Commit Graph

24 Commits

Author SHA1 Message Date
Niels Lohmann
58706fdba0 Merge branch 'json-view/16-view-simd' into json-view/18-view-object-index
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 23:26:38 +02:00
Niels Lohmann
1d9246e8f4 Merge branch 'json-view/14-view-compare' into json-view/14b-view-float-layout
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:47:28 +02:00
Niels Lohmann
1a8546849e Merge branch 'json-view/13-view-dump' into json-view/14-view-compare
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:46:19 +02:00
Niels Lohmann
79bf60b44b Merge branch 'json-view/12-view-values' into json-view/13-view-dump
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:45:09 +02:00
Niels Lohmann
9549dce77b Fix CI: value-initialize a const json_view for clang 3.6
clang 3.6 rejects `const json_view invalid;` (no user-provided default
constructor, CWG 253), as fixed in json-view/10-view-document.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:44:44 +02:00
Niels Lohmann
a210437b30 Fix CI: json_view value tests without exceptions and with GCC
- ci_test_noexceptions: exception_of() and without_path() exist only
  with exceptions (they catch outside a CHECK_THROWS, which aborts with
  JSON_NOEXCEPTION); compile the comparisons of the conversion, value(),
  and JSON pointer errors only with exceptions as well.
- ci_test_gcc: -Werror=unused-result for static_cast<void>(j.contains(p))
  (GCC's warn_unused_result ignores a cast to void); store the result.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:44:33 +02:00
Niels Lohmann
fdcba786d8 Merge branch 'json-view/11-view-access' into json-view/12-view-values
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:42:18 +02:00
Niels Lohmann
958fbc3702 Fix CI: json_view access tests without exceptions and on clang 3.6
- ci_test_noexceptions: the element access tests compare the exceptions
  of json_view and basic_json through exception_of(), which catches them
  outside a CHECK_THROWS; with JSON_NOEXCEPTION the first one aborted the
  test. Compile those comparisons only with exceptions.
- clang 3.6: value-initialize a const json_view, as in the tests of
  json-view/10-view-document.
- Format three new documentation examples with the pinned astyle, which
  the "check" job runs once it gets past the amalgamation step.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:41:59 +02:00
Niels Lohmann
0dfd1c938e Merge branch 'json-view/10-view-document' into json-view/11-view-access
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:39:38 +02:00
Niels Lohmann
a8e9ce9417 Fix CI: json_view tests without exceptions, on clang 3.6, and single header
- ci_test_noexceptions: the helpers that compare the exceptions of
  json_document::parse() and json::parse() catch them outside a
  CHECK_THROWS, so with JSON_NOEXCEPTION the first parse error aborted
  the test. Compile those comparisons only with exceptions, as
  unit-class_parser.cpp does.
- ci_test_gcc: -Werror=unused-result for CHECK_THROWS_AS(json_document::
  parse(...)); assign the result to a dummy document.
- ci_test_compilers_clang (3.6): `const json_view invalid;` needs a
  user-provided default constructor there (CWG 253); value-initialize it.
- ci_test_single_header: json_view.hpp now exists as a single header and
  contains the internal view headers, so unit-json_view_builder.cpp
  includes it instead of the detail headers in that mode, and the test
  is built again with the single header.
- Regenerate single_include/nlohmann/json_view.hpp for the builder change
  merged from json-view/08-view-builder.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:39:30 +02:00
Niels Lohmann
0d59ae5d49 Address the clang-tidy findings of the object index tests
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:03:08 +02:00
Niels Lohmann
61b104606d Index the large objects of json_view
Lookups in objects are linear, as for ordered_json. Objects with 128
members or more now get a hash table after parsing (open addressing; the
first of duplicate keys is kept, as for the linear search), so that
operator[], at(), find(), contains(), count(), value(), and JSON pointers
take constant time on average in them; the idea of switching to a hash
table for large objects is Boost.JSON's. The parser notes such objects when
it closes them (out of line, so that the parse loop only has a call for
it), and the object node keeps the number of its table.

