Added BSON support; #22

Author: liuzicheng1987

Diff for: .github/workflows/test.yaml

@@ -6,9 +6,11 @@ jobs:
   linux-gcc:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - name: Checkout
+        uses: actions/checkout@v3
         with:
-          submodules: true
+          submodules: recursive
+          fetch-depth: 0
       - name: Run vcpkg
         uses: lukka/run-vcpkg@v11
       - name: install dependencies
@@ -18,8 +20,9 @@ jobs:
       - name: Run test
         run: |
           g++ --version
-          cmake -S . -B build -DREFLECTCPP_BUILD_TESTS=ON -DREFLECTCPP_FLEXBUFFERS=ON -DREFLECTCPP_XML=ON -DREFLECTCPP_YAML=ON -DCMAKE_BUILD_TYPE=Release
+          cmake -S . -B build -DREFLECTCPP_BUILD_TESTS=ON -DREFLECTCPP_BSON=ON -DREFLECTCPP_FLEXBUFFERS=ON -DREFLECTCPP_XML=ON -DREFLECTCPP_YAML=ON -DCMAKE_BUILD_TYPE=Release
           cmake --build build -j 4
+          ./build/tests/bson/reflect-cpp-bson-tests
           ./build/tests/flexbuffers/reflect-cpp-flexbuffers-tests
           ./build/tests/json/reflect-cpp-json-tests
           ./build/tests/xml/reflect-cpp-xml-tests
@@ -28,9 +31,11 @@ jobs:
   linux-clang:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - name: Checkout
+        uses: actions/checkout@v3
         with:
-          submodules: true
+          submodules: recursive
+          fetch-depth: 0
       - name: Run vcpkg
         uses: lukka/run-vcpkg@v11
       - uses: KyleMayes/install-llvm-action@v1
@@ -47,8 +52,9 @@ jobs:
           CXX: clang++
         run: |
           clang --version
-          cmake -S . -B build -DREFLECTCPP_BUILD_TESTS=ON -DREFLECTCPP_FLEXBUFFERS=ON -DREFLECTCPP_XML=ON -DREFLECTCPP_YAML=ON -DCMAKE_BUILD_TYPE=Release
+          cmake -S . -B build -DREFLECTCPP_BUILD_TESTS=ON -DREFLECTCPP_BSON=ON -DREFLECTCPP_FLEXBUFFERS=ON -DREFLECTCPP_XML=ON -DREFLECTCPP_YAML=ON -DCMAKE_BUILD_TYPE=Release
           cmake --build build -j 4
+          ./build/tests/bson/reflect-cpp-bson-tests
           ./build/tests/flexbuffers/reflect-cpp-flexbuffers-tests
           ./build/tests/json/reflect-cpp-json-tests
           ./build/tests/xml/reflect-cpp-xml-tests

Diff for: .gitignore

@@ -41,6 +41,7 @@
 **/build_clang/**
 
 # Output files
+*.bson
 *.json
 *.fb
 *.xml

Diff for: CMakeLists.txt

@@ -1,14 +1,15 @@
 cmake_minimum_required(VERSION 3.15)
 
 option(REFLECTCPP_BUILD_SHARED "Build shared library" OFF)
+option(REFLECTCPP_BSON "Enable BSON support" OFF)
 option(REFLECTCPP_FLEXBUFFERS "Enable flexbuffers support" OFF)
 option(REFLECTCPP_XML "Enable XML support" OFF)
 option(REFLECTCPP_YAML "Enable YAML support" OFF)
 
 option(REFLECTCPP_BUILD_TESTS "Build tests" OFF)
 
 # enable vcpkg if require features other than JSON
-if (REFLECTCPP_FLEXBUFFERS OR REFLECTCPP_XML OR REFLECTCPP_YAML)
+if (REFLECTCPP_BSON OR REFLECTCPP_FLEXBUFFERS OR REFLECTCPP_XML OR REFLECTCPP_YAML)
     set(CMAKE_TOOLCHAIN_FILE ${CMAKE_CURRENT_SOURCE_DIR}/vcpkg/scripts/buildsystems/vcpkg.cmake CACHE STRING "Vcpkg toolchain file")
 endif ()
 
