From edi at agharta.de  Mon Jun 12 23:29:55 2006
From: edi at agharta.de (Edi Weitz)
Date: Tue, 13 Jun 2006 01:29:55 +0200
Subject: [flexi-streams-devel] New version 0.5.6
Message-ID: <uirn6dkb0.fsf@agharta.de>

ChangeLog:

  Version 0.5.6
  2006-06-13
  Fix Emacs mode lines (reported by Robert Goldman)

Download:

  http://weitz.de/files/flexi-streams.tar.gz


From edi at agharta.de  Mon Jun 12 23:43:06 2006
From: edi at agharta.de (Edi Weitz)
Date: Tue, 13 Jun 2006 01:43:06 +0200
Subject: [flexi-streams-devel] Re: note on flexi-streams
In-Reply-To: <17535.16766.323833.229209@necronomicon.sift.info> (Robert P.
	Goldman's message of "Thu, 1 Jun 2006 14:35:26 -0500")
References: <17535.16766.323833.229209@necronomicon.sift.info>
Message-ID: <uac8idjp1.fsf@agharta.de>

Hi!

So, I'm back from vacation now... :)

I'm Ccing the mailing list and I'd prefer if we could continue the
discussion there.  Thanks.

On Thu, 1 Jun 2006 14:35:26 -0500, "Robert P. Goldman" <rpgoldman at sift.info> wrote:

> I just pulled a copy of flexi-streams, using asdf-install, and had a
> couple of minor problems:
>
> 1.  The files have emacs mode lines which give a package name that
> seems like it might be an old nickname for flexi-streams (effbf).
> The in-package forms have the real package name.  I don't know what
> this does to slime, but it badly confuses ACL's emacs-lisp
> interface, which attends to the mode line in preference to the
> in-package form.

Thanks, I've fixed that and made a new release (0.5.6).

> 2.  Making a flexible stream with an external format blows up for me
> on ACL.  E.g., cl-irc tries to make a flexi-io-stream with external
> format (:utf-8 :eof-type :crlf)
>
> This value is stuffed into the flexi-stream slot EXTERNAL-FORMAT.
> Unfortunately, IIUC, this also triggers an Allegro-specific method
> as follows:
>
> (METHOD (SETF STREAM-EXTERNAL-FORMAT) :BEFORE (T STREAM))
>
> This method checks to make sure that the value you are setting as a
> stream-external-format is an excl:external-format object.  In this
> case, it clearly isn't, so the :before method hurls an error.
>
> I believe that this error is triggered because a flexi-io-stream ISA
> fundamental-binary-input-stream which ISA stream.
>
> I confess I'm not really sure what to do about this problem....

Hmm, at first glance I'd say that this is either an AllegroCL bug or
it is not related to FLEXI-STREAMS at all.  The slot you're talking
about above is called FLEXI-STREAMS::EXTERNAL-FORMAT, its name is not
exported from the package.  I can't see why setting the value of this
slot should trigger an Allegro-specific method.

(Note that on AllegroCL EXCL:EXTERNAL-FORMAT is accessible in various
packages, including CL-USER.  Maybe you're seeing a package conflict?)

It'd be nice if you could provide a simple test case which provokes
this error message, so we can see what's really going on.

