[r6rs-discuss] [Formal] string output ports

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Submitter: William D Clinger
Email address: will_at_ccs.neu.edu
Issue type: Defect
Priority: Minor
Component: I/O
Report version: 5.92
Summary: String output ports are even more broken now.
Hidden amongst all the welcome changes to the i/o system
were some less welcome changes to string output ports.
First of all, the open-string-output-port procedure still
requires a useless proc argument.
More importantly, the string ports of version 5.91 were
compatible with the string ports of SRFI 6 in the sense
that either could be implemented in terms of the other
with little effort.  The string output ports of version
5.92 are no longer compatible with SRFI 6, because there
is no way to implement the get-output-string procedure
of SRFI 6 using operations of version 5.92.
No rationale for this change has been offered, and the
editors' email discussions (which, SFAIK, are not yet
public, else I would cite the thread that somehow led
to this change) contain no serious argument for it.
I recommend that the operations on string output ports
revert to their specification in version 5.91, modulo
corrections, removal of optional transcoder arguments,
and any other changes that may have been made necessary
by improvements to the rest of the i/o system.  The
editors' Subversion repository contains a proposal
along these lines, and the editors' email archive
contains a correction to that proposal.
Will