@@ -24,6 +25,11 @@ endif ()
 
 target_include_directories(reflectcpp PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
 
+if (REFLECTCPP_BSON)
+    find_package(bson-1.0 CONFIG REQUIRED)
+    target_link_libraries(reflectcpp PRIVATE $<IF:$<TARGET_EXISTS:mongo::bson_static>,mongo::bson_static,mongo::bson_shared>) 
+endif ()
+
 if (REFLECTCPP_FLEXBUFFERS)
     find_package(flatbuffers CONFIG REQUIRED)
     target_link_libraries(reflectcpp INTERFACE flatbuffers::flatbuffers)

Diff for: README.md

@@ -31,7 +31,8 @@ The following table lists the serialization formats currently supported by refle
 
 | Format       | Library                                              | Version      | License    | Remarks                                              |
 |--------------|------------------------------------------------------|--------------|------------| -----------------------------------------------------|
-| JSON         | [YYJSON](https://github.com/ibireme/yyjson)          | >= 0.8.0     | MIT        | out-of-the-box support, included in this repository  |
+| JSON         | [yyjson](https://github.com/ibireme/yyjson)          | >= 0.8.0     | MIT        | out-of-the-box support, included in this repository  |
+| BSON         | [libbson](https://github.com/mongodb/libbson)        | >= 1.25.1    | Apache 2.0 |                                                      |
 | flexbuffers  | [flatbuffers](https://github.com/google/flatbuffers) | >= 23.5.26   | Apache 2.0 |                                                      |
 | XML          | [pugixml](https://github.com/zeux/pugixml)           | >= 1.14      | MIT        |                                                      |
 | YAML         | [yaml-cpp](https://github.com/jbeder/yaml-cpp)       | >= 0.8.0     | MIT        |                                                      |
@@ -448,6 +449,7 @@ To use reflect-cpp in your project:
 ```cmake
 add_subdirectory(reflect-cpp) # Add this project as a subdirectory
 
+set(REFLECTCPP_BSON ON) # Optional
 set(REFLECTCPP_FLEXBUFFERS ON) # Optional
 set(REFLECTCPP_XML ON) # Optional
 set(REFLECTCPP_YAML ON) # Optional
@@ -494,7 +496,7 @@ git submodule update --init
 ./vcpkg/bootstrap-vcpkg.bat # Windows
 # You may be prompted to install additional dependencies.
 
-cmake -S . -B build -DREFLECTCPP_BUILD_TESTS=ON -DREFLECTCPP_FLEXBUFFERS=ON -DREFLECTCPP_XML=ON -DREFLECTCPP_YAML=ON -DCMAKE_BUILD_TYPE=Release
+cmake -S . -B build -DREFLECTCPP_BUILD_TESTS=ON -DREFLECTCPP_BSON=ON -DREFLECTCPP_FLEXBUFFERS=ON -DREFLECTCPP_XML=ON -DREFLECTCPP_YAML=ON -DCMAKE_BUILD_TYPE=Release
 cmake --build build -j 4 # gcc, clang
 cmake --build build --config Release -j 4 # MSVC
 ```

Diff for: docs/README.md

@@ -56,11 +56,13 @@
 
 5.1) [JSON](https://github.com/getml/reflect-cpp/blob/main/docs/json.md)
 
-5.2) [flexbuffers](https://github.com/getml/reflect-cpp/blob/main/docs/flexbuffers.md)
+5.2) [BSON](https://github.com/getml/reflect-cpp/blob/main/docs/bson.md)
 
-5.3) [XML](https://github.com/getml/reflect-cpp/blob/main/docs/xml.md)
+5.3) [flexbuffers](https://github.com/getml/reflect-cpp/blob/main/docs/flexbuffers.md)
 
-5.4) [YAML](https://github.com/getml/reflect-cpp/blob/main/docs/yaml.md)
+5.4) [XML](https://github.com/getml/reflect-cpp/blob/main/docs/xml.md)
+
+5.5) [YAML](https://github.com/getml/reflect-cpp/blob/main/docs/yaml.md)
 
