNLIKELY(end - p < 16))
-                {
-                    const unsigned char* const r = p;
-                    p = scan_string_run(p, end);
-                    const auto n = static_cast<std::size_t>(p - r);
-                    NLOHMANN_VIEW_ENSURE(n)
-                    std::memcpy(w, r, n);
-                    w += n;
-                    break;
-                }
-                NLOHMANN_VIEW_ENSURE(16)
-                const unsigned k = copy_plain_run16(p, w);
-                w += k;
-                p += k;
-                if (k == 16)
-                {
-                    continue;
-                }
-                if (NLOHMANN_VIEW_UNLIKELY(*p >= 0x80))
-                {
-                    // non-ASCII: the UTF-8 check, and the rest of the run
-                    const unsigned char* const r = p;
-                    p = scan_string_run(p, end);
-                    const auto n = static_cast<std::size_t>(p - r);
-                    NLOHMANN_VIEW_ENSURE(n)
-                    std::memcpy(w, r, n);
-                    w += n;
-                }
-                break;
-            }
-#else
-            const unsigned char* const r = p;
-            p = scan_string_run(p, end);
-            const auto n = static_cast<std::size_t>(p - r);
-            NLOHMANN_VIEW_ENSURE(n)
-            std::memcpy(w, r, n);
-            w += n;
-#endif
-        }
-#undef NLOHMANN_VIEW_ENSURE
     }
 
     /// does the float token [s, p) overflow FloatType? (parse() rejects it)
@@ -509,6 +397,14 @@ run_found:
         return m_arena_write != nullptr ? static_cast<std::size_t>(m_arena_write - m_doc.arena.data()) : 0;
     }
 
+    NLOHMANN_VIEW_ALWAYS_INLINE void arena_ensure(std::size_t n)
+    {
+        if (NLOHMANN_VIEW_UNLIKELY(static_cast<std::size_t>(m_arena_end - m_arena_write) < n))
+        {
+            arena_grow(n);
+        }
+    }
+
     NLOHMANN_VIEW_NOINLINE void arena_grow(std::size_t n)
     {
         const std::size_t used = arena_used();
@@ -517,6 +413,25 @@ run_found:
         m_arena_end = m_doc.arena.data() + m_doc.arena.size();
     }
 
+    /// append the run [r, r + n) to the arena; short runs as one fixed-size
+    /// 16-byte move when both sides have the room (no library call)
+    NLOHMANN_VIEW_ALWAYS_INLINE void arena_run(const unsigned char* r, std::size_t n)
+    {
+        if (n <= 16 && m_end - r >= 16)
+        {
+            arena_ensure(16);
+            std::memcpy(m_arena_write, r, 16);
+        }
+        else if (n != 0)
+        {
+            // (an empty run leaves an empty arena unallocated, and memcpy()
+            // must not be passed its null pointer even for zero bytes)
+            arena_ensure(n);
+            std::memcpy(m_arena_write, r, n);
+        }
+        m_arena_write += n;
+    }
+
     /// UTF-8 encoding of cp at w (room for 4 bytes); returns the position after
     /// it. (A returned pointer stays in a register; writing through a
     /// reference to m_arena_write would store and reload it around every byte.)
@@ -1039,11 +954,11 @@ indent_done:
                 ++p;
             }
             const unsigned char* const int_start = p;
-            if (cur() == '0')
+            if (p != e && *p == '0')
             {
                 ++p;
             }
-            else if (NLOHMANN_VIEW_LIKELY(cur() >= '1' && cur() <= '9'))
+            else if (NLOHMANN_VIEW_LIKELY(p != e && *p >= '1' && *p <= '9'))
             {
                 p = skip_digits(p + 1, e);
             }
@@ -1054,7 +969,7 @@ indent_done:
             const auto int_digits = static_cast<std::size_t>(p - int_start);
             std::size_t frac_digits = 0;
             bool is_float = false;
-            if (cur() == '.')
+            if (p != e && *p == '.')
             {
                 ++p;
                 const unsigned char* const f0 = p;
@@ -1067,20 +982,20 @@ indent_done:
                 is_float = true;
             }
             std::int64_t exponent = 0;
-            if ((cur() | 0x20) == 'e')
+            if (p != e && (*p | 0x20) == 'e')
             {
                 ++p;
                 bool exp_negative = false;
-                if (cur() == '+' || cur() == '-')
+                if (p != e && (*p == '+' || *p == '-'))
                 {
                     exp_negative = *p == '-';
                     ++p;
                 }
-                if (NLOHMANN_VIEW_UNLIKELY(!is_digit(cur())))
+                if (NLOHMANN_VIEW_UNLIKELY(p == e || !is_digit(*p)))
                 {
                     return fail(error_code::number_after_exponent);
                 }
-                while (is_digit(cur()))
+                while (p != e && is_digit(*p))
                 {
                     if (exponent < 100000)
                     {
@@ -1142,7 +1057,7 @@ indent_done:
             ++p; // opening quote
             const unsigned char* const s = p;
             p = scan_string_run<Value>(p, e);
-            if (NLOHMANN_VIEW_LIKELY(cur() == '"'))
+            if (NLOHMANN_VIEW_LIKELY(p != e && *p == '"'))
             {
                 push_node(value_t::string, 0, 0, static_cast<std::size_t>(s - b), static_cast<std::uint64_t>(p - s));
                 ++p;

include/nlohmann/detail/view/image.hpp

@@ -255,6 +255,82 @@ struct number_token
     bool is_float; ///< a fraction or an exponent
 };
 
+/// advance over ASCII digits, eight bytes at a time
+inline const unsigned char* digit_run(const unsigned char* p, const unsigned char* e) noexcept
+{
+    constexpr std::uint64_t ones = 0x0101010101010101ull;
+    while (e - p >= 8)
+    {
+        // (the digits become 0..9; a byte above 9, or with bit 7 set, is no digit. A carry
+        // out of a byte with bit 7 set only affects the bytes above, after the first one
+        // that count_trailing_zeros finds.)
+        const std::uint64_t x = read_eight_bytes(p) ^ (ones * 0x30u);
+        const std::uint64_t not_digit = ((x + (ones * 0x76u)) | x) & (ones * 0x80u);
+        if (not_digit != 0)
+        {
+            return p + (static_cast<std::size_t>(count_trailing_zeros(not_digit)) / 8);
+        }
+        p += 8;
+    }
+    while (p != e && is_digit(*p))
+    {
+        ++p;
+    }
+    return p;
+}
+
+/// whether the n bytes at p are ASCII digits (n > 0)
+inline bool all_digits(const unsigned char* p, std::size_t n) noexcept
+{
+    constexpr std::uint64_t ones = 0x0101010101010101ull;
+    const auto digits = [](const unsigned char* q)
+    {
+        const std::uint64_t x = read_eight_bytes(q) ^ (ones * 0x30u);
+        return (((x + (ones * 0x76u)) | x) & (ones * 0x80u)) == 0;
+    };
+    if (n >= 8)
+    {
+        std::size_t i = 0;
+        for (; i + 8 < n; i += 8)
+        {
+            if (!digits(p + i))
+            {
+                return false;
+            }
+        }
+        return digits(p + n - 8); // (overlapping the bytes before: they are digits)
+    }
+    for (std::size_t i = 0; i < n; ++i)
+    {
+        if (!is_digit(p[i]))
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+/// Whether a float token has the shape that the parser records for most of
+/// them: [-]digits.digits, with the numbers of digits of the node's layout
+/// (extra). Then the token is a number of that layout, and the general scan
+/// that follows is not needed.
+inline bool plain_float_token(const unsigned char* s, std::size_t len, std::uint16_t extra) noexcept
+{
+    const std::size_t int_digits = extra & 0xFFu;
+    const std::size_t frac_digits = extra >> 8u;
+    if (int_digits == 0 || int_digits >= 255 || frac_digits == 0 || frac_digits >= 255 || len == 0)
+    {
+        return false;
+    }
+    const std::size_t negative = *s == '-' ? 1 : 0;
+    if (len != negative + int_digits + 1 + frac_digits)
+    {
+        return false;
+    }
+    const unsigned char* const p = s + negative;
+    return !(int_digits > 1 && *p == '0') && p[int_digits] == '.' && all_digits(p, int_digits) && all_digits(p + int_digits + 1, frac_digits);
+}
+
 /// whether [s, s + len) is a JSON number (the grammar the parser accepts)
 inline bool scan_number_token(const unsigned char* s, std::size_t len, number_token& t)
 {
@@ -273,11 +349,7 @@ inline bool scan_number_token(const unsigned char* s, std::size_t len, number_to
     }
     else if (*p >= '1' && *p <= '9')
     {
-        do
+        p = digit_run(p + 1, e);
-        {
-            ++p;
-        }
-        while (p != e && is_digit(*p));
     }
     else
     {
@@ -289,10 +361,7 @@ inline bool scan_number_token(const unsigned char* s, std::size_t len, number_to
     if (p != e && *p == '.')
     {
         const unsigned char* const f0 = ++p;
-        while (p != e && is_digit(*p))
+        p = digit_run(p, e);
-        {
-            ++p;
-        }
         if (p == f0)
         {
             return false;
@@ -403,10 +472,15 @@ struct float_range
 template<typename Check>
 bool check_distinct_ranges(std::vector<byte_range>& ranges, Check check)
 {
-    std::sort(ranges.begin(), ranges.end(), [](const byte_range & a, const byte_range & b)
+    // (save() writes the ranges in the order of the nodes, which is sorted already)
+    const auto before = [](const byte_range & a, const byte_range & b)
     {
         return a.off != b.off ? a.off < b.off : a.len < b.len;
-    });
+    };
+    if (!std::is_sorted(ranges.begin(), ranges.end(), before))
+    {
+        std::sort(ranges.begin(), ranges.end(), before);
+    }
     std::size_t end = 0;
     for (std::size_t i = 0; i < ranges.size(); ++i)
     {
@@ -428,7 +502,8 @@ bool check_distinct_ranges(std::vector<byte_range>& ranges, Check check)
 /// record layouts that match it), tokens must not overlap.
 inline bool check_float_ranges(std::vector<float_range>& ranges, const unsigned char* text)
 {
-    std::sort(ranges.begin(), ranges.end(), [](const float_range & a, const float_range & b)
+    // (save() writes the tokens in the order of the nodes, which is sorted already)
+    const auto before = [](const float_range & a, const float_range & b)
     {
         if (a.off != b.off)
         {
@@ -439,7 +514,11 @@ inline bool check_float_ranges(std::vector<float_range>& ranges, const unsigned
             return a.len < b.len;
         }
         return a.extra < b.extra;
-    });
+    };
+    if (!std::is_sorted(ranges.begin(), ranges.end(), before))
+    {
+        std::sort(ranges.begin(), ranges.end(), before);
+    }
     std::size_t end = 0;
     std::size_t i = 0;
     while (i < ranges.size())
@@ -449,14 +528,18 @@ inline bool check_float_ranges(std::vector<float_range>& ranges, const unsigned
         {
             return false;
         }
-        number_token t{};
         const unsigned char* const s = text + r.off;
+        std::uint16_t layout = r.extra;
+        if (!plain_float_token(s, r.len, r.extra))
+        {
+            number_token t{};
             if (!scan_number_token(s, r.len, t) || !float_token_finite(s, r.len, t))
             {
                 return false;
             }
             // the digit layout the parser records (or "many", as compaction writes it)
-        const std::uint16_t layout = float_layout(t);
+            layout = float_layout(t);
+        }
         for (; i < ranges.size() && ranges[i].off == r.off && ranges[i].len == r.len; ++i)
         {
             if (ranges[i].extra != layout && ranges[i].extra != 0xFFFFu)

