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Channel Types

How are channels mapped?

How to define a new channel type

  1. In a repository of your choice (or start with harnice_library_public on your own branch), navigate to library_repo/channel_types/channel_types.csv
  2. If you want channel definitions to be private and are therefore working in a private repository, ensure the repo's path is listed in file library_locations.csv (located at root of your harnice source code repo). The first column is the URL or traceable path, and the second column is your local path.
  3. If you find the channel_type you're looking for, temporarily note it as a touple in a notepad somewhere with format (ch_type_id, universal_library_repository).
  4. If you don't find it, make a new one. It's important to try and reduce the number of channel_types in here to reduce complexity, but it's also important that you adhere to strict and true rules about what is allowed to be mapped to what. Modifications and additions to this document should be taken and reviewed very seriously.
chtype.path(channel_type)

Resolve the on-disk path to the channel_types.tsv file for a given channel type.

Args

  • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand (for example "(5, 'https://github.com/harnice/harnice')").

Returns

  • str: Absolute path to the channel_types/channel_types.tsv file inside the library repository that owns the given channel type.

Notes

  • This does not filter rows; it only locates the TSV file that defines all channel types for the given lib_repo.
chtype.parse(val)

Convert stored string into a tuple (chid:int, lib_repo:str). Handles both single tuples and extracts first tuple from lists.

chtype.compatibles(channel_type)

Look up other channel types that are declared as compatible with the given channel type.

Args

  • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand.

Returns

  • list[tuple[int, str]]: List of (channel_type_id, lib_repo) tuples taken directly from the compatible_channel_types column of channel_types.tsv. Returns an empty list if no compatibles are defined or if the channel type cannot be found.

Data format

  • The compatible_channel_types column must be an AST-parseable Python value:
    • Single tuple: (1, "library_repo")
    • List of tuples: [(1, "library_repo"), (2, "library_repo")]
chtype.attribute(channel_type, attribute)

Read any additional column from channel_types.tsv for a given channel type.

Args

  • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand.
  • attribute: Column header name in channel_types.tsv for the value you want to read (for example "description", "notes", "voltage_rating").

Returns

  • Any: Value stored in the requested attribute column for the matching channel_type_id. Returns an empty list [] if the channel type cannot be found.

Notes

  • Use this for any per-channel-type metadata you've added as extra columns beyond the core ones like channel_type_id, signals, and compatible_channel_types.
chtype.signals(channel_type)

Return the list of signal names associated with a specific channel type.

Args

  • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand.

Returns

  • list[str]: List of signal names from the signals column of channel_types.tsv for the matching channel_type_id. If the column is blank or the channel type cannot be found, returns an empty list.

Data format

  • The signals column is expected to be a comma-separated string, for example: "CAN_H, CAN_L, SHIELD".
chtype.is_or_is_compatible_with(channel_type)

Return the given channel type plus all channel types declared as compatible with it.

Args

  • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand.

Returns

  • list[tuple[int, str]]: List of (channel_type_id, lib_repo) tuples where the first entry is the parsed channel_type itself and the remaining entries are the compatibles returned by compatibles(channel_type).

Typical use

  • Use this when validating or mapping channels and you want to treat a channel type as valid if it is either exactly the requested type or explicitly listed as compatible with it.