it returns.

code/extfmts.lisp:
* Move the utf-8 implementation to this file
* Update %find-external-format to return quickly for :utf-8. 

code/fd-stream-comp.lisp:
* Precompile utf-8 functions.

pcl/simple-streams/external-formats/utf-8.lisp:
* Add note that this is only used for reference now because it's in
  the core.

the number of characters converted when a buffer is given.  If the
buffer is not large enough, not all characters are converted.  This is
an incompatible change from the previous version.

Suggested by Helmut Eller, cmucl-imp, 2011-10-29.

entries with just the file path, removing the revision number, date,
author and state.  The actual information is now computed during
compilation and stored in the fasl itself.  (See ticket:48.)

  Foley.)
o While we're here, canonicalize *FILENAME-ENCODING* using the actual
  external format name.

happens.

the octets consumed for each character.  This array is used to figure
out the file position.  Some tests comparing this scheme indicates a
very small slowdown of about 1%, so this seems not to hurt.

Use a cross-compile using the 2010-07 snapshot to build this.  (Same
procedure as used to build the 20b-pre1 release.)

struct.lisp:
o Add new slot OCTET-COUNT to LISP-STREAM to hold the array of octets
  per character.

extfmts.lisp:
o Add OCTETS-TO-STRING-COUNTED, which is like OCTETS-TO-STRING, except
  we need an array in which to store the number of octets consumed for
  each character processed.

fd-stream.lisp:
o Create the octet-count array creating the lisp stream string buffer.
o In FD-STREAM-FILE-POSITION, use the octet count to count the number
  of octets that have been read but not yet returned to the user.

stream.lisp:
o Use OCTETS-TO-STRING-COUNTED instead of OCTETS-TO-STRING so we keep
  track of octet length of each character processed.

ascii.lisp:
iso8859-1.lisp:
iso8859-2.lisp:
mac-roman.lisp:
utf-16.lisp:
utf-32-be.lisp:
utf-32-le.lisp:
utf-32.lisp:
utf-8.lisp:
o Inhibit warnings about funcalls to error (fdefinition of symbols).
  I'm tired of seeing the warnings.

utf-16-be.lisp:
utf-16-le.lisp:
o Inhibit warnings about funcalls to error (fdefinition of symbols).
  I'm tired of seeing the warnings.
o Fix bug in FLUSH-STATE:  need to call the OUT function, not the
  ,OUTPUT function!

compiler noise for something we don't really care if it's slow.

little information about the format.  Provide a means to get a list of
external formats and to display the documentation.

bootfiles/20a/boot-2010-07-1.lisp:
o Use this bootstrap file when doing a normal build.

code/exports.lisp:
o New functions:
  - Add LIST-ALL-EXTERNAL-FORMATS to list all available external formats
    and their corresponding aliases.
  - Add DESCRIBE-EXTERNAL-FORMAT to print some information about the
    given format.
o Add docuemntation slot to defstruct EXTERNAL-FORMAT.
o Change DEFINE-EXTERNAL-FORMAT macro.  Adds :DOCUMENTATION keyword to
  specify the documentation.  Add :BASE keyword indicate that the
  external format is based on another format.  (Previously, this
  wasn't needed, but is somewhat incompatible with adding a
  documentation string.)
o Change DEFINE-COMPOSING-EXTERNAL-FORMAT to include :documentation
  keyword to specify the documentation for the format.
o Minor reindentation of some docstrings.
o Make sure documentation strings for external format are marked for
  translation; wrap other strings with intl:gettext to explicitly mark
  them for translations.
o Add docstring for VOID and ISO8859-1 external formats.

code/exports.lisp:
o Export the new symbols LIST-ALL-EXTERNAL-FORMATS and
  DESCRIBE-EXTERNAL-FORMAT.  Import into EXTENSIONS package.

docs/cmu-user/unicode.tex:
o Update docs to include LIST-ALL-EXTERNAL-FORMATS and
  DESCRIBE-EXTERNAL-FORMAT.
o Update docs for DEFINE-EXTERNAL-FORMAT and
  DEFINE-COMPOSING-EXTERNAL-FORMAT to match implementation.

general-info/release-20b.txt:
o Update

external-formats/*.lisp:
o Update with docstrings.
o Add :BASE keyword where needed.

o Add a simple function it list all external formats.
o Add some docstrings.
o Correctly indent some s-exps.

exports.lisp:
o Update package definitions to export new LIST-ALL-EXTERNAL-FORMATS.

  args.
o Generate different error messages for surrogate code points and code
  points that are too large.