Looking up each key of an object with 10,000 members: 59.8 ms -> 0.16 ms.
Parsing (json_document::parse, best of 7, separate processes): most files
within 1%; canada +5%, mesh.pretty +3%, citm +3%.

Tests: objects with 127, 128, 129, and 10,000 members (escaped, empty,
and duplicate keys, missing keys, comparisons), nested large objects, and
documents reused with read().

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:03:07 +02:00
Niels Lohmann
bf6b5b4719 Convert the floats of json_view from the digit layout
The parser records where the integer digits, the fraction digits, and the
exponent of a float token are. For doubles with at most 19 digits, the
value is now read from that layout: the digits eight at a time, without
scanning the token, and rounded with Clinger's fast path where both
operands are exact, else with the Eisel-Lemire algorithm (which needs no
fallback for up to 19 digits). Both round correctly, so the values are
those of parse(); other tokens and types keep the library's conversion.

get<double>(), materialize(), dump(), and comparisons use it. Traversing
canada.json (111,000 floats, every number converted): 0.53 -> 0.86 GB/s.

Tests add tokens around the limits (19 and 20 digits, 2^53, 10^22) to the
bit-for-bit comparison with parse().

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:03:02 +02:00
Niels Lohmann
20fd4c6a8b Address the clang-tidy findings of the comparisons
Separate the comparison of discarded values from the other types, so
that the conditional chain has no repeated branch bodies, and mark
the deliberate comparisons of views with empty containers in the
tests.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:03:01 +02:00
Niels Lohmann
401af52511 Add comparisons to json_view
basic_json_view gains operator== and operator!= with other views and with
basic_json values. Two views are equal if the values parse() would
produce for them are equal by basic_json's operator==: numbers compare by
value across their types, and objects by their members, with duplicate
keys resolved as parse() resolves them (the last value, at the position of
the first key). Objects are compared in member order if the object type
keeps an order (ordered_json), by key otherwise, as basic_json does.
Discarded views compare as discarded basic_json values do, which follows
JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON. Nothing is materialized except
single numbers, and the walk is iterative.

Tests compare the results for pairs of 1,200 generated documents (also
written differently: sorted keys, canonical numbers) with those of
basic_json, for json and ordered_json, plus numbers, duplicate keys,
member order, discarded values, and 100,000 levels of nesting.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:59 +02:00
Niels Lohmann
1318023103 Address the clang-tidy findings of dump()
The output buffer initializes its members in the initializer list, and the
escaping has no nested conditional operators; the test marks a fixed seed.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:57 +02:00
Niels Lohmann
1ef0582ed7 Add dump() to json_view
basic_json_view::dump(indent, indent_char, ensure_ascii, number_format)
writes the text of a value as ordered_json::parse(text).dump() writes it
for the same arguments: members in document order (all of them, should a
key occur more than once), strings escaped by the same rules and with the
library's scanning kernels, floats with the library's conversion, and
integers copied from the source, where they are canonical except "-0".
With number_format::source, numbers are copied as they appear in the
source ("1.50", "1E2", "-0", all digits of long integers). operator<<
takes the indentation from the stream width, as for basic_json.

The writer (detail/view/serializer.hpp) writes through a raw pointer into
a string sized from the source extent of the value, and walks the index
iteratively, so the nesting depth is limited by memory only.

Tests compare the output of 2,000 generated documents with
ordered_json::dump() for several indentations and ensure_ascii, strings
with every kind of escape, numbers (5,000 random doubles, float as
number_float_t), duplicate keys, 100,000 levels of nesting, and streams.
ViewDump joins the benchmarks.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:56 +02:00
Niels Lohmann
bc36fd323b Address the clang-tidy findings of values and JSON pointers
get_string() and number_token() return braced lists; the test compares
floats by their bit patterns instead of with memcmp, uses std::any_of, and
marks a fixed seed, a default member initializer (needed by GCC's
-Weffc++), and a string search.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:54 +02:00
Niels Lohmann
85f414ae7a Add values and JSON pointers to json_view
basic_json_view gains get<T>(), get_to(), value() with keys and JSON
pointers, and operator[], at(), and contains() with JSON pointers, plus
two functions basic_json has no counterpart for:

- get_string(): the string without a copy (a string_view into the source,
  or into the decoded strings for strings with escapes)
- number_token(): the text of a number as it appears in the source

get<T>() converts arithmetic types, strings (also string_view_t),
std::nullptr_t, std::vector, maps with string keys, and views directly;
floats are converted from the digit layout recorded by the parser with the
library's conversion chain, so the values are bit-identical to parse().
Other types, including user types with from_json(), go through
materialize().

