* Add FracturedJson formatting support for DOM serialization
Implements FracturedJson formatting as requested in issue #2576.
FracturedJson produces human-readable yet compact JSON output by
intelligently choosing between different layout strategies based on
content complexity, length, and structure similarity.
Key features:
- Four layout modes: inline, compact multiline, table, and expanded
- Structure analysis pass to compute metrics before formatting
- Table formatting for arrays of similar objects with column alignment
- Configurable options for line length, indentation, padding, etc.
New files:
- fractured_json.h: Public API with fractured_json_options struct
- fractured_json-inl.h: Implementation (~1000 lines)
- json_structure_analyzer.h: Structure analysis for layout decisions
- fractured_formatter.h: Formatter class using CRTP pattern
Usage:
dom::parser parser;
element doc = parser.parse(json_string);
std::cout << fractured_json(doc) << std::endl;
// Or with custom options:
fractured_json_options opts;
opts.indent_spaces = 2;
std::cout << fractured_json(doc, opts) << std::endl;
// Or format any JSON string (useful with reflection API):
auto formatted = fractured_json_string(minified_json);
Resolves#2576
* Add comprehensive tests for FracturedJson formatter
Adds 27 test cases covering all aspects of the FracturedJson formatter:
Core functionality tests (13):
- Roundtrip parsing verification
- Inline formatting for simple arrays and objects
- Expanded formatting for complex nested structures
- Compact multiline arrays with configurable items per line
- Table formatting for uniform arrays of objects
- Empty container handling
- All scalar types (string, int, uint, double, bool, null)
- String escaping (quotes, backslashes, control characters)
- Custom indentation options
- Deep nesting (10+ levels)
- Mixed type arrays
Edge case tests (11):
- Unicode strings (Chinese, emoji, Arabic, Russian, accented chars)
- Boundary numbers (INT64_MIN/MAX, UINT64_MAX, DBL_MIN/MAX)
- Nested arrays (arrays of arrays)
- Empty string values
- Keys with special characters (spaces, quotes, colons, etc.)
- Non-uniform arrays (should not trigger table mode)
- Very long strings (500+ chars)
- Large arrays (100 elements)
- Reflection API workflow simulation
- Control characters (tab, newline, CR, null)
- Single element containers
Option tests (3):
- Disable compact multiline mode
- Disable table format mode
- Disable all padding options
* Add FracturedJson integration with builder/reflection API
Extends FracturedJson to work seamlessly with the builder API, enabling
formatted output directly from C++ structs using static reflection.
New functions:
- to_fractured_json_string(obj, opts) - serialize struct to formatted JSON
- to_fractured_json(obj, output, opts) - same with output parameter
- extract_fractured_json<fields...>(obj, opts) - format only specific fields
These functions combine the builder's reflection-based serialization with
FracturedJson formatting in a single convenient call:
struct User { int id; std::string name; bool active; };
User user{1, "Alice", true};
// Minified output (existing):
auto minified = to_json_string(user);
// {"id":1,"name":"Alice","active":true}
// Formatted output (new):
auto formatted = to_fractured_json_string(user);
// { "id": 1, "name": "Alice", "active": true }
// Partial extraction with formatting:
auto partial = extract_fractured_json<"id", "name">(user);
// { "id": 1, "name": "Alice" }
New files:
- generic/builder/fractured_json_builder.h - builder integration
- tests/builder/static_reflection_fractured_json_tests.cpp - 7 tests
* Fix INT64_MIN overflow and implement table_similarity_threshold
- Fix undefined behavior when negating INT64_MIN in estimate_number_length()
and measure_value_length() by returning 20 (the exact length of the
string representation) directly
- Actually use table_similarity_threshold in check_array_uniformity() by
calling compute_object_similarity() to compare objects against the first
object in the array
* Fix -Werror=effc++ member initialization warnings
Initialize all member variables in member initialization lists to
satisfy GCC's -Werror=effc++ flag:
- element_metrics::common_keys - add {} default initializer
- structure_analyzer - add default constructor with member init list
- fractured_formatter - add column_widths_{} to constructor
- fractured_string_builder - add analyzer_{} to constructor
* Add Rule of Five to structure_analyzer class
The class has a pointer member (current_opts_) which triggers
-Werror=effc++ requiring explicit copy/move operations. Delete
copy operations (class shouldn't be copied due to cache) and
default move operations.