include/nlohmann/detail/view/input.hpp

@@ -10,9 +10,6 @@
 
 #include <algorithm> // max
 #include <cstddef> // size_t
-#ifndef JSON_NO_IO
-    #include <cstdio> // FILE, fread
-#endif
 #include <istream> // istream, streambuf
 #include <string> // basic_string, char_traits, string
 #include <type_traits> // decay, integral_constant, is_array, is_const, is_integral, is_lvalue_reference, is_pointer, is_same, remove_cv, remove_extent, remove_pointer, remove_reference
@@ -157,37 +154,6 @@ inline void append_stream(std::string& buf, std::istream& is)
     is.clear(is.rdstate() | std::ios::eofbit);
 }
 
-/// a pointer to a C stream (never with JSON_NO_IO, which leaves out <cstdio>)
-template<typename T>
-struct is_c_stream
-#ifndef JSON_NO_IO
-    : std::is_same<T, std::FILE*>
-#else
-    : std::false_type
-#endif
-{};
-
-#ifndef JSON_NO_IO
-/// append the rest of a C stream: in blocks with fread, not character by
-/// character (the library's file adapter reads with fgetc);
-/// f is not null
-inline void append_file(std::string& buf, std::FILE* f)
-{
-    for (;;)
-    {
-        const std::size_t used = buf.size();
-        const std::size_t room = (std::max)(buf.capacity() - used, std::size_t{4096});
-        buf.resize(used + room);
-        const std::size_t got = std::fread(&buf[used], 1, room, f);
-        buf.resize(used + got);
-        if (got < room)
-        {
-            break; // end of file, or an error (as fgetc, which returns EOF for both)
-        }
-    }
-}
-#endif
-
 }  // namespace view
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/detail/view/iterator.hpp

@@ -147,21 +147,20 @@ class view_item
 
     view_item(const iterator& it, std::size_t index)
         : m_it(it)
-        , m_position(index)
+    {
-    {}
+        if (!it.is_object_iterator())
+        {
+            m_index = std::to_string(index);
+        }
+    }
 
-    /// the member key, or the element index for arrays (as text made on the
+    /// the member key, or the element index for arrays
-    /// first call, so that iterating over the values pays nothing for it)
     string_view_t key() const
     {
         if (m_it.is_object_iterator())
         {
             return m_it.key();
         }
-        if (m_index.empty())
-        {
-            m_index = std::to_string(m_position);
-        }
         return string_view_t(m_index.data(), m_index.size());
     }
 
@@ -184,8 +183,7 @@ class view_item
 
   private:
     iterator m_it;
-    std::size_t m_position; ///< the index of an array element
+    std::string m_index{}; // NOLINT(readability-redundant-member-init)
-    mutable std::string m_index{}; ///< the text of m_position, once key() was called // NOLINT(readability-redundant-member-init)
 };
 
 /// the range returned by basic_json_view::items()

include/nlohmann/detail/view/lookup.hpp

@@ -166,10 +166,6 @@ const node* element_at(const document_data& d, const node* array, std::size_t id
     {
         return e + idx; // a growable block: one link per element
     }
-    if (array->next == array->len + 1u && (!nav::editable() || (array->flags & node_flags::moved) == 0))
-    {
-        return e + idx; // no element has a subtree: the elements are the nodes after the array
-    }
     for (std::size_t i = 0; i < idx; ++i)
     {
         e = document_data::after(e);
@@ -185,10 +181,6 @@ const node* last_child(const document_data& d, const node* container) noexcept
     const std::size_t value_offset = container->kind == static_cast<std::uint8_t>(value_t::object) ? 1 : 0;
     const node* const end = navigation<Editable>::end(d, container);
     const node* last = navigation<Editable>::first(d, container);
-    if (value_offset == 0 && container->next == container->len + 1u && (!navigation<Editable>::editable() || (container->flags & node_flags::moved) == 0))
-    {
-        return last + (container->len - 1u); // an array without subtrees: the elements are the nodes after it
-    }
     for (const node* c = document_data::after(last + value_offset); c != end; c = document_data::after(c + value_offset))
     {
         last = c;

include/nlohmann/detail/view/materialize.hpp

@@ -8,7 +8,7 @@
 
 #pragma once
 
-#include <array> // array
+#include <algorithm> // max
 #include <cstddef> // size_t
 #include <cstdint> // int64_t, uint8_t
 #include <string> // string
@@ -44,9 +44,8 @@ BasicJsonType materialize(const document_data& d, const node* n)
     using nav = navigation<Editable>;
 
     // the open containers: their next element (or key of the next member),
-    // their end, and whether they are objects; for the first 16 levels on the
+    // their end, and whether they are objects; sized once from the
-    // stack, else sized once from the document's deepest nesting (for a
+    // document's deepest nesting (for a subtree an upper bound)
-    // subtree an upper bound)
     struct frame
     {
         const node* pos;
@@ -54,43 +53,10 @@ BasicJsonType materialize(const document_data& d, const node* n)
         bool object;
     };
 
-    // a scalar needs neither the handler nor the stack of open containers
-    switch (static_cast<value_t>(n->kind))
-    {
-        case value_t::string:
-            return BasicJsonType(string_t(d.str(*n), n->len));
-        case value_t::number_integer:
-            return BasicJsonType(static_cast<typename BasicJsonType::number_integer_t>(static_cast<std::int64_t>(integer_bits(*n))));
-        case value_t::number_unsigned:
-            return BasicJsonType(static_cast<typename BasicJsonType::number_unsigned_t>(integer_bits(*n)));
-        case value_t::number_float:
-            return BasicJsonType(float_value<typename BasicJsonType::number_float_t>(d, *n));
-        case value_t::boolean:
-            return BasicJsonType((n->flags & node_flags::is_true) != 0);
-        case value_t::null:
-            return BasicJsonType(nullptr);
-        case value_t::object:
-        case value_t::array:
-        case value_t::binary:
-        case value_t::discarded:
-        default:
-            break;
-    }
-
     BasicJsonType result;
     sax_t sax(result, true);
     const string_t no_token{};
-    // (shallow subtrees on the stack: a call for a small value then allocates only for the value)
+    std::vector<frame> open((std::max)(d.max_depth, std::size_t{1}));
-    std::array<frame, 16> shallow; // NOLINT(cppcoreguidelines-pro-type-member-init,hicpp-member-init): filled as containers open
-    std::vector<frame> deep{};
-    frame* open = shallow.data();
-    std::size_t capacity = shallow.size();
-    if (d.max_depth > capacity)
-    {
-        deep.resize(d.max_depth);
-        open = deep.data();
-        capacity = deep.size();
-    }
     std::size_t depth = 0;
     for (;;)
     {
@@ -110,13 +76,9 @@ BasicJsonType materialize(const document_data& d, const node* n)
                 {
                     sax.start_array(n->len);
                 }
-                if (NLOHMANN_VIEW_UNLIKELY(depth == capacity))
+                if (NLOHMANN_VIEW_UNLIKELY(depth == open.size()))
                 {
-                    // (deeper than the recorded nesting, e.g. after edits)
+                    open.resize(depth * 2); // (deeper than the recorded nesting, e.g. after edits)
-                    deep.assign(open, open + depth);
-                    deep.resize(depth * 2);
-                    open = deep.data();
-                    capacity = deep.size();
                 }
                 open[depth++] = frame{nav::first(d, n), nav::end(d, n), object};
                 break;

include/nlohmann/detail/view/node.hpp

@@ -120,6 +120,74 @@ NLOHMANN_VIEW_ALWAYS_INLINE std::uint32_t number_length(const node& n) noexcept
            : (n.extra & 0xFFu) + (n.kind == static_cast<std::uint8_t>(value_t::number_integer) ? 1u : 0u);
 }
 
