[R6RS] Changing the transcoding mid-stream

[William D Clinger]

I have checked in two new files:

    srfi/io/port-io-alt.html
    srfi/io/performance.txt

The first of these amounts to a fairly major redesign
of the i/o system, less than 10 days before the first
public release of a draft of the R6RS.

The second is just a note to explain why I am not
worried about the efficiency of the redesign, and
am more confident of its efficiency than of the
design I hope it will replace.

Will