This SRFI defines an I/O layer for lazy, mostly functional buffered streams.

The layer architecture is similar to the upper three layers of the I/O subsystem in The Standard ML Basis Library.

In particular, this layer provides

• buffered reading and writing
• arbitrary lookahead
• dynamic redirection of input or output
• binary and text I/O, mixed if needed
• translated data streams
• the ability to create I/O streams from arbitrary readers and writers

It builds on the Primitive I/O layer specified in SRFI 79 (Primitive I/O).