+/// whether n bytes are equal; the short texts of JSON (keys, numbers, most
+/// strings) are compared by two overlapping loads instead of a library call
+NLOHMANN_VIEW_ALWAYS_INLINE bool bytes_equal(const char* x, const char* y, std::size_t n) noexcept
+{
+    const auto load8 = [](const char* p)
+    {
+        std::uint64_t v = 0;
+        std::memcpy(&v, p, sizeof(v));
+        return v;
+    };
+    const auto load4 = [](const char* p)
+    {
+        std::uint32_t v = 0;
+        std::memcpy(&v, p, sizeof(v));
+        return v;
+    };
+    if (n >= 8)
+    {
+        std::size_t i = 0;
+        for (; i + 8 < n; i += 8)
+        {
+            if (load8(x + i) != load8(y + i))
+            {
+                return false;
+            }
+        }
+        return load8(x + n - 8) == load8(y + n - 8);
+    }
+    if (n >= 4)
+    {
+        return load4(x) == load4(y) && load4(x + n - 4) == load4(y + n - 4);
+    }
+    for (std::size_t i = 0; i < n; ++i)
+    {
+        if (x[i] != y[i])
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+/// whether the n1 bytes at x are before the n2 bytes at y (memcmp() order, then the shorter first);
+/// the first difference is found eight bytes at a time
+NLOHMANN_VIEW_ALWAYS_INLINE bool bytes_less(const char* x, std::size_t n1, const char* y, std::size_t n2) noexcept
+{
+    const std::size_t n = n1 < n2 ? n1 : n2;
+    std::size_t i = 0;
+    for (; i + 8 <= n; i += 8)
+    {
+        const std::uint64_t u = read_eight_bytes(x + i);
+        const std::uint64_t v = read_eight_bytes(y + i);
+        if (u != v)
+        {
+            const auto shift = static_cast<unsigned>(count_trailing_zeros(u ^ v)) & ~7u; // (the first byte that differs)
+            return ((u >> shift) & 0xFFu) < ((v >> shift) & 0xFFu);
+        }
+    }
+    for (; i < n; ++i)
+    {
+        if (x[i] != y[i])
+        {
+            return static_cast<unsigned char>(x[i]) < static_cast<unsigned char>(y[i]);
+        }
+    }
+    return n1 < n2;
+}
+
 /// estimated number of nodes for an input of `size` bytes (one node per ~12
 /// bytes covers typical documents without regrowth)
 inline std::size_t estimate_nodes(std::size_t size) noexcept

include/nlohmann/detail/view/object_index.hpp

@@ -47,96 +47,27 @@ constexpr std::size_t index_max_displacement = 64;
 static_assert(document_data::index_min_members >= 2 * index_max_displacement,
               "a table must be much larger than the probe window of a lookup");
 
-/// hash of a key: its bytes, eight at a time (in a fixed byte order), where the
+/// hash of a key: its bytes, eight at a time, in a fixed byte order
-/// last word may overlap the one before (so that no loop over single bytes is
-/// needed); a key of fewer than eight bytes is read as two overlapping words of
-/// four or two bytes (in the native byte order: the hash is not stored, and the
-/// same on both sides of a lookup)
 inline std::uint64_t key_hash(const char* s, std::size_t n) noexcept
 {
     std::uint64_t h = 0x9E3779B97F4A7C15u * (n + 1);
     const auto* p = reinterpret_cast<const unsigned char*>(s); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
-    std::uint64_t w = 0;
+    while (n >= 8)
-    if (n >= 8)
-    {
-        const unsigned char* const last = p + n - 8;
-        while (p < last)
     {
         h = (h ^ read_eight_bytes(p)) * 0xBF58476D1CE4E5B9u;
         h ^= h >> 29u;
         p += 8;
+        n -= 8;
     }
-        w = read_eight_bytes(last);
+    std::uint64_t w = 0;
-    }
+    for (std::size_t i = 0; i < n; ++i)
-    else if (n >= 4)
     {
-        std::uint32_t head = 0;
+        w |= static_cast<std::uint64_t>(p[i]) << (8u * i);
-        std::uint32_t tail = 0;
-        std::memcpy(&head, p, 4);
-        std::memcpy(&tail, p + n - 4, 4);
-        w = static_cast<std::uint64_t>(head) | (static_cast<std::uint64_t>(tail) << 32u);
     }
-    else if (n >= 2)
+    h = (h ^ w) * 0x94D049BB133111EBu;
-    {
-        std::uint16_t head = 0;
-        std::uint16_t tail = 0;
-        std::memcpy(&head, p, 2);
-        std::memcpy(&tail, p + n - 2, 2);
-        w = static_cast<std::uint64_t>(head) | (static_cast<std::uint64_t>(tail) << 16u);
-    }
-    else if (n == 1)
-    {
-        w = p[0];
-    }
-    // (a product only carries bits upwards, and the slot is taken from the low
-    // bits: the high bits of the last word are folded down before the multiplication)
-    h = (h ^ w ^ (w >> 29u)) * 0x94D049BB133111EBu;
     return h ^ (h >> 31u);
 }
 
-/// whether the n <= 16 bytes at a and b are equal, as two overlapping words
-/// (the first and the last 8, 4, or 2 bytes) and without a call
-NLOHMANN_VIEW_ALWAYS_INLINE bool same_short_bytes(const unsigned char* a, const unsigned char* b, std::size_t n) noexcept
-{
-    if (n >= 8)
-    {
-        std::uint64_t x0 = 0;
-        std::uint64_t x1 = 0;
-        std::uint64_t y0 = 0;
-        std::uint64_t y1 = 0;
-        std::memcpy(&x0, a, 8);
-        std::memcpy(&x1, a + n - 8, 8);
-        std::memcpy(&y0, b, 8);
-        std::memcpy(&y1, b + n - 8, 8);
-        return x0 == y0 && x1 == y1;
-    }
-    if (n >= 4)
-    {
-        std::uint32_t x0 = 0;
-        std::uint32_t x1 = 0;
-        std::uint32_t y0 = 0;
-        std::uint32_t y1 = 0;
-        std::memcpy(&x0, a, 4);
-        std::memcpy(&x1, a + n - 4, 4);
-        std::memcpy(&y0, b, 4);
-        std::memcpy(&y1, b + n - 4, 4);
-        return x0 == y0 && x1 == y1;
-    }
-    if (n >= 2)
-    {
-        std::uint16_t x0 = 0;
-        std::uint16_t x1 = 0;
-        std::uint16_t y0 = 0;
-        std::uint16_t y1 = 0;
-        std::memcpy(&x0, a, 2);
-        std::memcpy(&x1, a + n - 2, 2);
-        std::memcpy(&y0, b, 2);
-        std::memcpy(&y1, b + n - 2, 2);
-        return x0 == y0 && x1 == y1;
-    }
-    return n == 0 || *a == *b;
-}
-
 /// build the table of a large object
 inline void build_object_index(document_data& d, node* obj)
 {
@@ -201,27 +132,6 @@ inline const node* find_indexed(const document_data& d, const node* obj, const c
     const document_data::object_index& ix = d.indexes[obj->extra - 1u];
     const std::uint32_t* const table = d.index_slots.data() + ix.start;
     std::size_t slot = conditional_static_cast<std::size_t>(key_hash(key, n)) & ix.mask;
-    const auto* const k_bytes = reinterpret_cast<const unsigned char*>(key); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
-    // (the loop for longer keys comes first, as the code is laid out; it is not the more common case)
-    if (NLOHMANN_VIEW_UNLIKELY(n <= 16))
-    {
-        // (up to 16 bytes, the bytes are compared as two words, without a call)
-        for (std::size_t distance = 0; distance <= index_max_displacement; ++distance)
-        {
-            const std::uint32_t s = table[slot];
-            if (s == 0)
-            {
-                return nullptr;
-            }
-            const node* const k = obj + s;
-            if (k->len == n && same_short_bytes(reinterpret_cast<const unsigned char*>(d.str(*k)), k_bytes, n)) // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
-            {
-                return k;
-            }
-            slot = (slot + 1) & ix.mask;
-        }
-        return nullptr;
-    }
     for (std::size_t distance = 0; distance <= index_max_displacement; ++distance)
     {
         const std::uint32_t s = table[slot];