The exceptions are those of basic_json, message included. Where const
basic_json has undefined behavior (a missing key or an index out of range
with operator[] and a JSON pointer), the result is a discarded view;
value() returns the default wherever basic_json catches out_of_range, and
contains() never throws. Array indices of JSON pointers follow
json_pointer's rules (parse_error.106/109, out_of_range.404/410).

Tests compare the conversions of 2,000 generated documents, 20,000 float
tokens (double and float, bit for bit), and every JSON pointer of 1,000
documents with basic_json, and the exceptions for malformed pointers.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:52 +02:00
Niels Lohmann
daad8ea9b5 Address the clang-tidy findings of element access and iteration
Marks the default initializer of the item's index string (needed by GCC's
-Weffc++) and, in the test, an escaped literal and a comparison of find()
with end(), which is what the test is about.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:51 +02:00
Niels Lohmann
f80a1a17a9 Add element access, lookup, and iteration to json_view
basic_json_view gains the read-only access functions of basic_json:
operator[] and at() with keys and indices, front(), back(), find(),
contains(), count(), begin()/end(), items() (with structured bindings from
C++17 on), and type_name(). They throw the exceptions (ids and messages)
that the const functions of basic_json throw; where basic_json has
undefined behavior (operator[] with a missing key or an index out of
range, front()/back() of an empty container), the view returns a
discarded view or throws invalid_iterator.214.

Objects are iterated in document order, and all members are visited. With
duplicate keys, lookups find the first member, so that a lookup can stop
at the first match; parse() keeps the last value. Keys of up to 16 bytes
are compared with two overlapping loads instead of memcmp, and most keys
are rejected by their length alone, from the index.

The iterators and items live in detail/view/iterator.hpp, the lookups in
detail/view/lookup.hpp. Tests compare every element and member of 2,000
generated documents with ordered_json, keys of every length around the
load sizes, the exceptions against const basic_json, and the iterators.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:49 +02:00
Niels Lohmann
207fc01576 Mark the code of json_view that tests cannot reach
The 4 GiB limit and the fallback for an input that parse() accepts but
the view rejects (a bug) are excluded from the coverage; shrink_to_fit()
of an empty document is tested.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:46 +02:00
Niels Lohmann
aa1a0c7561 Address the clang-tidy findings of json_document and json_view
- the input dispatch takes byte ranges by const reference and reads the
  size once (which also settles a finding of the static analyzer); input
  adapters are taken by value
- the classification of inputs keeps its nested conditional operators, a
  constant expression of C++11 (NOLINT)
- the test's C arrays, fixed seed, and escaped literals are marked, as in
  the other tests

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 14:02:45 +02:00
Niels Lohmann
7b30f0acb2 Test json_document and json_view
unit-json_view.cpp: type queries, size, and empty against basic_json;
materialize() against parse() (json and ordered_json, generated documents,
duplicate keys, 100,000 levels of nesting, parent pointers with
JSON_DIAGNOSTICS); parse errors and their messages equal to parse() for
malformed inputs and all option combinations; NUL and BOM; borrowed and
owned inputs (strings, C strings, literals, vectors, string_view, streams,
wide strings, parse_copy, and iterator ranges over pointers, vectors,
strings, and lists); reuse with read(); moves; shrink_to_fit() of the index
and of the decoded strings; source offsets.

unit-json_view_macros.cpp includes the header without
JSON_TEST_KEEP_MACROS, as users do: the view must not depend on the macros
json.hpp undefines, and must not leak its own.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 09:54:05 +02:00