[Sbcl-help] Strange behaviour when changing #\linefeed in readtable

[Lynn W. <owi...@in...>]

I'm using SBCL 0.9.18.  Can anyone confirm that the following code leads 
to an error?  I was also redefining #\( and #\;, but the error seems to 
correspond only to redefining linefeed.  [I'm trying to write a program 
to map source code comments to the defined names/types which they describe].

Thanks,
Lynn

(defvar cataloging-readtable nil)

(defun read-newline (stream ignore)
   (declare (ignore ignore))
   (declare (ignore stream))
   (values))

(defun init-comment-cataloging-readtable ()
   (setq cataloging-readtable (copy-readtable nil))
   (set-syntax-from-char  #\linefeed #\; cataloging-readtable 
cataloging-readtable)
   (set-macro-character #\linefeed #'read-newline cataloging-readtable 
cataloging-readtable)
  )

(defun cataloging-read (stream)
   (let ((rt *readtable*)
	(result nil))
     (setq *readtable* cataloging-readtable)
     (unwind-protect (setq result (read stream nil :eof nil))
       (setq *readtable* rt)
       result)))

(init-comment-cataloging-readtable)

(cataloging-read *standard-input*)
ooooo
====>
READER-ERROR on #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}>:
invalid constituent
    [Condition of type READER-ERROR]

Restarts:
   0: [ABORT-REQUEST] Abort handling SLIME request.
   1: [TERMINATE-THREAD] Terminate this thread (#<THREAD "repl-thread" 
{AA0E7E9}>)

Backtrace:
   0: (SB-IMPL::%READER-ERROR #<SWANK-BACKEND::SLIME-INPUT-STREAM 
{A9FF1D1}> "invalid constituent")
       Locals:
         SB-DEBUG::ARG-0 = 2
         SB-DEBUG::ARG-1 = #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}>
         SB-DEBUG::ARG-2 = "invalid constituent"
   1: (SB-IMPL::READ-TOKEN #<SWANK-BACKEND::SLIME-INPUT-STREAM 
{A9FF1D1}> #\o)
       Locals:
         SB-DEBUG::ARG-0 = 2
         SB-DEBUG::ARG-1 = #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}>
         SB-DEBUG::ARG-2 = #\o
   2: (READ-PRESERVING-WHITESPACE #<SWANK-BACKEND::SLIME-INPUT-STREAM 
{A9FF1D1}> NIL :EOF T)
       Locals:
         SB-IMPL::EOF-ERROR-P = NIL
         SB-IMPL::EOF-VALUE = :EOF
         SB-IMPL::RECURSIVEP = T
         STREAM = #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}>
   3: (READ-PRESERVING-WHITESPACE #<SWANK-BACKEND::SLIME-INPUT-STREAM 
{A9FF1D1}> NIL :EOF NIL)
       Locals:
         SB-IMPL::EOF-ERROR-P = NIL
         SB-IMPL::EOF-VALUE = :EOF
         SB-IMPL::RECURSIVEP = NIL
         STREAM = #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}>
   4: (READ #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}> NIL :EOF NIL)
       Locals:
         SB-IMPL::EOF-ERROR-P = NIL
         SB-IMPL::EOF-VALUE = :EOF
         SB-IMPL::RECURSIVEP = NIL
         STREAM = #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}>
   5: (CATALOGING-READ #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}>)
       Locals:
         SB-DEBUG::ARG-0 = #<SWANK-BACKEND::SLIME-INPUT-STREAM {A9FF1D1}>