SequenceBinding

SequenceBinding is a software pattern and, in some libraries, a formal abstraction for linking the elements of two or more sequences so that changes in one sequence are reflected in the others. It is used to synchronize collections, streams, or sequences of events, ensuring consistent state without manual iteration or ad hoc updates.

A binding defines a mapping between source and target sequences. Bindings may be one-to-one, where the i-th element of the source corresponds to the i-th element of the target; one-to-many bindings can duplicate source elements to multiple targets; and filtered or transformed bindings apply a function to produce target values. Bindings can be unidirectional or bidirectional, with optional conflict resolution rules for simultaneous updates. Implementations often support lifecycle controls, such as subscribing and unsubscribing, and may provide options for ordering, gap handling, and change batching.

In practice, SequenceBinding is used in user interfaces to keep a displayed list in sync with a data source, in data processing pipelines to propagate updates through stages, and in sensor or event streams to align timing and content. Binding configurations may specify transformation functions, synchronization intervals, and constraints to preserve invariants across the linked sequences.

Relation to other concepts: SequenceBinding is a form of data binding and shares goals with reactive programming, streams, and observer patterns. Unlike simple event notifications, SequenceBinding emphasizes sequence-level synchronization, ordering, and transformation across multiple sequences.

History and usage notes: The concept derives from data-binding and reactive programming trends in modern software development, where libraries provide abstractions to manage complex, stateful synchronization between sequences with predictable semantics.