Ariles

branch	master	pkg_ros (ROS package)	pkg_freebsd (FreeBSD package)
CI status			X

Contents

• Links
• Introduction
  • Use cases
• Minimal example
  • APIv1
  • APIv2
• Supported formats
• Supported types
• Dependencies and compilation

Links

• Documentation (Doxygen): https://asherikov.github.io/ariles/1/
• GitHub: https://github.com/asherikov/ariles
• Travis CI: https://travis-ci.org/asherikov/ariles

Introduction

Note: this is a legacy branch, the main development branch is https://github.com/asherikov/ariles/tree/head_2

ariles is a C++ reflection library with focus on serialization/configuration. It relies on other open-source libraries for parsing and emission of data in different formats, in particular: YAML, JSON, XML, ROS parameter server. The library also provides some predefined serialization wrappers for common types, e.g., some standard containers and smart pointers.

Use cases

1. Parsing and generation of configuration files. Unlike some common serialization libraries, e.g., boost::serialization, ariles tries to be flexible while parsing by:

   • silently ignoring unused entries (if possible),
   • ignoring ordering of entries (if possible),
   • not discriminating attributes from childs in XML,
   • optionally ignoring missing entries.

2. Conversion between different formats, for example, YAML <-> ROS parameter server. Note that the conversion is not data-agnostic, i.e., the complete structure of the data must be represented in C++ code.

3. ariles facilitates collection of time-series data by flattening a class hierarchy to a list of name-value pairs (string-double).

4. ariles can emit Octave script code containing all data, which is useful for debugging of numerical software.

5. Due to flexibile parsing, ariles can be used to process generic file formats, e.g., URDF.

Minimal example

Currently ariles provides two API versions:

• APIv1: to be deprecated in the next major release,
• APIv2: new, unstable API.

APIv1

Demo: https://asherikov.github.io/ariles/1/DEMOv1.html [./tests/api_v1/demo_api_v1.cpp]

Class [./tests/api_v1/types/minimal.h]:

class Configurable : public ariles::ConfigurableBase
{
    #define ARILES_SECTION_ID "ConfigurableEntryName"
    #define ARILES_AUTO_DEFAULTS
    #define ARILES_ENTRIES \
        ARILES_TYPED_ENTRY(integer_member, int)
    #include ARILES_INITIALIZE
};

Serialization:

Configurable configurable;
configurable.writeConfig<ariles::yaml_cpp>("config_file.yaml");
configurable.writeConfig<ariles::yaml_cpp>(std::cout);

Result:

ConfigurableEntryName:
    integer_member: 0

Deserialization:

configurable.readConfig<ariles::yaml_cpp>("config_file.yaml");

Conversion:

configurable.readConfig<ariles::yaml_cpp>("config_file.yaml");
configurable.writeConfig<ariles::ros>(nh, "/some_namespace/");

APIv2

Demo: https://asherikov.github.io/ariles/1/DEMOv2.html [./tests/api_v2/demo_api_v2.cpp]

Class [./tests/api_v2/types/minimal.h]:

class Configurable : public ariles::DefaultBase
{
    #define ARILES_ENTRIES \
        ARILES_TYPED_ENTRY(integer_member, int)
    #include ARILES_INITIALIZE
};

Serialization:

Configurable configurable;
ariles::apply<ariles::yaml_cpp::Writer>("config.yaml", configurable);
ariles::apply<ariles::yaml_cpp::Writer>(std::cout, configurable);

Result:

ConfigurableEntryName:
    integer_member: 0

Deserialization:

ariles::apply<ariles::yaml_cpp::Reader>("config.yaml", configurable);

Conversion:

ariles::apply<ariles::yaml_cpp::Reader>("config.yaml", configurable);
ariles::apply<ariles::ros::Writer>(nh, configurable, "/some_namespace/");

Supported data formats

Currently supported formats are (all are optional):

• YAML via yaml-cpp, both old C++03 and new API supported.

  • yaml-cpp does not comply with the specification when it emits NaN's and infinities, see jbeder/yaml-cpp#507. ariles includes a workaround for this issue.

• msgpack via msgpack-c.

• JSON via RapidJSON, with optional Jsonnet (https://jsonnet.org/) preprocessing:

  • NaN's and infinities, which are not allowed by JSON specification, are optionally parsed / emitted using boost::lexical_cast.

• XML via PugiXML:

  • Attributes are treated as childs while parsing and are never used for emission.

• Octave script, output only, no dependencies:

  • Eigen matrices are written in the 'native' format, so they can be used directly, no reshaping is necessary.

  • Matlab might be supported, but has not been tested.

• ROS parameter server, via standard ROS libs.

• A set of key-value pairs, output only, no dependencies:

  • A vector of string-double pairs with flattened member names, e.g., <class.member_class.member, value>.

Supported data types

• Fundametal types: signed/unsigned integers, floats, booleans.
• Some STL classes (WIP): std::string, std::vector, std::map, std::pair, std::shared_ptr, std::unique_ptr.
• Eigen types: matrices, transforms, quaternions.
• Boost classes: boost::optional, boost::movelib::unique_ptr. boost::shared_ptr.
• Better enums -> https://github.com/aantron/better-enums.

Dependencies and compilation

Dependencies

ariles does not depend on new C++ features and is C++03 compliant.

Support of any data format, and corresponding dependency, can be enabled or disabled via cmake options. The same applies to data types which depend on external libraries. The only mandatory requirement is Boost.

Compilation with catkin

An example catkin package is provided in pkg_ros branch of the main repository -> https://github.com/asherikov/ariles/tree/pkg_ros.