o Revert previous incompatible change to STRING-DECODE and
  STRING-ENCODE.  Change the keyword parameters back to optional
  parameters, and make the error parameter the last one.

fd-stream.lisp:
o Update use of STRING-ENCODE.

o Update comments for the various slots in DEFINE-EXTERNAL-FORMAT.

fd-stream.lisp:
o Declare the types for the CHAR-TO-OCTETS-ERROR and
  OCTETS-TO-CHAR-ERROR slots in FD-STREAM.
o Update docstrings for MAKE-FD-STREAM and OPEN for :DECODING-ERROR
  and :ENCODING-ERROR parameters.

o Add error parameter to flush-state in external format definition so
  we can handle errors when flushing the state to a stream.
o Add optional error parameter to flush-state macro.

code/fd-stream.lisp:
o For the case where an external format has flush method, EF-FLUSH was
  not calling it correctly.  Update so the output function actuall
  works.
o Add error handler to call to flush-state.
o For the case where an external format does not have a flush method,
  output the state value instead of a replacement character so the
  external format can handle any errors.

o Pass the error handler on for composed external formats.

code/fd-stream.lisp:
o Forgot to pass the error-handler to char-to-octets in EF-COUT.
o In MAKE-FD-STREAM slightly change handling of encoding-error and
  decoding-error:
  - If :encoding-error is a character, then the external format will
    use that character whenever an encoding error happens instead of
    the default (internally specified by the external format).
  - If :decoding-error is a character, then the external format will
    use that character whenever an encoding error happens instead of
    the default (internally specified by the external format).  If
    :decoding-error is T, then a cerror is signaled; if continued, the
    Unicode replacement character (#\U+FFFD) is used.
o Fix bug in OPEN:  The :decoding-error and :encoding-error keyword
  parameter was placed in the &aux section by mistake.

o The optional error parameter doesn't need to be optional in
  DEFINE-EXTERNAL-FORMAT, EF-STRING-TO-OCTETS, EF-OCTETS-TO-STRING,
  EF-ENCODE and EF-DECODE.

code/fd-stream.lisp:
o Update comments for char-to-octets-error and octets-to-char-error.
o Forgot to pass the error handler to char-to-octets in EF-SOUT and
  EF-STRLEN.

code/extfmts.lisp
o Call the error handler for iso8859-1 output.
o In OCTETS-TO-CODEPOINT and CODEPOINT-TO-OCTETS, call the external
  format with the error argument.
o In OCTETS-TO-CHAR
  - Call OCTETS-TO-CODEPOINT with the error handler.
  - For all of the error conditions, call the error handler if
    defined.
o Add error parameter to EF-STRING-TO-OCTETS and EF-ENCODE so we can
  handle errors.  Call CHAR-TO-OCTETS with the error handler.
o Add error parameter to STRING-TO-OCTETS and use it.
o Add error parameter to EF-OCTETS-TO-STRING and EF-DECODE so we can
  handle errors.  Call OCTETS-TO-CHAR with the error handler.
o Add error parameter to OCTETS-TO-STRING and use it.
o In STRING-ENCODE and STRING-DECODE, call the ef function with the
  error handler.
o Change STRING-ENCODE to use keyword args instead of optional args.
  Add error parameter and use it.

code/fd-stream-extfmt.lisp:
o Tell OCTETS-TO-STRING about the error handler stored in the
  fd-stream.

code/fd-stream.lisp:
o OPEN, MAKE-FD-STREAM, and OPEN-FD-STREAM get DECODING-ERROR and
  ENCODING-ERROR keyword arguments for specifying how to handle
  decoding and encoding errors in external formats.

code/stream.lisp:
o Make sure the error handler is called in
  FAST-READ-CHAR-STRING-REFILL.

pcl/simple-streams/external-formats/utf-8.lisp:
o Initial cut at calling the error handler for the various possible
  invalid octet streams for a utf-8 encoding.

o All external formats need an extra required argument for the error
  handler.
o Add optional error parameter to OCTETS-TO-CODEPOINT,
  CODEPOINT-TO-OCTETS, OCTETS-TO-CHAR, and CHAR-TO-OCTETS.

may get confused with source locations if the reader macros are
installed.

boot-2010-02-1 as the bootstrap file.  You should probably also use
the new -P option for build.sh to generate and update the po files
while building.

ensure that we can compile the external format correctly no matter
what the user might have done to readtable and other variables.  This
supersedes the previous change that just bound *readtable* to the
standard read table.

format in case the user has set a non-standard readtable that can't
process the external format.

faster reads on external-formats.  This is done by adding an
additional buffer to streams so we can convert the entire in-buffer
into characters all at once.