include/nlohmann/detail/view/simd.hpp

@@ -116,34 +116,6 @@ NLOHMANN_VIEW_ALWAYS_INLINE const unsigned char* vector_plain_run(const unsigned
     }
     return p;
 }
-
-/*!
-@brief copy 16 bytes from p to w, and find the first quote, backslash,
-control character, or non-ASCII byte among them
-
-The bytes are copied whether or not they are all plain (the caller has room
-for 16 bytes and keeps only the plain ones).
-
-@return the offset of that byte, or 16 if there is none
-*/
-NLOHMANN_VIEW_ALWAYS_INLINE unsigned copy_plain_run16(const unsigned char* p, char* w) noexcept
-{
-#if NLOHMANN_VIEW_NEON
-    const uint8x16_t in = vld1q_u8(p);
-    vst1q_u8(reinterpret_cast<std::uint8_t*>(w), in); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
-    const uint8x16_t special = vorrq_u8(vorrq_u8(vceqq_u8(in, vdupq_n_u8('"')), vceqq_u8(in, vdupq_n_u8('\\'))),
-                                        vcltq_s8(vreinterpretq_s8_u8(in), vdupq_n_s8(0x20)));
-    const std::uint64_t bits = vget_lane_u64(vreinterpret_u64_u8(vshrn_n_u16(vreinterpretq_u16_u8(special), 4)), 0);
-    return bits != 0 ? static_cast<unsigned>(count_trailing_zeros(bits) >> 2u) : 16u;
-#else
-    const __m128i in = _mm_loadu_si128(static_cast<const __m128i*>(static_cast<const void*>(p))); // NOLINT(bugprone-casting-through-void)
-    _mm_storeu_si128(static_cast<__m128i*>(static_cast<void*>(w)), in); // NOLINT(bugprone-casting-through-void)
-    const __m128i special = _mm_or_si128(_mm_or_si128(_mm_cmpeq_epi8(in, _mm_set1_epi8('"')), _mm_cmpeq_epi8(in, _mm_set1_epi8('\\'))),
-                                         _mm_cmplt_epi8(in, _mm_set1_epi8(0x20)));
-    const auto bits = static_cast<std::uint64_t>(static_cast<unsigned>(_mm_movemask_epi8(special)));
-    return bits != 0 ? static_cast<unsigned>(count_trailing_zeros(bits)) : 16u;
-#endif
-}
 #endif
 
 #if NLOHMANN_VIEW_SSSE3_DISPATCH

include/nlohmann/json_view.hpp

@@ -295,7 +295,7 @@ class basic_json_view
             }
             detail::view::throw_type_error(305, "cannot use operator[] with a numeric argument with ", type_name());
         }
-        return idx < m_node->len ? element(idx) : basic_json_view();
+        return idx < m_node->len ? basic_json_view(m_doc, navigation::value(detail::view::element_at<Editable>(*m_doc, m_node, idx))) : basic_json_view();
     }
 
     /// any other integer type (int, unsigned, long, std::int64_t, ...; a
@@ -358,7 +358,7 @@ class basic_json_view
         {
             detail::view::throw_out_of_range(401, detail::concat("array index ", std::to_string(idx), " is out of range"));
         }
-        return element(idx);
+        return basic_json_view(m_doc, navigation::value(detail::view::element_at<Editable>(*m_doc, m_node, idx)));
     }
 
     /// any other integer type, see operator[]; negative values are out of
@@ -392,13 +392,7 @@ class basic_json_view
 
     string_t value(string_view_t key, const char* default_value) const
     {
-        if (NLOHMANN_VIEW_UNLIKELY(!is_object()))
+        return value(key, string_t(default_value));
-        {
-            detail::view::throw_type_error(306, "cannot use value() with ", type_name());
-        }
-        // (the default is made only if there is no such member)
-        const basic_json_view r = lookup(key);
-        return r.is_discarded() ? string_t(default_value) : r.template get<string_t>();
     }
 
     /// the value a JSON pointer refers to converted to T, or the default
@@ -417,12 +411,7 @@ class basic_json_view
 
     string_t value(const json_pointer& ptr, const char* default_value) const
     {
-        if (NLOHMANN_VIEW_UNLIKELY(!is_structured()))
+        return value(ptr, string_t(default_value));
-        {
-            detail::view::throw_type_error(306, "cannot use value() with ", type_name());
-        }
-        const basic_json_view r = detail::view::resolve_pointer(*this, detail::json_pointer_access::reference_tokens(ptr), detail::view::pointer_mode::value);
-        return r.is_discarded() ? string_t(default_value) : r.template get<string_t>();
     }
 
     /// the first element or member value; a primitive value itself. Throws
@@ -444,8 +433,7 @@ class basic_json_view
     {
         if (is_structured() && m_node->len != 0)
         {
-            return unedited() ? basic_json_view(m_doc, detail::view::last_child<false>(*m_doc, m_node) + (is_object() ? 1 : 0))
+            return basic_json_view(m_doc, navigation::value(detail::view::last_child<Editable>(*m_doc, m_node) + (is_object() ? 1 : 0)));
-                   : basic_json_view(m_doc, navigation::value(detail::view::last_child<Editable>(*m_doc, m_node) + (is_object() ? 1 : 0)));
         }
         return front();
     }
@@ -462,8 +450,7 @@ class basic_json_view
         {
             return end();
         }
-        const node* const k = unedited() ? detail::view::find_member<false>(*m_doc, m_node, key.data(), key.size())
+        const node* const k = detail::view::find_member<Editable>(*m_doc, m_node, key.data(), key.size());
-                              : detail::view::find_member<Editable>(*m_doc, m_node, key.data(), key.size());
         return k != nullptr ? iterator(m_doc, k, true) : end();
     }
 
@@ -480,8 +467,7 @@ class basic_json_view
     /// whether this is an object with a member with this key
     bool contains(string_view_t key) const
     {
-        return is_object() && (unedited() ? detail::view::find_member<false>(*m_doc, m_node, key.data(), key.size()) != nullptr
+        return is_object() && detail::view::find_member<Editable>(*m_doc, m_node, key.data(), key.size()) != nullptr;
-                               : detail::view::find_member<Editable>(*m_doc, m_node, key.data(), key.size()) != nullptr);
     }
 
     bool contains(const char* key) const
@@ -641,14 +627,7 @@ class basic_json_view
         // the compact writer keeps 64 bytes of slack, so that it does not grow
         // the buffer just before the end
         const std::size_t estimate = source_extent() + (style.pretty ? source_extent() / 2 : 0) + 160;
-        if (unedited())
-        {
-            detail::view::view_serializer<BasicJsonType, false>(*m_doc, out, estimate, style).dump(m_node);
-        }
-        else
-        {
         detail::view::view_serializer<BasicJsonType, Editable>(*m_doc, out, estimate, style).dump(m_node);
-        }
         return out;
     }
 
@@ -728,7 +707,7 @@ class basic_json_view
         {
             return BasicJsonType(value_t::discarded);
         }
-        return unedited() ? detail::view::materialize<BasicJsonType, false>(*m_doc, m_node) : detail::view::materialize<BasicJsonType, Editable>(*m_doc, m_node);
+        return detail::view::materialize<BasicJsonType, Editable>(*m_doc, m_node);
     }
 
     /// byte offset of this value in the source text (for strings: of the
@@ -744,8 +723,12 @@ class basic_json_view
     template<typename, bool> friend class basic_json_document;
     template<typename, bool> friend class basic_json_view;
     template<typename, typename> friend class detail::view::editor;
+    template<typename, typename> friend class detail::view::view_side;
     friend iterator;
 
+    /// whether the view is one of an editable document
+    static constexpr bool is_editable = Editable;
+
     basic_json_view(const document_data* d, const node* n) noexcept
         : m_doc(d), m_node(n)
     {}
@@ -806,32 +789,10 @@ class basic_json_view
     /// (object required)
     NLOHMANN_VIEW_ALWAYS_INLINE basic_json_view lookup(string_view_t key) const noexcept
     {
-        if (unedited())
-        {
-            const node* const k = detail::view::find_member<false>(*m_doc, m_node, key.data(), key.size());
-            return k != nullptr ? basic_json_view(m_doc, k + 1) : basic_json_view();
-        }
         const node* const k = detail::view::find_member<Editable>(*m_doc, m_node, key.data(), key.size());
         return k != nullptr ? basic_json_view(m_doc, navigation::value(k + 1)) : basic_json_view();
     }
 
-    /// whether the document has not been edited yet: until the first edit, its index is walked like that of a
-    /// read-only document (nothing is moved or linked), which is cheaper
-    NLOHMANN_VIEW_ALWAYS_INLINE bool unedited() const noexcept
-    {
-        return !navigation::editable() || m_doc->edits == nullptr;
-    }
-
-    /// the element of an array at an index below its size
-    NLOHMANN_VIEW_ALWAYS_INLINE basic_json_view element(size_type idx) const
-    {
-        if (unedited())
-        {
-            return basic_json_view(m_doc, detail::view::element_at<false>(*m_doc, m_node, idx));
-        }
-        return basic_json_view(m_doc, navigation::value(detail::view::element_at<Editable>(*m_doc, m_node, idx)));
-    }
-
     // --- get() dispatch ---
 
     bool get_impl(detail::view::value_tag<bool> /*unused*/, detail::priority_tag<2> /*unused*/) const
@@ -1571,8 +1532,7 @@ class basic_json_document
         // NOLINTBEGIN(readability-avoid-nested-conditional-operator): a constant expression of C++11
         append_input_impl(buf, std::forward<T>(input), std::integral_constant < int, detail::is_contiguous_byte_container<D>::value ? 0
                           : std::is_base_of<std::istream, D>::value ? 1
-                          : detail::view::is_adapter_input<D>::value ? 2
+                          : detail::view::is_adapter_input<D>::value ? 2 : 3 > {});
-                          : detail::view::is_c_stream<D>::value ? 4 : 3 > {});
         // NOLINTEND(readability-avoid-nested-conditional-operator)
     }
 
@@ -1594,19 +1554,6 @@ class basic_json_document
         detail::view::append_adapter(buf, std::move(input.ia));
     }
 
-#ifndef JSON_NO_IO
-    static void append_input_impl(std::string& buf, std::FILE* file, std::integral_constant<int, 4> /*C stream*/)
-    {
-        if (file == nullptr)
-        {
-            // (as before: the library's adapter decides what a null stream yields)
-            detail::view::append_adapter(buf, detail::input_adapter(file));
-            return;
-        }
-        detail::view::append_file(buf, file);
-    }
-#endif
-
     template<typename T>
     static void append_input_impl(std::string& buf, T&& input, std::integral_constant<int, 3> /*other*/)
     {

tests/src/unit-json_view.cpp

@@ -185,29 +185,6 @@ TEST_CASE("json_view")
         // duplicate keys: the last value, at the position of the first key
         CHECK(materialized<json_document>(R"({"a":1,"b":2,"a":3})") == json::parse(R"({"a":1,"b":2,"a":3})"));
         CHECK(materialized<ordered_json_document>(R"({"a":1,"b":2,"a":3})").dump() == R"({"a":3,"b":2})");
-        // scalars (made without the handler), and nesting around the depth up to which the stack of open containers is local
-        for (const char* scalar :
-                {"null", "true", "false", "0", "-7", "18446744073709551615", "1.5e300", "-0.0", "\"\"", "\"short\"", "\"a string that is longer than fifteen bytes\"", "\"\\u00e4\\n\""
-                })
-        {
-            CAPTURE(scalar)
-            CHECK(materialized<json_document>(scalar) == json::parse(scalar));
-            const std::string in_array = std::string("[1,") + scalar + "]";
-            const json_document d = json_document::parse(in_array);
-            CHECK(d.root()[1].materialize() == json::parse(scalar));
-            CHECK(d.root()[1].get<json>() == json::parse(scalar));
-        }
-        for (const std::size_t levels :
-                {
-                    std::size_t{1}, std::size_t{15}, std::size_t{16}, std::size_t{17}, std::size_t{32}, std::size_t{33}
-                })
-        {
-            CAPTURE(levels)
-            const std::string nested = std::string(levels, '[') + "{\"k\":[1,{\"j\":2}]}" + std::string(levels, ']');
-            CHECK(materialized<json_document>(nested) == json::parse(nested));
-            const std::string wide = "{\"a\":" + nested + ",\"b\":" + nested + "}";
-            CHECK(materialized<json_document>(wide) == json::parse(wide));
-        }
         // very deep nesting (iterative, as parse())
         const std::string deep = std::string(100000, '[') + std::string(100000, ']');
         // (one check per step, so that a failure shows which step it is)
@@ -433,31 +410,6 @@ TEST_CASE("json_view")
         std::istringstream rvalue_source("[1]");
         CHECK(json_document::parse_copy(std::move(rvalue_source)).owns_source());
 
-        // a C stream is read in blocks as well (more than one block, and a
-        // text whose length is a multiple of the block size)
-        for (const std::size_t extra :
-                {
-                    std::size_t{0}, std::size_t{1}
-                })
-        {
-            std::FILE* long_file = std::tmpfile(); // NOLINT(cppcoreguidelines-owning-memory)
-            if (long_file != nullptr)
-            {
-                std::string padded = text;
-                padded.append((4096 - (padded.size() % 4096)) % 4096 + extra, ' ');
-                CHECK(std::fwrite(padded.data(), 1, padded.size(), long_file) == padded.size());
-                CHECK(std::fseek(long_file, 0, SEEK_SET) == 0);
-                const json_document from_long_file = json_document::parse(long_file);
-                CHECK(from_long_file.source() == padded);
-                CHECK(from_long_file.root().materialize() == json::parse(text));
-                CHECK(std::fclose(long_file) == 0); // NOLINT(cppcoreguidelines-owning-memory)
-            }
-        }
-        {
-            json_document from_null;
-            CHECK_THROWS_AS(from_null = json_document::parse(static_cast<std::FILE*>(nullptr)), json::parse_error&);
-        }
-
         // a stream without a buffer is an empty input
         std::istream no_buffer(nullptr);
         CHECK(json_document::parse(no_buffer, false).is_discarded());
@@ -1054,49 +1006,6 @@ TEST_CASE("json_view element access and iteration")
 #endif
     }
 
-    SECTION("arrays whose elements have no subtrees: index and back()")
-    {
-        // (the elements are adjacent in the index; an array, an object, or an
-        // empty container anywhere makes the lookup skip element by element)
-        const std::vector<std::string> texts =
-        {
-            "[]", "[1]", "[1,2,3]", "[1,\"two\",3.5,true,null,-7,18446744073709551615]", "[[]]", "[{}]", "[1,[2],3]",
-            "[1,2,{\"a\":3}]", "[[1,2],3,4]", "[1,2,3,[4,5,6,7,8],9,10,11,12]", "[{\"a\":[1]},2]", "[\"a\\u00e4\",\"b\"]"
-        };
-        for (const std::string& text : texts)
-        {
-            CAPTURE(text)
-            const json_document d = json_document::parse(text);
-            const json_view v = d.root();
-            const json expected = json::parse(text);
-            for (std::size_t i = 0; i < expected.size(); ++i)
-            {
-                CHECK(v[i].materialize() == expected[i]);
-                CHECK(v.at(i).materialize() == expected[i]);
-            }
-            CHECK(v[expected.size()].is_discarded());
-            if (!expected.empty())
-            {
-                CHECK(v.back().materialize() == expected.back());
-            }
-        }
-        // a long array (the direct lookup is not limited to short ones), also with a container at its end
-        std::string text = "[0";
-        for (int i = 1; i < 1000; ++i)
-        {
-            text += "," + std::to_string(i);
-        }
-        const json_document scalars = json_document::parse(text + "]");
-        CHECK(scalars.root()[999].get<int>() == 999);
-        CHECK(scalars.root()[500].get<int>() == 500);
-        CHECK(scalars.root().at(1).get<int>() == 1);
-        CHECK(scalars.root().back().get<int>() == 999);
-        const json_document container_last = json_document::parse(text + ",[1000]]");
-        CHECK(container_last.root()[999].get<int>() == 999);
-        CHECK(container_last.root()[1000][0].get<int>() == 1000);
-        CHECK(container_last.root().back()[0].get<int>() == 1000);
-    }
-
     SECTION("iterators")
     {
         const json_document d = json_document::parse(R"({"x":[1,{"y":2}],"z":null})");
@@ -1136,28 +1045,6 @@ TEST_CASE("json_view element access and iteration")
         CHECK((*first++).key() == "0");
         CHECK((*first).key() == "1");
         CHECK(++first == items.end());
-
-        // the keys of array elements are their indexes, whether or not they are asked for
-        std::string numbers = "[0";
-        for (int i = 1; i < 1234; ++i)
-        {
-            numbers += "," + std::to_string(i);
-        }
-        const json_document array = json_document::parse(numbers + "]");
-        std::size_t position = 0;
-        for (const auto& item : array.root().items())
-        {
-            CHECK(item.value().get<std::size_t>() == position);
-            if (position % 3 != 0) // (not for every item: values alone do not make the key)
-            {
-                CHECK(item.key() == std::to_string(position));
-                CHECK(item.key().data() == item.key().data()); // (the same text every time)
-                const json_view::item copy = item;
-                CHECK(copy.key() == std::to_string(position));
-            }
-            ++position;
-        }
-        CHECK(position == 1234);
 #ifdef JSON_HAS_CPP_17
         std::string pairs;
         for (const auto [key, value] : d.root().items())
@@ -1496,17 +1383,7 @@ TEST_CASE("json_view values")
         CHECK(exception_of([&] { static_cast<void>(v.value("s", 0)); }) == without_path(exception_of([&] { static_cast<void>(j.value("s", 0)); })));
         CHECK(exception_of([&] { static_cast<void>(v["n"].value("x", 0)); }) == without_path(exception_of([&] { static_cast<void>(j["n"].value("x", 0)); })));
         CHECK(exception_of([&] { static_cast<void>(v["n"].value(json::json_pointer("/x"), 0)); }) == without_path(exception_of([&] { static_cast<void>(j["n"].value(json::json_pointer("/x"), 0)); })));
-        // string defaults: the member is not a string, or the value is neither an object nor an array
-        CHECK(exception_of([&] { static_cast<void>(v.value("n", "default")); }) == without_path(exception_of([&] { static_cast<void>(j.value("n", "default")); })));
-        CHECK(exception_of([&] { static_cast<void>(v["n"].value("x", "default")); }) == without_path(exception_of([&] { static_cast<void>(j["n"].value("x", "default")); })));
-        CHECK(exception_of([&] { static_cast<void>(v.value(json::json_pointer("/n"), "default")); }) == without_path(exception_of([&] { static_cast<void>(j.value(json::json_pointer("/n"), "default")); })));
-        CHECK(exception_of([&] { static_cast<void>(v["s"].value(json::json_pointer("/x"), "default")); }) == without_path(exception_of([&] { static_cast<void>(j["s"].value(json::json_pointer("/x"), "default")); })));
 #endif
-        // (defaults and members longer than the short string optimization)
-        CHECK(v.value("s", "a default longer than fifteen characters") == "text");
-        CHECK(v.value("missing", "a default longer than fifteen characters") == "a default longer than fifteen characters");
-        CHECK(v.value(json::json_pointer("/s"), "a default longer than fifteen characters") == "text");
-        CHECK(v.value(json::json_pointer("/zz"), "a default longer than fifteen characters") == "a default longer than fifteen characters");
     }
 }
 