* Fix Windows build: wrap std::max to avoid macro conflict
Windows.h defines max/min macros that interfere with std::max/std::min.
Wrapping in parentheses as (std::max)(...) prevents macro expansion.
* Fix GCC 15 false positive -Wfree-nonheap-object warning
GCC 15 on MINGW64 gives a false positive warning in parser_moving_parser()
when the std::vector<std::string> goes out of scope. Suppress this
specific warning with a pragma for GCC builds.
* Fix metrics cache key bug by passing metrics through recursion
The cache was using element addresses as keys, but dom::element objects
are lightweight wrappers that get copied during iteration, causing
different addresses between analysis and formatting phases. This resulted
in cache misses and fallback to empty metrics.
Solution: Store child metrics in the element_metrics struct and pass
them through recursive calls, eliminating the need for address-based
caching entirely.
Changes:
- Add children vector to element_metrics for hierarchical metrics
- Remove metrics_cache_ and related get_metrics/has_metrics methods
- Update all format functions to accept and pass child metrics
- Add public analyze_array/analyze_object overloads for standalone use
* Add ignore patterns for Node.js, Rust, and generated files
Add entries for node_modules, package-lock.json, Rust target
directories, local ablation artifacts, and generated documentation
files.
* Refactor: extract analyze_scalar helper to reduce code duplication
Extract common scalar type handling (STRING, INT64, UINT64, DOUBLE,
BOOL, NULL_VALUE) into a dedicated analyze_scalar method. Each scalar
type shares the same initialization pattern for complexity, child_count,
can_inline, and recommended_layout.
Also simplify boolean formatting in format_scalar to use ternary operator.
* Fix formatting and duplicate error message in amalgamate.py
Reformat cramped is_amalgamator condition to multi-line for readability.
Fix duplicate error message text in _included_filename_root and use
correct variable name (relative_root instead of root).
* Refactor: add count_newlines helper in fractured_json tests
Extract repeated newline counting loop into a reusable static helper
function, used by inline_array_test, inline_object_test, and
expanded_test.
* Revert "Add ignore patterns for Node.js, Rust, and generated files"
This reverts commit 4760ea7cd0.
* various minor changes
---------
Co-authored-by: Daniel Lemire <daniel@lemire.me>
* Initial work on JSON builder
* moving the files back to ondemand for now.
* tweak
* more later
* update
* minor edits
* dropping vs arm (missing support)
* adding tests. we still specialized write_string_escaped
* tweaking
* fix typo
* tweaking the approach
* minor fix
* missing store
* another missing store
* Attempt at fixing failing serialization tests. (#2292)
* Fixing appeand_float typo (#2294)
* applying a couple of fixes
* updating single header
* fix for pre C++17 if constexpr
* Fixing unused argument problem and updating the singleheader file
* various pedantic fixes
* Sketch of builder
* reordering.
* simplify
* Adding draft of static reflection based deserialization
* Updating simdjson singleheader
* patching the automated deserialization.
* automated
* Adding support for smart pointers of user defined types.
* Adding specialization for smart pointers for basic types. I think it is highly likely that this can be done in a more generic way.
* Referncing a later version of rapidjson that fixed the issue related with assignment attempt of a const variable for GenericStringRef class.
* guarding the tests
* adding documentation for string_builder
* saving
* rename to 'append'
* saving
* non-functional benchmarks (#2342)
* non-functional benchmarks
* Fix typo
* various fixes
* tweaking
---------
Co-authored-by: Daniel Lemire <dlemire@lemire.me>
Co-authored-by: Francisco Geiman Thiesen <franciscogthiesen@gmail.com>
* tuning
* various minor fixes
* minor tweak
* minor simplification
* updating amal
* adding a cast
* update
* fancy casting
* removing dead code
* Pushing latest changes. CITM benchmark is still not working.
* Still not working, but now I am getting only 10 errors.
* add static reflection benchmark to 'large random' benchmark and allows (#2349)
deserialization (with static reflection) from objects and arrays.
Co-authored-by: Daniel Lemire <dlemire@lemire.me>
* Removing std::map from CitmCatalog definition, since that is not currently supported.
* Added free to rust bench, segfault is still happening..
