Stream (abstract data type)

In type theory and functional programming, a stream is a potentially infinite analog of a list, given by the coinductive definition:

data Stream α = Nil | Cons α (Stream α)

Generating and computing with streams requires lazy evaluation, either implicitly in a lazily evaluated language or by creating and forcing thunks in an eager language. In total languages they must be defined as codata and can be iterated over using (guarded) corecursion.

Java provides the

JavaScript provides theReadableStream,WritableStream andTransformStream interfaces.

Python have theStreamReader andStreamWriter classes in theasyncio module.

.NET provides the abstract classStream which is implemented by classes such asFileStream andMemoryStream.

In Rust a struct can implement theRead trait. There is also theCursor struct wraps an in-memory buffer.

• Coinduction