> Here's an error backtrace:
>
> [1c] IRC(100): (setf str
> 	           (flexi-streams:make-flexi-stream
>                          network-stream
>                          :element-type 'character
>                          :external-format
> 					 (external-format-fixup
> 					 *default-outgoing-external-format*)
> 							 ))
> Error: `:EOL-STYLE' does not name an external-format.
>   [condition type: NO-EXTERNAL-FORMAT-ERROR]
>
> Restart actions (select using :continue):
>  0: Return to Debug Level 1 (an "abort" restart).
>  1: Try calling it again
>  2: Return to Top Level (an "abort" restart).
>  3: Abort entirely from this (lisp) process.
> [2] IRC(101): :bt
> Evaluation stack:
>
> (METHOD (SETF STREAM-EXTERNAL-FORMAT) :BEFORE ...) <-
>   (:INTERNAL (:EFFECTIVE-METHOD 2 NIL ...) 0) <-
>   (:INTERNAL (:EFFECTIVE-METHOD 2 T ...) 0) <-
>   (METHOD INITIALIZE-INSTANCE (STANDARD-OBJECT)) <-
>   (:INTERNAL (:EFFECTIVE-METHOD 1 T ...) 0) <- (METHOD MAKE-INSTANCE
>   (CLASS)) <-
>   (METHOD MAKE-INSTANCE (SYMBOL)) <- FLEX:MAKE-FLEXI-STREAM <- LET* <-
>   [... EXCL::%EVAL ] <- EVAL <- CERROR <- (METHOD NO-APPLICABLE-METHOD
>   (T)) <-
>   FLEX::TRANSLATE-CHAR <-
>   (METHOD EXCL:STREAM-WRITE-CHAR (FLEX:FLEXI-OUTPUT-STREAM T)) <-
>   (METHOD TRIVIAL-GRAY-STREAMS:STREAM-WRITE-SEQUENCE
>    (FLEX:FLEXI-OUTPUT-STREAM T T ...)) <-
>   [... TRIVIAL-GRAY-STREAMS:STREAM-WRITE-SEQUENCE ] <-
>   (METHOD EXCL:STREAM-WRITE-SEQUENCE
>    (TRIVIAL-GRAY-STREAMS:TRIVIAL-GRAY-STREAM-MIXIN T)) <-
>   (METHOD SEND-IRC-MESSAGE (CONNECTION T)) <- [... SEND-IRC-MESSAGE ]
>   <-
>   (METHOD NICK (CONNECTION STRING)) <- CONNECT <- BEIRC::COM-CONNECT
>   <-
>   (METHOD CLIM:EXECUTE-FRAME-COMMAND (CLIM:APPLICATION-FRAME T)) <-
>   (METHOD CLIM:ADOPT-FRAME :AFTER ...) <-
>   (:INTERNAL (:EFFECTIVE-METHOD 2 NIL ...) 0) <-
>   (METHOD CLIM:RUN-FRAME-TOP-LEVEL :AROUND ...) <-
>   (:INTERNAL (:EFFECTIVE-METHOD 1 T ...) 0) <-
>   [... CLIM:RUN-FRAME-TOP-LEVEL ] <-
>   (:INTERNAL BEIRC:BEIRC 0) <- BEIRC:BEIRC <- [... EXCL::%EVAL ] <-
>   EVAL <-
>   TPL:TOP-LEVEL-READ-EVAL-PRINT-LOOP <-
>   TPL:START-INTERACTIVE-TOP-LEVEL

Cheers,
Edi.


From rpgoldman at real-time.com  Tue Jun 13 15:05:25 2006
From: rpgoldman at real-time.com (rpgoldman at real-time.com)
Date: Tue, 13 Jun 2006 10:05:25 -0500
Subject: [flexi-streams-devel] Re: note on flexi-streams
In-Reply-To: <uac8idjp1.fsf@agharta.de>
References: <17535.16766.323833.229209@necronomicon.sift.info>
	<uac8idjp1.fsf@agharta.de>
Message-ID: <17550.54325.756445.667867@necronomicon.sift.info>

>>>>> "EW" == Edi Weitz <edi at agharta.de> writes:

[...snip...]

    EW> On Thu, 1 Jun 2006 14:35:26 -0500, "Robert P. Goldman"
    EW> <rpgoldman at sift.info> wrote:

    >> I just pulled a copy of flexi-streams, using asdf-install, and
    >> had a couple of minor problems:
    >>

[...snip...]

    >> 2.  Making a flexible stream with an external format blows up
    >>     for me
    >> on ACL.  E.g., cl-irc tries to make a flexi-io-stream with
    >> external format (:utf-8 :eof-type :crlf)
    >>
    >> This value is stuffed into the flexi-stream slot
    >> EXTERNAL-FORMAT.  Unfortunately, IIUC, this also triggers an
    >> Allegro-specific method as follows:
    >>
    >> (METHOD (SETF STREAM-EXTERNAL-FORMAT) :BEFORE (T STREAM))
    >>
    >> This method checks to make sure that the value you are setting
    >> as a stream-external-format is an excl:external-format object.
    >> In this case, it clearly isn't, so the :before method hurls an
    >> error.
    >>
    >> I believe that this error is triggered because a
    >> flexi-io-stream ISA fundamental-binary-input-stream which ISA
    >> stream.
    >>
    >> I confess I'm not really sure what to do about this problem....