* The syntax changed: ^E became ^^E. (#2350)
* The syntax changed: ^E became ^^E.
* guarding
---------
Co-authored-by: Daniel Lemire <dlemire@lemire.me>
* Adding support for string_view_keyed_map types.
* Adding concepts as a conditional include.
* updating single-header
* Adding concepts to ondemand deps
* rust benchmark is finally working
* Fixing small typo in docs.
* adding docker config and instructions so that our users can test the static reflection (#2358)
* adding docker config and instructions so that our users can test the
static reflection
* completing the instructions
* pruning white spaces
---------
Co-authored-by: Daniel Lemire <dlemire@lemire.me>
* minor optimizations on the JSON builder branch
* avoiding undef behaviour
* saving
* somewhat nicer builder
* make it possible to run just one benchmark
* adding linux perf
* fixing minor issue
* updating swar
* Adding real world compilation benchmark (#2379)
* Adding compilation benchmark for json parsing with and without reflection
* Moving it to the benchmark folder, also reducing a bit the number of iterations.
* Removing script from root folder.
* Reducing number of iterations
* Update benchmark/benchmark_reflection_usage_compilation.sh
Co-authored-by: Daniel Lemire <daniel@lemire.me>
* Update benchmark/benchmark_reflection_usage_compilation.sh
Co-authored-by: Daniel Lemire <daniel@lemire.me>
* Update benchmark/benchmark_reflection_usage_compilation.sh
Co-authored-by: Daniel Lemire <daniel@lemire.me>
* Making the script more customizable and also test whether the compiler being used supports reflection before actually running the benchmark
---------
Co-authored-by: Daniel Lemire <daniel@lemire.me>
* Using define_static_string from https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3491r2.html (#2389)
* Applying changes needed after latest reflection paper updates.
* Working, but no template for yet.
* Updating single-header to incldue the use of define_static_string.
* copying over master
---------
Co-authored-by: Daniel Lemire <dlemire@lemire.me>
Co-authored-by: Francisco Geiman Thiesen <franciscogthiesen@gmail.com>
* This moves all DOM (benchmark + test) files to a subdir
* Missing file.
* CMake + DLL is not pretty.
* Capitalizing AND
* Fixing mismatch endif
* Flipping the order.
* onedemand => ondemand
* Remove CMP0025 policy
This policy is already set to NEW by the minimum required version.
* Use HOMEPAGE_URL in the project call
* Use VERSION in the project call
* Detect if this is the top project
* Port simdjson-user-cmakecache to a CMake script
* Create a developer mode
The SIMDJSON_DEVELOPER_MODE option set to ON will enable targets that
are only useful for developers of simdjson.
* Consolidate root CML commands into logical sections
* Warn about intended use of developer mode
* Prettify the just_ascii test
* Remove redundant CMake variables
* Inline CML contents from include and src
* Raise minimum CMake requirement to 3.14
* Define proper install rules
* Restore thread support variable
* Add BUILD_SHARED_LIBS as a top level only option
* Force developer mode to be on in CI
* Include flags earlier in developer mode
* Set CMAKE_BUILD_TYPE conditionally
CMAKE_BUILD_TYPE is used only by single configuration generators and is
otherwise completely ignored.
* Remove useless static/shared options
simdjson now uses the CMake builtin BUILD_SHARED_LIBS to switch the
built artifact's type.
* Remove unused CMAKE_MODULE_PATH variable
* Refactor implementation switching into a module
* Factor exception option out into a module
* Reformat simdjson-flags.cmake
* Rename simdjson-flags to developer-options
* Accumulate properties into an include module
This is done this way to avoid using utility targets that must be
exported and installed, which could potentially be misused by users of
the library.
* Port impl definitions to props
* Port exception options to props
* Lift normal options to the top
* Port developer options to props
* Remove simdjson-flags from benchmark
* Document the developer mode in HACKING
* Fix include path in installed config file
* Fix formatting of prop commands
* Fix tests that include .cpp files
* Change GCC AVX fixes back to compile options
* Deprecate SIMDJSON_BUILD_STATIC
* Always link fuzz targets to simdjson
* Install CMake from simdjson's debian repo
* Add gnupg for apt-key
* Make sure ASan link flags come first
* Pass CI env variable to cmake invocation
* Install package for apt-add-repository
* Remove return() from flush macro
* Use directory level commands instead of props
* Restore the github repository variable
* Set developer mode unconditionally for checkperf
The CI env variable is only set in the CI and this target is always run
in developer mode.
