ev3dev Language Wrapper SpecificationΒΆ

This is an unofficial specification that defines a unified interface for language wrappers to expose the ev3dev device APIs.

General Notes

Because this specification is meant to be implemented in multiple languages, the specific naming conventions of properties, methods and classes are not defined here. Depending on the language, names will be slightly different (ex. “touchSensor” or “TouchSensor” or “touch-sensor”) so that they fit the language’s naming conventions.

Some concepts that apply to multiple classes are described as “abstracts”. These abstract sections explain how the class should handle specific situations, and do not necessarily translate in to their own class in the wrapper.

Implementation Notes (important)

  • File access. There should be one class that is used or inherited from in all other classes that need to access object properties via file I/O. This class should check paths for validity, do basic error checking, and generally implement as much of the core I/O functionality as possible.
  • Errors. All file access and other error-prone calls should be wrapped with error handling. If an error thrown by an external call is fatal, the wrapper should throw an error for the caller that states the error and gives some insight in to what actually happened.
  • Naming conventions. All names should follow the language’s naming conventions. Keep the names consistent, so that users can easily find what they want.
  • Attribute types. int and string attributes are read-write files containing a single value that is representable either as an integer or as a single word. A string array attribute is a readonly file that contains space-separated list of words, where each word is a possible value of some other string atribute. And a string selector attribute is a read-write file that contains space-separated list of possible values, where the currently selected value is enclosed in square brackets. Another value may be selected by writing a single word to the file.


Compatibility table

Spec Version Fully Supported Kernel Version
v0.9.1 v3.16.1-7-ev3dev
v0.9.2 v3.16.7-ckt10-4-ev3dev
v1.0.0 v3.16.7-ckt21-9-ev3dev