Signal Mapping Definition Machine

This document is in progress

The model definition machine utilizes method cascading with an entry point at zmbt::api::SignalMapping class, which consumes a model name.

Each subsequent method call consumes some parameter and transitions to a subclass of zmbt::mapping::ModelDefinition that narrows the choices to methods valid for that specific step, effectively forming a push-down automaton. This technique simplifies the API usage, enhancing the code completion and checking certain errors at compilation stage.

Each model is resolved and tested on reaching it's destructor.

The railroad diagram below shows the incomplete BNF definition of the Signal Mapping DSL. Omitted rules may be deduced from introduction given above or from the following documentation.

Channel clauses

Each channel node of the model definition starts with InjectTo or ObserveOn method, followed with optional filters. Each filter has one or more mutually exclusive clauses.

The channel definition node is terminated once the new channel started with the InjectTo or ObserveOn method, or when the definition switches to Parameters or Tests nodes.

Channel filters:

• Role:
  • InjectTo: start stimulus definition on a specified interface.
  • ObserveOn: start response observation definition on a specified interface.
  • interface referencing syntax and defaults are the same as for InterfaceRecord with one exception: refobj resolves as trigger object if compatible mfp provided.
• Kind:
  • Return: address the interface return value by a signal path (JSON Pointer).
    • default (no args): "/".
  • Args: address the interface arguments tuple by a signal path (JSON Pointer).
    • default (no args): "/0" for unary interfaces, "/" otherwise (follows the Boost JSON logic).
  • CallCount: address the number of observed interface calls (used for mocks).
  • Exception: address the interface thrown or observed exceptions.
  • default kind (when none of the above are specified):
    • if on trigger: Args for InjectTo, Return for ObserveOn.
    • if on mock: Args for ObserveOn, Return for InjectTo.
• Other:
  • As: specify the type decorator for channel signal (see zmbt::SignalOperatorHandler).
    • default: zmbt::GenericSignalOperator, good enough for most cases.
  • Call: specify the interface call number (0-based).
    • Negative value is resolved as a reverse index, with -1 referring to the last call.
    • default: -1
  • CallRange: specify the interface call range in 0-based slice with inclusive boundaries.

Interface referencing

WIP