tests/src/unit-json_view_builder.cpp

@@ -523,58 +523,6 @@ TEST_CASE("json_view builder: strings across vector blocks")
     }
 }
 
-TEST_CASE("json_view builder: escapes between runs of text")
-{
-    // The text between escapes is copied 16 bytes at a time where there are
-    // that many bytes left, and with the UTF-8 check where there is
-    // non-ASCII text. Runs of every length from 0 to 40 between valid and
-    // invalid escapes, UTF-8 sequences, and control characters, in strings
-    // that are cut at all places near the end of the text.
-    const std::array<const char*, 9> valid = {{"\\n", "\\\"", "\\\\", "\\/", "\\t", "\\u00e4", "\\u20ac", "\\ud83d\\ude00", "\\u0000"}};
-    const std::array<const char*, 9> invalid = {{"\\x", "\\ud800", "\\udc00", "\\u12G4", "\\u12", "\\ud83dx", "\\ud83d\\u0041", "\\", "\x01"}};
-    const std::array<const char*, 6> utf8 = {{"\xc3\xa4", "\xe2\x82\xac", "\xf0\x9f\x98\x80", "\xc3", "\xff", "\x80"}};
-    std::mt19937 rng(2026); // NOLINT(cert-msc32-c,cert-msc51-cpp,bugprone-random-generator-seed): reproducible
-    for (std::size_t run = 0; run <= 40; ++run)
-    {
-        for (int i = 0; i < 60; ++i)
-        {
-            std::string content = std::string(rng() % 20, 'a');
-            const auto pieces = 1 + (rng() % 6);
-            for (unsigned k = 0; k < pieces; ++k)
-            {
-                content += valid[rng() % valid.size()];
-                content += std::string(k == 0 ? run : rng() % 41, static_cast<char>('b' + (rng() % 20)));
-                switch (rng() % 8)
-                {
-                    case 0:
-                        content += utf8[rng() % 3];
-                        break;
-                    case 1:
-                        content += utf8[rng() % utf8.size()];
-                        break;
-                    case 2:
-                        content += invalid[rng() % invalid.size()];
-                        break;
-                    default:
-                        break;
-                }
-            }
-            check_string(content);
-            check_string(content.substr(0, content.size() - (rng() % 4)));
-        }
-    }
-    // the text before the first escape, and runs and escapes at the end of the text
-    for (std::size_t before = 0; before <= 40; ++before)
-    {
-        for (const char* escape : valid)
-        {
-            check_string(std::string(before, 'a') + escape);
-            check_string(std::string(before, 'a') + escape + std::string(before % 19, 'z'));
-            check_string(std::string(before, 'a') + escape + escape + std::string(before % 19, 'z'));
-        }
-    }
-}
-
 TEST_CASE("json_view node integer bits")
 {
     using nlohmann::detail::view::integer_bits;

tests/src/unit-json_view_dump.cpp

@@ -21,7 +21,6 @@ using nlohmann::ordered_json_view;
 using json_view_test::generator;
 using json_view_test::has_duplicate_keys;
 
-#include <algorithm>
 #include <array>
 #include <cmath>
 #include <cstddef>
@@ -30,7 +29,6 @@ using json_view_test::has_duplicate_keys;
 #include <iomanip>
 #include <map>
 #include <random>
-#include <set>
 #include <sstream>
 #include <string>
 #include <vector>
@@ -347,6 +345,33 @@ TEST_CASE("json_view comparison")
         }
     }
 
+    SECTION("objects whose first keys differ or repeat")
+    {
+        const char* const texts[] =
+        {
+            R"({"a":1,"b":2})", R"({"a":1,"c":2})", R"({"b":1,"a":2})", R"({"a":1,"a":2,"b":3})", R"({"a":2,"b":3})",
+            R"({"a":1,"b":1,"a":2})", R"({"a":2,"b":1})", R"({"a":1,"a":2})", R"({"b":1})", R"({"a":1,"b":2,"c":3,"d":4,"e":5})",
+            R"({"a":1,"b":2,"c":3,"d":4,"f":5})", R"({"a":1,"b":2,"c":3,"a":4,"e":5})", R"({"a":4,"b":2,"c":3,"e":5})",
+            R"({"\u0061":1,"b":2})", R"({})", R"([{"a":1,"b":2}])", R"([{"a":1,"c":2}])"
+        };
+        for (const char* const x : texts)
+        {
+            for (const char* const y : texts)
+            {
+                CAPTURE(x)
+                CAPTURE(y)
+                const ordered_json_document dx = ordered_json_document::parse(x);
+                const ordered_json_document dy = ordered_json_document::parse(y);
+                const ordered_json_editable_document ex = ordered_json_editable_document::parse(x);
+                const ordered_json jx = ordered_json::parse(x);
+                const ordered_json jy = ordered_json::parse(y);
+                CHECK((dx.root() == dy.root()) == (jx == jy));
+                CHECK((dx.root() == jy) == (jx == jy));
+                CHECK((ex.root() == dy.root()) == (jx == jy));
+            }
+        }
+    }
+
     SECTION("numbers, duplicate keys, member order")
     {
         const auto same = [](const char* x, const char* y)
@@ -387,6 +412,129 @@ TEST_CASE("json_view comparison")
         CHECK(!(null_document.root() == discarded));
     }
 