    EW> Hmm, at first glance I'd say that this is either an AllegroCL
    EW> bug or it is not related to FLEXI-STREAMS at all.  The slot
    EW> you're talking about above is called
    EW> FLEXI-STREAMS::EXTERNAL-FORMAT, its name is not exported from
    EW> the package.  I can't see why setting the value of this slot
    EW> should trigger an Allegro-specific method.

    EW> (Note that on AllegroCL EXCL:EXTERNAL-FORMAT is accessible in
    EW> various packages, including CL-USER.  Maybe you're seeing a
    EW> package conflict?)

The problem is not the FLEXI-STREAMS::EXTERNAL-FORMAT symbol, but the
use of :external-format as an initarg, IIUC.  See the (relatively)
simple test case below for more details.

    EW> It'd be nice if you could provide a simple test case which
    EW> provokes this error message, so we can see what's really going
    EW> on.

OK.  Understand that I don't really know how flexi-streams are
supposed to work --- I just stumbled into this because I use BEIRC,
which uses CL-IRC, which (newly) uses FLEXI-STREAMS.  So I'm pretty
far from understanding things, and some of the things that I give may
not be bugs; they may be me using the package wrong.  

My first shot at causing an error is the following:

(defpackage :flexi-test (:use :common-lisp :flex))
(in-package :flexi-test)
(setf foo (open "/tmp/foo" :direction :io))
(setf bar (make-flexi-stream foo))
Error: :DEFAULT is not known to be a name for an external format.

Restart actions (select using :continue):
 0: Return to Top Level (an "abort" restart).
 1: Abort entirely from this (lisp) process.
[1] FLEXI-TEST(18): :bt
Evaluation stack:

FLEX::NORMALIZE-EXTERNAL-FORMAT-NAME <-
  FLEX::MAKE-EXTERNAL-FORMAT% <- MAKE-EXTERNAL-FORMAT <-
  FLEX::MAYBE-CONVERT-EXTERNAL-FORMAT <-
  (METHOD INITIALIZE-INSTANCE :AFTER ...) <-
  (:INTERNAL (:EFFECTIVE-METHOD 1 T ...) 0) <-
  (METHOD MAKE-INSTANCE (CLASS)) <- (METHOD MAKE-INSTANCE (SYMBOL)) <-
  MAKE-FLEXI-STREAM <- [... EXCL::%EVAL ] <- LET* <- [... EXCL::%EVAL ] <-
  EVAL <- TPL:TOP-LEVEL-READ-EVAL-PRINT-LOOP <- TPL:START-INTERACTIVE-TOP-LEVEL

[I'm honestly not sure where the :default value comes from, and it may
be that I am simply committing an error here and that the
:external-format keyword is mandatory, rather than optional, as I have
treated it.]

So I tried to do what cl-irc does:

(defun external-format-fixup (format)
  (let ((new-format (copy-list format)))
    (setf (getf (cdr new-format) :eol-style) :crlf)
    new-format))
(defun mock-connect (&key (server "irc.freenode.net")
					  (port 6667)
					  (connection-type 'connection)
                     (logging-stream t))
		  (let* ((stream (socket-connect server port))
			 (connection (make-connection :connection-type connection-type
                                      :network-stream stream
                                      :client-stream logging-stream
                                      :server-name server)))
		    (values connection stream)))
(defun make-connection (&key (connection-type 'connection)
                             (user nil)
                             (password nil)
                             (server-name "")
                             (server-port nil)
                             (network-stream nil)
                             (outgoing-external-format *default-outgoing-external-format*)
                             (client-stream t)
                             (hooks nil))
  (let ((output-stream (flexi-streams:make-flexi-stream
                         network-stream
                         :element-type 'character
                         :external-format (external-format-fixup outgoing-external-format))))
	output-stream))
;; overlooked this dependency....	
(asdf:oos 'asdf:load-op :trivial-sockets)
(defun socket-connect (server port)
  "Create a socket connected to `server':`port' and return stream for it."
  (trivial-sockets:open-stream server port :element-type '(unsigned-byte 8)))    
(setf *default-outgoing-external-format* '(:utf8))
That gets me the error:
FLEXI-TEST(62): (mock-connect)
Error: `:EOL-STYLE' does not name an external-format.
  [condition type: NO-EXTERNAL-FORMAT-ERROR]

Restart actions (select using :continue):
 0: Return to Top Level (an "abort" restart).
 1: Abort entirely from this (lisp) process.
[1] FLEXI-TEST(63): :bt
Evaluation stack:

(METHOD (SETF STREAM-EXTERNAL-FORMAT) :BEFORE ...) <-
  (:INTERNAL (:EFFECTIVE-METHOD 2 NIL ...) 0) <-
  (:INTERNAL (:EFFECTIVE-METHOD 2 T ...) 0) <-
  (METHOD INITIALIZE-INSTANCE (STANDARD-OBJECT)) <-
  (:INTERNAL (:EFFECTIVE-METHOD 1 T ...) 0) <-
  (METHOD MAKE-INSTANCE (CLASS)) <- (METHOD MAKE-INSTANCE (SYMBOL)) <-
  MAKE-FLEXI-STREAM <- LET <- MAKE-CONNECTION <- LET* <- MOCK-CONNECT <-
  EVAL <- TPL:TOP-LEVEL-READ-EVAL-PRINT-LOOP <- TPL:START-INTERACTIVE-TOP-LEVEL

The error happens when making the flexi-io-stream class.  It triggers
this ACL :before method that checks the value of the
stream-external-format, and which seems to be seeing the 
'(:utf8 :eol-style :crlf) value that cl-irc is stuffing into the
flexi-stream constructor.

ACL has a method that evidently checks the assignment to
stream-external-format for every stream to make sure that it is a
legitimate excl-external-format, IIUC.  A flexi-stream ISA stream, so
somehow this is triggered.  Your email seems to suggest that you did
NOT expect the flexi-stream-value to become the
stream-external-format, right?  But this is the make-instance call:

((METHOD MAKE-INSTANCE (CLASS)) #<STANDARD-CLASS FLEXI-IO-STREAM> :STREAM
 #<MULTIVALENT stream socket connected from 192.168.1.18/41332 to
   kornbluth.freenode.net/6667 @ #x71dc7412>
 :ELEMENT-TYPE CHARACTER :EXTERNAL-FORMAT (:UTF8 :EOL-STYLE :CRLF))

So even though flexi-streams::external-format is not exported,
flexi-streams is using the :external-format keyword in its
make-instance call, and that is triggering the ACL code.  Would it be
enough to fix things to change the :initarg to
":flexi-stream-external-format"?  That seems cumbersome, though.  I
don't know another way to keep ACL from grabbing up the
:external-format keyword arg, though...  But again, I have not thought
deeply about this.




From edi at agharta.de  Tue Jun 13 22:12:54 2006
From: edi at agharta.de (Edi Weitz)
Date: Wed, 14 Jun 2006 00:12:54 +0200
Subject: [flexi-streams-devel] Re: note on flexi-streams
In-Reply-To: <17550.54325.756445.667867@necronomicon.sift.info>
	(rpgoldman@real-time.com's
	message of "Tue, 13 Jun 2006 10:05:25 -0500")
References: <17535.16766.323833.229209@necronomicon.sift.info>
	<uac8idjp1.fsf@agharta.de>
	<17550.54325.756445.667867@necronomicon.sift.info>
Message-ID: <uver4hfh5.fsf@agharta.de>

I think you're basically right and what happens is this:

  CL-USER> (defclass foo (excl::fundamental-character-stream)
                ((bar :initarg :external-format
                      :initform (error "No external format."))))
  #<STANDARD-CLASS FOO>
  CL-USER> (make-instance 'foo)
  #<FOO @ #x2122c9aa>
  CL-USER> (slot-value * 'bar)
  :DEFAULT

So, it looks like there's some :AROUND method within AllegroCL which
modifies the initargs before the FOO instance is initialized.  I
couldn't find a place in their documentation where they explicitely
talk about the :EXTERNAL-FORMAT initarg, and I'm hesitant to rename it
in FLEXI-STREAMS because it is the right name, isn't it?

At least, before I do that, it'd be nice if you could ask Franz about
their take.

Cheers,
Edi.


From rpgoldman at real-time.com  Tue Jun 13 22:23:07 2006
From: rpgoldman at real-time.com (rpgoldman at real-time.com)
Date: Tue, 13 Jun 2006 17:23:07 -0500
Subject: [flexi-streams-devel] Issue with flexi-streams
Message-ID: <17551.15051.913400.697344@necronomicon.sift.info>


I have been having some trouble using the publicly available
flexi-streams package (http://www.cliki.net/flexi-streams).  The
flexi-streams package is described as follows:

FLEXI-STREAMS is a library which implements "virtual" bivalent streams
that can be layered atop real binary/bivalent streams. It can be used
to read and write character data in various single- or multi-octet
encodings which can be changed on the fly. It also supplies in-memory
binary streams which are similar to string streams.



Here's the problem:  the flexi-stream library defines a flexi-stream
class which ISA stream and has an EXTERNAL-FORMAT slot (and an
:external-format initarg):

(defclass flexi-stream (trivial-gray-stream-mixin)
  ((stream :initarg :stream
           :reader flexi-stream-stream
           :documentation "The actual stream that's used for
input and/or output.  It must be capable of reading/writing
octets with READ-SEQUENCE and/or WRITE-SEQUENCE.")
   (external-format :initform (make-external-format :iso-8859-1)
                    :initarg :external-format
                    :accessor flexi-stream-external-format
                    :documentation "The encoding currently used
by this stream.  Can be changed on the fly.")
   (element-type :initform #+:lispworks 'lw:simple-char #-:lispworks 'character
                 :initarg :element-type
                 :accessor flexi-stream-element-type
                 :documentation "The element type of this stream.
Must be a subtype of CHARACTER."))
  (:documentation "A FLEXI-STREAM object is a stream that's
`layered' atop an existing binary/bivalent stream in order to
allow for multi-octet external formats.  FLEXI-STREAM itself is a
mixin and should not be instantiated."))

Flexi-streams allow this initarg to be a list of symbols.
Unfortunately, calling MAKE-INSTANCE on a flexi-stream blows up on ACL
because ACL has a :BEFORE method for (setf external-format) on STREAM,
which rejects the flexi-stream lists that are supplied as initargs.  I
am not entirely sure why this is being triggered.  

Here is an email that specifies what is going wrong, with a simple
test case that you can cut out and run under ACL, and a response from
the flexi-stream builder.

>>>>> "RPG" == rpgoldman  <rpgoldman at real-time.com> writes:

>>>>> "EW" == Edi Weitz <edi at agharta.de> writes:
    RPG> [...snip...]

    EW> On Thu, 1 Jun 2006 14:35:26 -0500, "Robert P. Goldman"
    EW> <rpgoldman at sift.info> wrote:

    >>> I just pulled a copy of flexi-streams, using asdf-install, and
    >>> had a couple of minor problems:
    >>>

    RPG> [...snip...]

    >>> 2.  Making a flexible stream with an external format blows up
    >>> for me on ACL.  E.g., cl-irc tries to make a flexi-io-stream
    >>> with external format (:utf-8 :eof-type :crlf)
    >>>
    >>> This value is stuffed into the flexi-stream slot
    >>> EXTERNAL-FORMAT.  Unfortunately, IIUC, this also triggers an
    >>> Allegro-specific method as follows:
    >>>
    >>> (METHOD (SETF STREAM-EXTERNAL-FORMAT) :BEFORE (T STREAM))
    >>>
    >>> This method checks to make sure that the value you are setting
    >>> as a stream-external-format is an excl:external-format object.
    >>> In this case, it clearly isn't, so the :before method hurls an
    >>> error.
    >>>
    >>> I believe that this error is triggered because a
    >>> flexi-io-stream ISA fundamental-binary-input-stream which ISA
    >>> stream.
    >>>
    >>> I confess I'm not really sure what to do about this
    >>> problem....

    EW> Hmm, at first glance I'd say that this is either an AllegroCL
    EW> bug or it is not related to FLEXI-STREAMS at all.  The slot
    EW> you're talking about above is called
    EW> FLEXI-STREAMS::EXTERNAL-FORMAT, its name is not exported from
    EW> the package.  I can't see why setting the value of this slot
    EW> should trigger an Allegro-specific method.

    EW> (Note that on AllegroCL EXCL:EXTERNAL-FORMAT is accessible in
    EW> various packages, including CL-USER.  Maybe you're seeing a
    EW> package conflict?)

    RPG> The problem is not the FLEXI-STREAMS::EXTERNAL-FORMAT symbol,
    RPG> but the use of :external-format as an initarg, IIUC.  See the
    RPG> (relatively) simple test case below for more details.

    EW> It'd be nice if you could provide a simple test case which
    EW> provokes this error message, so we can see what's really going
    EW> on.

    RPG> OK.  Understand that I don't really know how flexi-streams
    RPG> are supposed to work --- I just stumbled into this because I
    RPG> use BEIRC, which uses CL-IRC, which (newly) uses
    RPG> FLEXI-STREAMS.  So I'm pretty far from understanding things,
    RPG> and some of the things that I give may not be bugs; they may
    RPG> be me using the package wrong.

    RPG> My first shot at causing an error is the following:

    RPG> (defpackage :flexi-test (:use :common-lisp :flex))
    RPG> (in-package :flexi-test) (setf foo (open "/tmp/foo"
    RPG> :direction :io)) (setf bar (make-flexi-stream foo)) Error:
    RPG> :DEFAULT is not known to be a name for an external format.

    RPG> Restart actions (select using :continue):
    RPG>  0: Return to Top Level (an "abort" restart).  1: Abort
    RPG>  entirely from this (lisp) process.
    RPG> [1] FLEXI-TEST(18): :bt Evaluation stack:

    RPG> FLEX::NORMALIZE-EXTERNAL-FORMAT-NAME <-
    RPG>   FLEX::MAKE-EXTERNAL-FORMAT% <- MAKE-EXTERNAL-FORMAT <-
    RPG>   FLEX::MAYBE-CONVERT-EXTERNAL-FORMAT <- (METHOD
    RPG>   INITIALIZE-INSTANCE :AFTER ...) <- (:INTERNAL
    RPG>   (:EFFECTIVE-METHOD 1 T ...) 0) <- (METHOD MAKE-INSTANCE
    RPG>   (CLASS)) <- (METHOD MAKE-INSTANCE (SYMBOL)) <-
    RPG>   MAKE-FLEXI-STREAM <- [... EXCL::%EVAL ] <- LET* <-
    RPG>   [... EXCL::%EVAL ] <- EVAL <-
    RPG>   TPL:TOP-LEVEL-READ-EVAL-PRINT-LOOP <-
    RPG>   TPL:START-INTERACTIVE-TOP-LEVEL

    RPG> [I'm honestly not sure where the :default value comes from,
    RPG> and it may be that I am simply committing an error here and
    RPG> that the :external-format keyword is mandatory, rather than
    RPG> optional, as I have treated it.]

    RPG> So I tried to do what cl-irc does:

    RPG> (defun external-format-fixup (format)
    RPG>   (let ((new-format (copy-list format)))
    RPG>     (setf (getf (cdr new-format) :eol-style) :crlf)
    RPG>     new-format))
    RPG> (defun mock-connect (&key (server "irc.freenode.net")
    RPG> 					  (port 6667)
    RPG> 					  (connection-type
    RPG> 					  'connection)
    RPG>                      (logging-stream t))
    RPG> 		  (let* ((stream (socket-connect server port))
    RPG> 			 (connection (make-connection
    RPG> 			 :connection-type connection-type
    RPG>                                       :network-stream stream
    RPG>                                       :client-stream
    RPG>                                       logging-stream
    RPG>                                       :server-name server)))
    RPG> 		    (values connection stream)))
    RPG> (defun make-connection (&key (connection-type 'connection)
    RPG>                              (user nil) (password nil)
    RPG>                              (server-name "") (server-port
    RPG>                              nil) (network-stream nil)
    RPG>                              (outgoing-external-format
    RPG>                              *default-outgoing-external-format*)
    RPG>                              (client-stream t) (hooks nil))
    RPG>   (let ((output-stream (flexi-streams:make-flexi-stream
    RPG>                          network-stream :element-type
    RPG>                          'character :external-format
    RPG>                          (external-format-fixup
    RPG>                          outgoing-external-format))))
    RPG> 	output-stream))
    RPG> ;; overlooked this dependency....
    RPG> (asdf:oos 'asdf:load-op :trivial-sockets) (defun
    RPG> socket-connect (server port)
    RPG>   "Create a socket connected to `server':`port' and return
    RPG>   stream for it."  (trivial-sockets:open-stream server port
    RPG>   :element-type '(unsigned-byte 8)))
    RPG> (setf *default-outgoing-external-format* '(:utf8)) That gets
    RPG> me the error: FLEXI-TEST(62): (mock-connect) Error:
    RPG> `:EOL-STYLE' does not name an external-format.
    RPG>   [condition type: NO-EXTERNAL-FORMAT-ERROR]

    RPG> Restart actions (select using :continue):
    RPG>  0: Return to Top Level (an "abort" restart).  1: Abort
    RPG>  entirely from this (lisp) process.
    RPG> [1] FLEXI-TEST(63): :bt Evaluation stack:

    RPG> (METHOD (SETF STREAM-EXTERNAL-FORMAT) :BEFORE ...) <-
    RPG>   (:INTERNAL (:EFFECTIVE-METHOD 2 NIL ...) 0) <- (:INTERNAL
    RPG>   (:EFFECTIVE-METHOD 2 T ...) 0) <- (METHOD
    RPG>   INITIALIZE-INSTANCE (STANDARD-OBJECT)) <- (:INTERNAL
    RPG>   (:EFFECTIVE-METHOD 1 T ...) 0) <- (METHOD MAKE-INSTANCE
    RPG>   (CLASS)) <- (METHOD MAKE-INSTANCE (SYMBOL)) <-
    RPG>   MAKE-FLEXI-STREAM <- LET <- MAKE-CONNECTION <- LET* <-
    RPG>   MOCK-CONNECT <- EVAL <- TPL:TOP-LEVEL-READ-EVAL-PRINT-LOOP
    RPG>   <- TPL:START-INTERACTIVE-TOP-LEVEL

    RPG> The error happens when making the flexi-io-stream class.  It
    RPG> triggers this ACL :before method that checks the value of the
    RPG> stream-external-format, and which seems to be seeing the
    RPG> '(:utf8 :eol-style :crlf) value that cl-irc is stuffing into
    RPG> the flexi-stream constructor.

    RPG> ACL has a method that evidently checks the assignment to
    RPG> stream-external-format for every stream to make sure that it
    RPG> is a legitimate excl-external-format, IIUC.  A flexi-stream
    RPG> ISA stream, so somehow this is triggered.  Your email seems
    RPG> to suggest that you did NOT expect the flexi-stream-value to
    RPG> become the stream-external-format, right?  But this is the
    RPG> make-instance call:

    RPG> ((METHOD MAKE-INSTANCE (CLASS)) #<STANDARD-CLASS
    RPG> FLEXI-IO-STREAM> :STREAM
    RPG>  #<MULTIVALENT stream socket connected from
    RPG>  #192.168.1.18/41332 to
    RPG>    kornbluth.freenode.net/6667 @ #x71dc7412>
    RPG>  :ELEMENT-TYPE CHARACTER :EXTERNAL-FORMAT (:UTF8 :EOL-STYLE
    RPG>  :CRLF))

    RPG> So even though flexi-streams::external-format is not
    RPG> exported, flexi-streams is using the :external-format keyword
    RPG> in its make-instance call, and that is triggering the ACL
    RPG> code.  Would it be enough to fix things to change the
    RPG> :initarg to ":flexi-stream-external-format"?  That seems
    RPG> cumbersome, though.  I don't know another way to keep ACL
    RPG> from grabbing up the :external-format keyword arg, though...
    RPG> But again, I have not thought deeply about this.






>>>>> "EW" == Edi Weitz <edi at agharta.de> writes:

    EW> I think you're basically right and what happens is this:

    CL-USER> (defclass foo (excl::fundamental-character-stream)
    EW>                 ((bar :initarg :external-format
    EW>                       :initform (error "No external
    EW>                       format."))))
    EW>   #<STANDARD-CLASS FOO>
    CL-USER> (make-instance 'foo)
    EW>   #<FOO @ #x2122c9aa>
    CL-USER> (slot-value * 'bar)
    EW>   :DEFAULT

    EW> So, it looks like there's some :AROUND method within AllegroCL
    EW> which modifies the initargs before the FOO instance is
    EW> initialized.  I couldn't find a place in their documentation
    EW> where they explicitely talk about the :EXTERNAL-FORMAT
    EW> initarg, and I'm hesitant to rename it in FLEXI-STREAMS
    EW> because it is the right name, isn't it?

    EW> At least, before I do that, it'd be nice if you could ask
    EW> Franz about their take.

    EW> Cheers, Edi.


-- 
Robert P. Goldman
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From edi at agharta.de  Wed Jun 14 18:24:31 2006
From: edi at agharta.de (Edi Weitz)
Date: Wed, 14 Jun 2006 20:24:31 +0200
Subject: [flexi-streams-devel] Re: [spr31726] Issue with flexi-streams
In-Reply-To: <200606141802.k5EI2DR13780@gemini.franz.com> (Charles A. Cox's
	message of "Wed, 14 Jun 2006 11:02:13 -0700")
References: <200606141802.k5EI2DR13780@gemini.franz.com>
Message-ID: <u4pynr3xc.fsf@agharta.de>

On Wed, 14 Jun 2006 11:02:13 -0700, "Charles A. Cox" <cox at franz.com> wrote:

>   Thanks for your report.
>
>   This is the first time I've heard of "flexi-streams".  From the
> description in your message, my first thought is that Allegro CL
> users are better off using Allegro CL streams since Allegro CL
> streams provide what "flexi-streams" purports to offer (bivalency,
> dynamically switchable external-formats, etc.).
>
>   Still, if I understand correctly, there is a specific question of
> how the :external-format slot is being initialized in subclasses of
> excl:fundamental-character-stream.  That class has a
> default-initargs which specifies :external-format.  Here is a
> simplified example to demonstrate what's happening:
>
>  (defclass my-stream ()
>    ((external-format :initarg :external-format)))
>
>  (defclass my-fundamental-character-stream (my-stream)
>    ()
>    (:default-initargs :external-format :default))
>
>  [your test case:]
>  (defclass foo (my-fundamental-character-stream)
>    ((bar :initarg :external-format
> 	 :initform (error "No external format."))))
>
>  (slot-value (make-instance 'foo) 'bar) ==> :default
>
>   Even though we may not be documenting the external-format slot in
> Allegro CL streams, we do document stream-external-format, which is
> an accessor to that slot.
>
>   My recommendation is that if flexi-streams implements an
> external-format separate from that of the base Lisp, that it then
> use a name other than "external-format".

Well, you've heard what they say - AllegroCL's streams are better
anyway... :)

My take still is that if AllegroCL provides classes that can be
subclassed and instantiated by user code, then they should either use
internal symbols for their initargs or, if they use keyword symbols,
they should document them.

Anyway, Franz' reaction doesn't really make me feel as if I should
hurry to make FLEXI-STREAMS work with AllegroCL.

Cheers,
Edi.


From edi at agharta.de  Thu Jun 29 13:37:59 2006
From: edi at agharta.de (Edi Weitz)
Date: Thu, 29 Jun 2006 15:37:59 +0200
Subject: [flexi-streams-devel] New version 0.5.7
Message-ID: <upsgsaxqg.fsf@agharta.de>

ChangeLog:

  Version 0.5.7
  2006-06-29
  Removed incompatibility with AllegroCL, see mailing list archive for details

Download:

  http://weitz.de/files/flexi-streams.tar.gz