* Attempt to fix ODR violation in parsing checks
These tests were compiling the simdjson.cpp file again and linking to
the simdjson library target causes ODR violations.
Instead of linking to the target, just inherit its props.
* Move variables before the source dir
* Mark props to be flushed after adding more
* Use props for every command for the library
* Use keyword form for linking libs
* Handle deprecation of SIMDJSON_JUST_LIBRARY
* Handle deprecations in a separate module
Co-authored-by: friendlyanon <friendlyanon@users.noreply.github.com>
* This gives the CMake install the necessarily information (and flags) to know
whether we have a Windows DLL and in such cases how to handle the linkage.
* Bump minimum CMake version
* Remove unnecessary git checks
* Move benchmark options where they are used
* Declare helper functions for dependencies
The custom solution here is tailored for fast configure times, but only
works for dependencies on Github.
* Import dependencies using the declared commands
* Remove git submodules
* Call target_link_libraries properly
target_link_libraries must not be called without a requirement
specifier.
* Fix includes for competition
Co-authored-by: friendlyanon <friendlyanon@users.noreply.github.com>
* add definitions for is_number and tie (by lemire)
* add fuzzer for element
* update fuzz documentation
* fix UB in creating an empty padded string
* don't bother null terminating padded_string, it is done by the std::memset already
* refactor fuzz data splitting into a separate class
* Remove our dependency on strtod_l by bundling our own slow path.
* Ok. Let us drop strtod entirely.
* Trimming down the powers to -342.
* Removing useless line.
* Many more comments.
* Adding some DLL exports.
* Let the gods help those who rely on windows+gcc.
* Marking the subnormals as unlikely. This is pretty much "performance neutral", but it might help just a bit with twitter.json.
* Adding new files.
* Better.
* Fixing minifier and adding tests.
* Adding benchmarks.
* Including the array header.
* Replacing old stream-based code by the new code.
* Doubling up the itoa.
* Hidden away to_chars in internal namespace.
* Removing the repetitions.
* Documented the atoi functions.
* Tuning the escape sequences.
* Moving the operators off the main namespace.
* Added more tests.
* Tweaking the implementation so that it works with and without exp.
* The string_builder template and mini_formatter class
are not part of our public API and are subject to change
at any time!
* Adding a benchmark and some optimization.
* Cleaning.
* Strictly speaking, this header is needed.
* Specification is not followed.
* Fixes.
* Do not pass string_view by reference.
* Better documentation.
* The example is written for exceptions.
* Better documentation.
* Updating with deprecation.
* Updating example.
* Updating example.
* This would disable bash scripts under FreeBSD.
* Let us also disable GIT.
* Let us try to just disable GIT
* Nope. We must have both bash and git disabled.
* The initial motivation behind basictests was for a quick set of sanity tests to check whether your code made sense. It
was not meant for thorough testing to find corner cases. However, over time, it grew to include such expensive tests.
This PR takes them out. It also allows us to bring back basictests to MinGW tests, since it is now cheap.
This is not an exercise in software engineering and making things prettier. This is a pragmatic change to improve our
test coverage and quality of life.
* Adds many more cheap tests.
Co-authored-by: Daniel Lemire <lemire@gmai.com>
* Testing with GCC 10 and clang 10
* Fixing spurious space
* gcc10 does not need the cmake installation.
* We don't want to run the perf test on ARM. I ignore them systematically. ARM performance
should be assessed manually.
* Switching to GCC 10 and Clang 10
* Disabling some tests under sanitizers when they involve rapidjson or other parsers.
Co-authored-by: Daniel Lemire <lemire@gmai.com>
To avoid using data belonging to a temporary, the parse functions are ref qualified to get a compile error if used on an rvalue. See https://github.com/simdjson/simdjson/issues/696
Compilation tests are also added, to make sure bad usage fails to compile.
Reviewed by jkeiser.
* Trying to correct the documentation so that it actually describes how the code behaves.
* tweaking the wording.
* Improving.
* Removing confusing sentence.
* Fixing formatting.
* Now with working example, tested.
* Added a smaller piece of code
Daniel Lemire