+    SECTION("values that are the same text, or the same value written differently, at any depth")
+    {
+        // nested arrays and objects around depths where the walk over equal text gives up
+        for (const int depth :
+                {
+                    1, 5, 47, 48, 49, 50, 60, 300
+                })
+        {
+            CAPTURE(depth)
+            std::string head;
+            std::string tail;
+            for (int i = 0; i < depth; ++i)
+            {
+                head += i % 2 == 0 ? R"({"k":[1,"s",{"x":true},)" : R"([null,2.5,{"y":)";
+                tail = (i % 2 == 0 ? "]}" : "}]") + tail;
+            }
+            // the same text, one number changed, and one number written differently
+            const std::string text = head + "7" + tail;
+            const std::string changed = head + "8" + tail;
+            const std::string spelled = head + "7.0" + tail;
+            const json_document a = json_document::parse(text);
+            const json_document b = json_document::parse(text);
+            const json_document c = json_document::parse(changed);
+            const json_document d = json_document::parse(spelled);
+            CHECK(a.root() == b.root());
+            CHECK(a.root() != c.root());
+            CHECK(c.root() != a.root());
+            CHECK(a.root() == d.root());
+            CHECK(d.root() == a.root());
+            CHECK(a.root() == json::parse(text));
+            CHECK(a.root() != json::parse(changed));
+            CHECK(json::parse(spelled) == a.root());
+            const nlohmann::json_editable_document e = nlohmann::json_editable_document::parse(text);
+            CHECK(a.root() == e.root());
+            CHECK(e.root() == a.root());
+            CHECK(c.root() != e.root());
+            CHECK(e.root() == e.root());
+            const ordered_json_document oa = ordered_json_document::parse(text);
+            const ordered_json_document oc = ordered_json_document::parse(changed);
+            CHECK(oa.root() != oc.root());
+            CHECK(oa.root() == ordered_json::parse(text));
+            CHECK(oc.root() != ordered_json::parse(text));
+        }
+
+        // not the same text, but the same value
+        const auto same = [](const char* x, const char* y)
+        {
+            const json_document dx = json_document::parse(x);
+            const json_document dy = json_document::parse(y);
+            const bool equal = dx.root() == dy.root();
+            CHECK(equal == (json::parse(x) == json::parse(y)));
+            CHECK(equal == (dx.root() == json::parse(y)));
+            return equal;
+        };
+        CHECK(same(R"({"a":1,"a":2})", R"({"a":3,"a":2})"));
+        CHECK(same(R"({"a":1,"b":[1,{"c":2,"c":3}]})", R"({"b":[1,{"c":9,"c":3}],"a":1})"));
+        CHECK(!same(R"({"a":1,"a":2})", R"({"a":2,"a":3})"));
+        CHECK(same("[1.0,-0,0,1e2]", "[1.00,0,-0,100.0]"));
+        CHECK(same(R"(["\u00e9","\n"])", "[\"\xc3\xa9\",\"\\n\"]"));
+        CHECK(!same(R"({"a":[1,2,{"b":null}]})", R"({"a":[1,2,{"b":false}]})"));
+        CHECK(!same(R"({"a":[1,2,{"b":null}]})", R"({"a":[1,2,{"c":null}]})"));
+        CHECK(!same(R"({"a":[1,2,{"b":null}]})", R"({"a":[1,2,{"b":null,"c":1}]})"));
+
+        // edited documents: moved sequences, links, and values of new nodes
+        nlohmann::json_editable_document edited = nlohmann::json_editable_document::parse(R"({"a":[1,2,3],"b":{"c":"d"},"e":0.5})");
+        const json_document plain = json_document::parse(R"({"a":[1,2,3,4],"b":{"c":"x","y":null},"e":0.5,"z":[]})");
+        edited.push_back(edited.root()["a"], 4);
+        edited.set(edited.root()["b"], "c", "x");
+        edited.set(edited.root()["b"], "y", nullptr);
+        edited.set(edited.root(), "z", json::array());
+        CHECK(edited.root() == plain.root());
+        CHECK(plain.root() == edited.root());
+        edited.erase(edited.root()["a"], 0);
+        CHECK(edited.root() != plain.root());
+        CHECK(edited.root()["a"] == json::parse("[2,3,4]"));
+        const json_document tail = json_document::parse("[2,3,4]");
+        CHECK(edited.root()["a"] == tail.root());
+    }
+
+    SECTION("large documents, with a difference at any place")
+    {
+        const auto make = [](std::size_t count, std::size_t changed, bool swap_members)
+        {
+            std::string text = R"({"b":1,"list":[)";
+            for (std::size_t i = 0; i < count; ++i)
+            {
+                text += (i != 0 ? "," : "");
+                const std::string id = std::to_string(i == changed ? i + 1 : i);
+                text += swap_members && i % 3 == 0 ? R"({"v":[1.5,"s",{"k":)" + id + R"(}],"id":)" + id + "}" : R"({"id":)" + id + R"(,"v":[1.5,"s",{"k":)" + id + "}]}";
+            }
+            return text + R"(],"a":{"y":2,"x":3}})";
+        };
+        const std::size_t count = 3000;
+        for (const std::size_t changed :
+                {
+                    count, std::size_t{0}, std::size_t{1}, count / 2, count - 1
+                })
+        {
+            for (const bool swap :
+                    {
+                        false, true
+                    })
+            {
+                CAPTURE(changed)
+                CAPTURE(swap)
+                const std::string text_a = make(count, count, false);
+                const std::string text_b = make(count, changed, swap);
+                const json_document a = json_document::parse(text_a);
+                const json_document b = json_document::parse(text_b);
+                const bool equal = changed == count;
+                CHECK((a.root() == b.root()) == equal);
+                CHECK((b.root() == a.root()) == equal);
+                CHECK((a.root() == json::parse(text_b)) == equal);
+                CHECK((json::parse(text_b) == a.root()) == equal);
+                CHECK((a.root()["list"] == b.root()["list"]) == equal);
+                const ordered_json_document oa = ordered_json_document::parse(text_a);
+                const ordered_json_document ob = ordered_json_document::parse(text_b);
+                CHECK((oa.root() == ob.root()) == (equal && !swap));
+                CHECK((oa.root() == ordered_json::parse(text_b)) == (equal && !swap));
+            }
+        }
+    }
+
     SECTION("deep nesting")
     {
         const std::string deep = std::string(100000, '[') + std::string(100000, ']');
@@ -600,142 +748,6 @@ TEST_CASE("json_view large objects")
         CHECK(without_collisions.memory_usage() >= with_collisions.memory_usage() + (table_size * sizeof(std::uint32_t)));
     }
 
-    SECTION("keys that differ in their last bytes are spread over the table")
-    {
-        // The hash must spread the usual families of keys (numbered names, hex
-        // strings, dates, short names): a key farther than index_max_displacement
-        // from its home slot would leave the object without a table. The keys
-        // are placed with linear probing, as the table does.
-        const auto max_displacement = [](const std::vector<std::string>& keys)
-        {
-            std::size_t slots = 16;
-            while (slots < 2 * keys.size())
-            {
-                slots *= 2;
-            }
-            std::vector<bool> used(slots, false);
-            std::size_t farthest = 0;
-            for (const std::string& key : keys)
-            {
-                std::size_t i = static_cast<std::size_t>(nlohmann::detail::view::key_hash(key.data(), key.size())) & (slots - 1);
-                std::size_t distance = 0;
-                while (used[i])
-                {
-                    i = (i + 1) & (slots - 1);
-                    ++distance;
-                }
-                used[i] = true;
-                farthest = (std::max)(farthest, distance);
-            }
-            return farthest;
-        };
-        // the keys of a printf-like pattern with one %d, %0Nd or %0Nx, formatted with a stream
-        // (a format string that is not a literal is a Flawfinder error)
-        const auto numbered = [](const char* format, int count, int step)
-        {
-            const std::string pattern(format);
-            const std::size_t percent = pattern.find('%');
-            std::size_t conversion = percent + 1;
-            std::size_t width = 0;
-            while (pattern[conversion] >= '0' && pattern[conversion] <= '9')
-            {
-                width = width * 10 + static_cast<std::size_t>(pattern[conversion] - '0');
-                ++conversion;
-            }
-            const bool hex = pattern[conversion] == 'x';
-            std::vector<std::string> keys;
-            for (int i = 0; i < count; ++i)
-            {
-                std::ostringstream key;
-                key << pattern.substr(0, percent) << std::setfill('0') << std::setw(static_cast<int>(width))
-                    << (hex ? std::hex : std::dec) << i * step << pattern.substr(conversion + 1);
-                keys.push_back(key.str());
-            }
-            return keys;
-        };
-        for (const char* format :
-                {"key%d", "%d", "item_%04d", "a%05d", "%03dxyz", "id%d", "user_%d", "%d_suffix", "0x%04x", "A%07d", "12345678%d", "1234567%d", "123456789%d",
-                 "configuration_parameter_value_%04d_extra", "2026-01-%02dT00:00:00Z"
-                })
-        {
-            CAPTURE(format)
-            CHECK(max_displacement(numbered(format, std::string(format).find("%02d") != std::string::npos ? 60 : 1000, 1)) < nlohmann::detail::view::index_max_displacement);
-            CHECK(max_displacement(numbered(format, 600, 7)) < nlohmann::detail::view::index_max_displacement);
-        }
-        std::mt19937_64 rng(7);
-        for (const std::size_t length :
-                {
-                    std::size_t{1}, std::size_t{2}, std::size_t{3}, std::size_t{5}, std::size_t{7}, std::size_t{8}, std::size_t{9}, std::size_t{12}, std::size_t{16}, std::size_t{17}, std::size_t{33}
-                })
-        {
-            CAPTURE(length)
-            std::set<std::string> distinct;
-            while (distinct.size() < (length == 1 ? 26 : (length == 2 ? 500 : 700))) // (there are 26 and 676 keys of one and two letters)
-            {
-                std::string key(length, 'a');
-                for (char& c : key)
-                {
-                    c = static_cast<char>('a' + (rng() % 26));
-                }
-                distinct.insert(key);
-            }
-            CHECK(max_displacement(std::vector<std::string>(distinct.begin(), distinct.end())) < nlohmann::detail::view::index_max_displacement);
-        }
-    }
-
-    SECTION("keys of every length that differ in one byte")
-    {
-        // In a large object, a key is found by comparing its bytes with those of the member the
-        // table points to: up to 16 bytes as two overlapping words, longer ones with memcmp.
-        // Keys of every length from 0 to 40, and keys that differ from them in one byte.
-        std::mt19937_64 rng(2026);
-        std::vector<std::string> keys;
-        std::set<std::string> distinct;
-        for (std::size_t length = 0; length <= 40; ++length)
-        {
-            for (int copy = 0; copy < 5; ++copy)
-            {
-                std::string key(length, 'a');
-                for (char& c : key)
-                {
-                    c = static_cast<char>('a' + (rng() % 26));
-                }
-                if (distinct.insert(key).second)
-                {
-                    keys.push_back(key);
-                }
-            }
-        }
-        std::string text = "{";
-        for (std::size_t i = 0; i < keys.size(); ++i)
-        {
-            text += (i != 0 ? ",\"" : "\"") + keys[i] + "\":" + std::to_string(i);
-        }
-        text += "}";
-        REQUIRE(keys.size() >= 128); // (a table is built for 128 members)
-        const json_document d = json_document::parse(text);
-        const json_view v = d.root();
-        for (std::size_t i = 0; i < keys.size(); ++i)
-        {
-            CAPTURE(keys[i])
-            CHECK(v[keys[i]].get<std::size_t>() == i);
-            CHECK(v.at(keys[i]).get<std::size_t>() == i);
-            CHECK(v.contains(keys[i]));
-            for (std::size_t at = 0; at < keys[i].size(); ++at)
-            {
-                std::string other = keys[i];
-                other[at] = other[at] == 'z' ? 'y' : 'z';
-                CAPTURE(other)
-                CHECK(v.contains(other) == (distinct.count(other) != 0));
-            }
-            CHECK(v.contains(keys[i] + "a") == (distinct.count(keys[i] + "a") != 0));
-            if (!keys[i].empty())
-            {
-                CHECK(v.contains(keys[i].substr(1)) == (distinct.count(keys[i].substr(1)) != 0));
-            }
-        }
-    }
-
     SECTION("shrink_to_fit releases the tables' spare capacity")
     {
         const auto make_text = [](int objects, int members)

