A replacement for the Open Dylan <sequence-stream> classes.

This module is motivated by various issues with <sequence-stream> in Open Dylan's IO library. It provides implementations for stream methods that act as described in the Open Dylan Streams Module documentation.

If possible, these classes use the contents: initialization argument as the backing store; if not, they use a copy. The backing store will be a general instance of <vector> and will be a <stretchy-vector> if and only if the stream is writable. This differs from the normal <sequence-stream> class, in which using a <stretchy-vector> as the contents: initialization argument guarantees that all changes to the <stretchy-vector> are reflected in the <sequence-stream> and vice versa.

When a writable <sequence-stream> grows its backing store, it uses the filler element specified by the fill: initialization argument.

This class supports a position-offset: initialization argument that sets the effective stream position at the first element of the stream. This allows sequence streams to act as a subset of another, larger stream. The initialization argument defaults to 0.