Pamoja.Ros2 0.2.0

Pamoja.Ros2

ROS 2 names, RIHS01 type hashes, CDR encoding, and rmw_zenoh key assembly, with no ROS 2 installed. One capability of pamoja, one memory-safe Rust core with bindings for TypeScript, Python, and C#.

Install

dotnet add package Pamoja.Ros2

using Pamoja.Ros2;

This pulls in Pamoja.Native, the compiled engine. dotnet add package Pamoja is the whole framework in one package.

Example

The guide project's example, spliced here as it ran in CI.

From bindings/dotnet/samples/Pamoja.Guides/Ros2Guide.cs:

// A name is slash-separated tokens of letters, digits, and underscores. A token may
// not start with a digit, and a name may not end in a slash, hold an empty token, or
// double an underscore.
const string camera = "/robot1/camera_left/image_raw";
if (Ros2.IsValidName(camera))
{
    Console.WriteLine($"valid     {camera}");
}

foreach ((string name, string why) in new[]
{
    ("/2foo", "a token starts with a digit"),
    ("/cmd_vel/", "it ends in a slash"),
    ("/robot1//odom", "it has an empty token"),
    ("/robot1/cmd__vel", "it doubles an underscore"),
})
{
    if (!Ros2.IsValidName(name))
    {
        Console.WriteLine($"invalid   {name}, since {why}");
    }
}

// A name with no leading slash is relative, and one that starts with a tilde is
// private. Both are valid, and both resolve against the node before they reach the
// wire, so neither is fully qualified.
foreach ((string label, string name, string against) in new[]
{
    ("relative", "cmd_vel", "the node's namespace"),
    ("private", "~/setpoint", "the node's own name"),
})
{
    if (Ros2.IsValidName(name) && !Ros2.IsFullyQualified(name))
    {
        Console.WriteLine($"{label,-10}{name} is valid, and resolves against {against} first");
    }
}

// Only a fully qualified name reaches the wire. DDS puts a prefix before it that says
// what kind of endpoint it is, and a service travels on two topics, each ending in the
// suffix the middleware appends.
string? published = Ros2.DdsTopic("/robot1/cmd_vel", EntityKind.Topic);
string? asked = Ros2.DdsTopic("/robot1/add_two_ints", EntityKind.ServiceRequest);
string? answered = Ros2.DdsTopic("/robot1/add_two_ints", EntityKind.ServiceResponse);
Console.WriteLine($"topic     /robot1/cmd_vel travels on {published}");
Console.WriteLine($"request   /robot1/add_two_ints asks on {asked}");
Console.WriteLine($"reply     and answers on {answered}");

// A message type maps to a DDS type name the same way, so both ends agree on what is
// carried before a byte is exchanged. A name that is not package/namespace/Type maps
// to nothing rather than to something plausible.
foreach (string rosType in new[]
{
    "std_msgs/msg/String",
    "example_interfaces/srv/AddTwoInts",
    "std_msgs/String",
})
{
    Console.WriteLine(Ros2.DdsTypeName(rosType) is { } carried
        ? $"type      {rosType} is named {carried}"
        : $"malformed {rosType} is not package/namespace/Type, so it has no DDS type name");
}

The same capability in every language

Documentation

• Pamoja.Ros2 reference, every type in this namespace.
• The ROS 2 rules guide, with the same example in Rust, TypeScript, and Python.
• Every capability, and the install page.

License

MIT