tests/src/unit-json_view_edit.cpp

@@ -661,115 +661,6 @@ TEST_CASE("json_view edits: replacing arrays and objects by scalars")
     CHECK(d.root().materialize() == expected);
 }
 
-TEST_CASE("json_view edits: arrays whose elements have no subtrees")
-{
-    // such an array is indexed directly while it is in its parsed layout; edits
-    // that replace elements by scalars keep it, others move it
-    json_editable_document d = json_editable_document::parse("[10,20,30,40]");
-    json expected = json::array({10, 20, 30, 40});
-    const auto check = [&]
-    {
-        CHECK(d.root().size() == expected.size());
-        for (std::size_t i = 0; i < expected.size(); ++i)
-        {
-            CHECK(d.root()[i].materialize() == expected[i]);
-            CHECK(d.root().at(i).materialize() == expected[i]);
-        }
-        CHECK(d.root()[expected.size()].is_discarded());
-        CHECK(d.root().back().materialize() == expected.back());
-        CHECK(d.root().dump() == expected.dump());
-    };
-    check();
-    d.set(d.root()[1], "x");
-    expected[1] = "x";
-    check();
-    d.set(d.root()[3], 2.5);
-    expected[3] = 2.5;
-    check();
-    d.set(d.root()[2], json::array({1, 2}));
-    expected[2] = json::array({1, 2});
-    check();
-    d.push_back(d.root(), 50);
-    expected.push_back(50);
-    check();
-    d.insert(d.root(), 0, true);
-    expected.insert(expected.begin(), true);
-    check();
-    d.erase(d.root(), 1);
-    expected.erase(expected.begin() + 1);
-    check();
-    d.set(d.root()[2], nullptr);
-    expected[2] = nullptr;
-    check();
-}
-
-TEST_CASE("json_view edits: materializing values nested deeper than the document was parsed")
-{
-    // the stack of open containers of materialize() is sized from the nesting of the parsed text;
-    // a value added by an edit can be deeper than that (and than the stack that is local to the call)
-    json_editable_document d = json_editable_document::parse("[1,[2]]");
-    json expected = json::array({1, json::array({2})});
-    json nested = 3;
-    for (int level = 0; level < 40; ++level)
-    {
-        nested = json::array({nested, json{{"k", level}}});
-    }
-    d.push_back(d.root(), nested);
-    expected.push_back(nested);
-    CHECK(d.root().materialize() == expected);
-    CHECK(d.root()[2].materialize() == nested);
-    d.set(d.root()[1][0], nested);
-    expected[1][0] = nested;
-    CHECK(d.root().materialize() == expected);
-    CHECK(d.root().get<json>() == expected);
-}
-
-TEST_CASE("json_view edits: an editable document before and after its first edit")
-{
-    // until the first edit, an editable document is read like a read-only one; views made before the edit
-    // keep working after it
-    const std::string text = R"({"a":[1,2,{"x":"y"},4],"b":{"c":true,"d":null},"e":"text","f":[]})";
-    const json_document read_only = json_document::parse(text);
-    json_editable_document d = json_editable_document::parse(text);
-    const auto root = d.root();
-    const auto same_as_read_only = [&]
-    {
-        CHECK(root.dump() == read_only.root().dump());
-        CHECK(root.dump(2) == read_only.root().dump(2));
-        CHECK(root.materialize() == read_only.root().materialize());
-        CHECK(root["a"][2]["x"].get_string() == "y");
-        CHECK(root["a"].at(3).get<int>() == 4);
-        CHECK(root["a"].back().get<int>() == 4);
-        CHECK(root.contains("b"));
-        CHECK(!root.contains("zz"));
-        CHECK(root.find("e")->get_string() == "text");
-        CHECK(root.find("zz") == root.end());
-        CHECK(root["b"]["c"].get<bool>());
-        CHECK(root.value("e", "none") == "text");
-        std::size_t count = 0;
-        for (const auto m : root["a"])
-        {
-            CHECK(m.materialize() == read_only.root()["a"][count].materialize());
-            ++count;
-        }
-        CHECK(count == 4);
-    };
-    same_as_read_only();
-    // an edit that changes a scalar in place, then one that moves an array
-    d.set(root["e"], "other");
-    CHECK(root["e"].get_string() == "other");
-    CHECK(root["a"][2]["x"].get_string() == "y");
-    CHECK(root["a"].back().get<int>() == 4);
-    d.push_back(root["f"], 7);
-    CHECK(root["f"][0].get<int>() == 7);
-    CHECK(root["f"].back().get<int>() == 7);
-    CHECK(root.dump() == R"({"a":[1,2,{"x":"y"},4],"b":{"c":true,"d":null},"e":"other","f":[7]})");
-    d.set(root["a"], 2, json::array({1, 2}));
-    CHECK(root["a"][2][1].get<int>() == 2);
-    CHECK(root["a"].dump() == "[1,2,[1,2],4]");
-    CHECK(root.materialize() == json::parse(R"({"a":[1,2,[1,2],4],"b":{"c":true,"d":null},"e":"other","f":[7]})"));
-}
-
 namespace
 {
 // reads of "a" in an object that repeats it: the first member wins, however the

tests/src/unit-json_view_image.cpp

@@ -682,6 +682,66 @@ TEST_CASE("json_view images: ownership")
 #if !defined(JSON_NOEXCEPTION)
 TEST_CASE("json_view images: errors")
 {
+#if !defined(JSON_NOEXCEPTION)
+    SECTION("float tokens: a changed byte is accepted if the text is still a number with the digits the node records")
+    {
+        for (const char* const token :
+                {
+                    "-12.375", "0.5", "123456.0", "-0.0", "9999999999999999999.5", "0.000000000000000000000001", "1.25e10", "5E-3"
+                })
+        {
+            CAPTURE(token)
+            const std::string text = std::string("[") + token + "]";
+            const json_document d = json_document::parse(text);
+            const std::vector<std::uint8_t> image = d.save();
+            const std::size_t at = text_at(image) + 1; // the first byte of the token
+            const std::uint16_t recorded = node_at(image, 1).extra;
+            CHECK(loaded_dump(image) == json::parse(text).dump());
+            for (std::size_t pos = 0; token[pos] != '\0'; ++pos)
+            {
+                for (unsigned int byte = 0; byte < 256; ++byte)
+                {
+                    std::vector<std::uint8_t> changed = image;
+                    changed[at + pos] = static_cast<std::uint8_t>(byte);
+                    std::string t = token;
+                    t[pos] = static_cast<char>(byte);
+                    // the digits of the integer part and of the fraction of the changed token
+                    std::size_t integer = 0;
+                    std::size_t fraction = 0;
+                    std::size_t k = (t[0] == '-') ? 1 : 0;
+                    for (; k < t.size() && t[k] >= '0' && t[k] <= '9'; ++k)
+                    {
+                        ++integer;
+                    }
+                    if (k < t.size() && t[k] == '.')
+                    {
+                        for (++k; k < t.size() && t[k] >= '0' && t[k] <= '9'; ++k)
+                        {
+                            ++fraction;
+                        }
+                    }
+                    // (as a JSON text, the token may have white space around it)
+                    const bool float_token = json::accept(t) && t.find_first_of(std::string(" \t\r\n\0", 5)) == std::string::npos && (t.find('.') != std::string::npos || t.find_first_of("eE") != std::string::npos)
+                                             && ((integer | (fraction << 8U)) == recorded);
+                    CAPTURE(pos)
+                    CAPTURE(byte)
+                    std::string result;
+                    try
+                    {
+                        result = loaded_dump(changed);
+                    }
+                    catch (const json::parse_error& e)
+                    {
+                        CHECK(std::string(e.what()) == check_failed);
+                        result = "rejected";
+                    }
+                    CHECK((result != "rejected") == float_token);
+                }
+            }
+        }
+    }
+#endif
+
     SECTION("a literal as the root: dump() after loading")
     {
         for (const char* text :