To build this change, you need to do a cross-compile using
boot-2009-10-1-cross.lisp.  Using that build, do a normal build with
these sources.

For a non-unicode build use boot-2009-10-01.lisp with a 20a
non-unicode build.

code/extfmts.lisp:
o Add another slot to the extfmts for copying the state.
o Modify EF-OCTETS-TO-STRING and OCTETS-TO-STRING to support the
  necesssary changes for fast formats.  This is incompatible with the
  previous version because the string is not grown if needed.

code/fd-stream-extfmt.lisp:
o Set *enable-stream-buffer-p* to T so we have fast streams.

code/fd-stream.lisp:
o Add new slots to support fast strams.
o In SET-ROUTINES, initialize the new slots appropriately.
o Update UNREAD-CHAR to be able to back up in the string buffer to
  unread.
o Add implementation to copy the state of an external format.

code/stream.lisp:
o Change %SET-FD-STREAM-EXTERNAL-FORMAT to be able to change formats
  even if we've already converted the buffer with a different format.
  We reconvert the buffer with the old format until we reach the
  current character.  Then the remaining octets are converted using
  the new format and stored in the string buffer.
o Add FAST-READ-CHAR-STRING-REFILL to refill the string buffer, like
  FAST-READ-CHAR-REFILL does for the octet in-buffer.

code/struct.lisp:
o Add new slots to hold the string buffer, the current index, and
  length.  These are needed for the fast formats.

code/sysmacs.lisp:
o Update PREPARE-FOR-FAST-READ-CHAR, DONE-WITH-FAST-READ-CHAR, and
  FAST-READ-CHAR to support the string buffer.

code/string.lisp:
o Microoptimization of SURROGATEP to reduce the number of branchs.

general-info/release-20b.txt:
o Update with these changes

pcl/simple-streams/external-formats/utf-16-be.lisp:
pcl/simple-streams/external-formats/utf-16-le.lisp:
pcl/simple-streams/external-formats/utf-16.lisp:
o These formats actually have state, so update them to take a handle
  an initial state.  These are needed if the string buffer ends with a
  leading surrogate and the next string buffer starts with a trailing
  surrogate.  The conversion needs to combine the surrogates together.

closing an output stream.  This causes things like

(with-open-file (s "foo" :direction :output :external-format :utf-8)
  (write-char #\u+d800 s))

to output the replacement character instead of creating an empty file.

code/extfmts.lisp:
o Add new slot to efx structure to hold the function to flush the
  state in an external format.
o Add accessor for the flush-state slot.
o Update DEFINE-EXTERNAL-FORMAT to allow specifying the flush
  function.
o Add macro to call the flush-state function.
o Added +EF-FLUSH+
o Use vm::defenum to name the constants instead of the hand-written
  values.
o Export +REPLACEMENT-CHARACTER-CODE+
o Document the slots in an efx stucture.

code/fd-stream.lisp:
o Add ef-flush def-ef-macro to flush the state of an external format
  when closing an output file.  If ef-flush-state is NIL, we just call
  EF-COUT to send out the replacement character.  Otherwise, the
  flush-state function is called to handle it.
o When closing an output character stream, call ef-flush to flush any
  state before flushing the buffers of the stream.
o Document the unicode slots in an fd-stream.

code/exports.lisp:
o Export +REPLACEMENT-CHARACTER-CODE+

surrogate or a lone trailing surrogate) get replaced with the
replacement character.

o Put back some unicode/unicode-bootstrap conditionals.

o Standard streams no longer change formats when
  *default-external-format* changes.  Use
  stream:set-system-external-format instead, or (setf
  external-format).
o char-to-octets properly handles surrogate characters being written.
o Makes simple-streams work again.

This change needs to be cross-compiled.  2009-07 binaries work for
cross-compiling using the 19e/boot-2008-05-cross-unicode-*.lisp
cross-compile script.

o Move the +ss-ef-foo+ constants to here from strategy.lisp, and
  update them so they don't overlap with existing +ef-foo+ constants.
o Update +ef-max+ accordingly.

pcl/simple-streams/impl.lisp:
o Use +ss-ef-str+ instead of +ef-str+ in simple-stream-strlen.

pcl/simple-streams/strategy.lisp:
o Comment out +ss-ef-foo+ constants.
o Use +ef-max+ instead of +ss-ef-max+, which is no longer defined.
o Fix bugs in %dc-write-chars-fn:
  - Use ef variable
  - Need to call flush-out-buffer, not flush-buffer for dual-channel
    streams.

correctly.  Previously, each surrogate was converted individually.
This is wrong; they should be treated as a single codepoint that is
converted.