chronaxis.extensions.FunctionSpec

from chronaxis.extensions import FunctionSpec

`FunctionSpec`

Declare a stateless pointwise function. impl(args, resources) returns ScalarValue or NumericArray with the matching shape.

python

FunctionSpec(name: str, version: str, inputs: tuple[chronaxis.extensions.ValueSpec, ...], output: chronaxis.extensions.ValueSpec, reference: object = None, numpy: object = None) -> None

Name	Type	Required	Default	Purpose
`name`	str	Yes	No default	Expression identifier, unique in the registry and distinct from built-in operations.
`version`	str	Yes	No default	Nonempty implementation version; the host must change it when implementation behavior changes.
`inputs`	tuple[chronaxis.extensions.ValueSpec, ...]	Yes	No default	Nonempty tuple of ValueSpec ports in positional argument order. BOOL uses unit 1; extract enum codes before calling.
`output`	chronaxis.extensions.ValueSpec	Yes	No default	Output ValueSpec port declaring the callback result dtype and unit.
`reference`	object	No	None	Point implementation `impl(args, resources)`. args is a tuple of ScalarValue objects in inputs order; return one ScalarValue matching output. resources reserves/releases temporary memory. None disables this backend; provide at least one backend, with no automatic fallback.
`numpy`	object	No	None	Array point implementation `impl(args, resources)`. args is a tuple of NumericArray objects in inputs order; return a NumericArray of matching length and output type. Only rows with all required inputs valid are passed. None disables numpy; reference is not substituted.

Returns

Immutable FunctionSpec declaration.

Raises

Invalid names, ports, versions, or implementations reject construction with ValueError or TypeError and a specific reason.

Execution and resources

Invalid required inputs propagate invalidity; an unselected where branch is not executed. Registration checks declarations without calling the implementation.

Declare ports with from chronaxis.extensions import ValueSpec and from chronaxis.core.types import SignalDType. For example, ValueSpec(SignalDType.FLOAT64, "A") declares a numeric current port.

`require_backend`

python

FunctionSpec.require_backend(backend)

Inherited method: backend is required and must be reference or numpy. Returns that registered callback/factory; raises ValueError for an unknown or unsupported backend.

Worked host example

Source: src/chronaxis/extensions.py:73 (line at 8904c2f744951857659abd40aaa3535d57faf53c).