@lichtblick/rosmsg

> _ROS1 and ROS2 message definition parser_


Introduction

The Robot Operating System (ROS) defines a simplified message description language for describing data types. This library parses those message definitions and can round trip them back into a canonical string format suitable for checksum generation. The parsed definitions are useful for serialization or deserialization when paired with other libraries.

This library supports both ROS1 and ROS 2 message definitions.

ROS 1 Definition Usage

``Typescript
import { parse, stringify } from "@lichtblick/rosmsg";

const definitionStr = # geometry_msgs/Pose
geometry_msgs/Point position
geometry_msgs/Quaternion orientation

===
MSG: geometry_msgs/Point
float64 x
float64 y
float64 z

===
MSG: geometry_msgs/Quaternion
float64 x
float64 y
float64 z
float64 w;

const messageDefinition = parse(definitionStr);

// print the parsed message definition structure
console.log(JSON.stringify(messageDefinition, null, 2));
`

Prints:

`JSON
[
{
"definitions": [
{
"type": "geometry_msgs/Point",
"isArray": false,
"name": "position",
"isComplex": true
},
{
"type": "geometry_msgs/Quaternion",
"isArray": false,
"name": "orientation",
"isComplex": true
}
]
},
{
"name": "geometry_msgs/Point",
"definitions": [
{
"type": "float64",
"isArray": false,
"name": "x",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "y",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "z",
"isComplex": false
}
]
},
{
"name": "geometry_msgs/Quaternion",
"definitions": [
{
"type": "float64",
"isArray": false,
"name": "x",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "y",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "z",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "w",
"isComplex": false
}
]
}
]
`

ROS 2 Definition Usage

`Typescript
import { parse, stringify } from "@lichtblick/rosmsg";

const definitionStr = # geometry_msgs/msg/Pose
geometry_msgs/msg/Point position
geometry_msgs/msg/Quaternion orientation

===
MSG: geometry_msgs/msg/Point
float64 x
float64 y
float64 z

===
MSG: geometry_msgs/msg/Quaternion
float64 x
float64 y
float64 z
float64 w;

const messageDefinition = parse(definitionStr, {ros2: true});

// stringify(messageDefinition) will return a canonical string, similar to
// _definitionStr_
// print the parsed message definition structure
console.log(JSON.stringify(messageDefinition, null, 2));
`

Prints:

`JSON
[
{
"definitions": [
{
"type": "geometry_msgs/msg/Point",
"isArray": false,
"name": "position",
"isComplex": true
},
{
"type": "geometry_msgs/msg/Quaternion",
"isArray": false,
"name": "orientation",
"isComplex": true
}
]
},
{
"name": "geometry_msgs/msg/Point",
"definitions": [
{
"type": "float64",
"isArray": false,
"name": "x",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "y",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "z",
"isComplex": false
}
]
},
{
"name": "geometry_msgs/msg/Quaternion",
"definitions": [
{
"type": "float64",
"isArray": false,
"name": "x",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "y",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "z",
"isComplex": false
},
{
"type": "float64",
"isArray": false,
"name": "w",
"isComplex": false
}
]
}
]
`

ROS 2 IDL Support

See (@lichtblick/ros2idl-parser)[https://github.com/lichtblick-suite/omgidl/packages/ros2idl-parser] for our implementation of ros2idl schema support.

License

@lichtblick/rosmsg is licensed under the MIT License.

Releasing

1. Run yarn version --[major|minor|patch] to bump version
2. Run git push && git push --tags` to push new tag
3. GitHub Actions will take care of the rest