 ## 6) Advanced topics
 

Diff for: docs/bson.md

@@ -0,0 +1,100 @@
+# BSON 
+
+For BSON support, you must also include the header `<rfl/bson.hpp>` and link to the libbson library (https://github.com/mongodb/libbson).
+
+Like the name implies, BSON is a JSON-like binary format. It is most notably used by MongoDB.
+
+## Reading and writing
+
+Suppose you have a struct like this:
+
+```cpp
+struct Person {
+    std::string first_name;
+    std::string last_name;
+    rfl::Timestamp<"%Y-%m-%d"> birthday;
+    std::vector<Person> children;
+};
+```
+
+A `person` can be turned into a bytes vector like this:
+
+```cpp
+const auto person = Person{...};
+const auto bytes = rfl::bson::write(person);
+```
+
+You can parse bytes like this:
+
+```cpp
+const rfl::Result<Person> result = rfl::bson::read<Person>(bytes);
+```
+
+## Loading and saving
+
+You can also load and save to disc using a very similar syntax:
+
+```cpp
+const rfl::Result<Person> result = rfl::bson::load<Person>("/path/to/file.bson");
+
+const auto person = Person{...};
+rfl::bson::save("/path/to/file.bson", person);
+```
+
+## Reading from and writing into streams
+
+You can also read from and write into any `std::istream` and `std::ostream` respectively.
+
+```cpp
+const rfl::Result<Person> result = rfl::bson::read<Person>(my_istream);
+
+const auto person = Person{...};
+rfl::bson::write(person, my_ostream);
+```
+
+Note that `std::cout` is also an ostream, so this works as well:
+
+```cpp
+rfl::bson::write(person, std::cout) << std::endl;
+```
+
+(Since BSON is a binary format, the readability of this will be limited, but it might be useful for debugging).
+
+## Custom constructors
+
+One of the great things about C++ is that it gives you control over
+when and how you code is compiled.
+
+For large and complex systems of structs, it is often a good idea to split up
+your code into smaller compilation units. You can do so using custom constructors.
+
+For the BSON format, these must be a static function on your struct or class called
+`from_bson` that take a `rfl::bson::Reader::InputVarType` as input and return
+the class or the class wrapped in `rfl::Result`.
+
+In your header file you can write something like this:
+
+```cpp
+struct Person {
+    rfl::Rename<"firstName", std::string> first_name;
+    rfl::Rename<"lastName", std::string> last_name;
+    rfl::Timestamp<"%Y-%m-%d"> birthday;
+
+    using InputVarType = typename rfl::bson::Reader::InputVarType;
+    static rfl::Result<Person> from_bson(const InputVarType& _obj);
+};
+```
+
+And in your source file, you implement `from_bson` as follows:
+
+```cpp
+rfl::Result<Person> Person::from_bson(const InputVarType& _obj) {
+    const auto from_nt = [](auto&& _nt) {
+        return rfl::from_named_tuple<Person>(std::move(_nt));
+    };
+    return rfl::bson::read<rfl::named_tuple_t<Person>>(_obj)
+        .transform(from_nt);
+}
+```
+
+This will force the compiler to only compile the BSON parsing when the source file is compiled.

Diff for: include/rfl/bson.hpp

@@ -0,0 +1,12 @@
+#ifndef RFL_BSON_HPP_
+#define RFL_BSON_HPP_
+
+#include "bson/Parser.hpp"
+#include "bson/Reader.hpp"
+#include "bson/Writer.hpp"
+#include "bson/load.hpp"
+#include "bson/read.hpp"
+#include "bson/save.hpp"
+#include "bson/write.hpp"
+
+#endif

Diff for: include/rfl/bson/Parser.hpp

@@ -0,0 +1,17 @@
+#ifndef RFL_BSON_PARSER_HPP_
+#define RFL_BSON_PARSER_HPP_
+
+#include "../parsing/Parser.hpp"
+#include "Reader.hpp"
+#include "Writer.hpp"
+
+namespace rfl {
+namespace bson {
+
+template <class T>
+using Parser = parsing::Parser<Reader, Writer, T>;
+
+}
+}  // namespace rfl
+
+#endif