Protocols

This module provides various protocols used throughout the package.

A typing.Protocol is an interface that a class can fulfill structurally, without explicitly inheriting from it. For example, any class that implements a __len__ method satisfies Sized, whether or not it says so anywhere in its class hierarchy.

The protocols in this module follow the same idea, but each one centers on a single, otherwise unremarkable dunder-style method (for example _linear_operator_). A class implementing that one method thereby satisfies the corresponding protocol – SupportsLinearOperator in this example – and becomes usable wherever that protocol is expected, without any explicit registration. Note that “protocol” is sometimes also used loosely to refer to the type-agnostic dispatch function built on top of a protocol (for example linear_operator()) rather than the interface itself; the distinction should be clear from context.

Most protocols below follow this pattern paired with a small, type-agnostic helper function that dispatches to the protocol method on whatever object it is given: