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@sift.info wrote:
I just pulled a copy of flexi-streams, using asdf-install, and had a couple of minor problems:
- 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).
- 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.
"EW" == Edi Weitz edi@agharta.de writes:
[...snip...]
EW> On Thu, 1 Jun 2006 14:35:26 -0500, "Robert P. Goldman" EW> rpgoldman@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.
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.
flexi-streams-devel@common-lisp.net
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Edi Weitz -
rpgoldman＠real-time.com