GNU Smalltalk User's Guide
4.10 Smalltalk Streams
Our examples have used a mechanism extensively, even
though we haven't discussed it yet. The Stream class provides
a framework for a number of data structures, including
input and output functionality, queues, and endless sources
of dynamically-generated data. A Smalltalk stream is quite
similar to the UNIX streams you've used from C. A stream
provides a sequential view to an underlying resource; as you
read or write elements, the stream position advances until
you finally reach the end of the underlying medium. Most
streams also allow you to set the current position, providing
random access to the medium.