is closed." -- implying that even though undesirable, early deletion
is legal. Restoring the original would none the less be the polite
thing to do.
+
+326: "*PRINT-CIRCLE* crosstalk between streams"
+ In sbcl-0.8.10.48 it's possible for *PRINT-CIRCLE* references to be
+ mixed between streams when output operations are intermingled closely
+ enough (as by doing output on S2 from within (PRINT-OBJECT X S1) in the
+ test case below), so that e.g. the references #2# appears on a stream
+ with no preceding #2= on that stream to define it (because the #2= was
+ sent to another stream).
+ (cl:in-package :cl-user)
+ (defstruct foo index)
+ (defparameter *foo* (make-foo :index 4))
+ (defstruct bar)
+ (defparameter *bar* (make-bar))
+ (defparameter *tangle* (list *foo* *bar* *foo*))
+ (defmethod print-object ((foo foo) stream)
+ (let ((index (foo-index foo)))
+ (format *trace-output*
+ "~&-$- emitting FOO ~D, ambient *BAR*=~S~%"
+ index *bar*)
+ (format stream "[FOO ~D]" index))
+ foo)
+ (let ((tsos (make-string-output-stream))
+ (ssos (make-string-output-stream)))
+ (let ((*print-circle* t)
+ (*trace-output* tsos)
+ (*standard-output* ssos))
+ (prin1 *tangle* *standard-output*))
+ (let ((string (get-output-stream-string ssos)))
+ (unless (string= string "(#1=[FOO 4] #S(BAR) #1#)")
+ ;; In sbcl-0.8.10.48 STRING was "(#1=[FOO 4] #2# #1#)".:-(
+ (error "oops: ~S" string))))
+ It might be straightforward to fix this by turning the
+ *CIRCULARITY-HASH-TABLE* and *CIRCULARITY-COUNTER* variables into
+ per-stream slots, but (1) it would probably be sort of messy faking
+ up the special variable binding semantics using UNWIND-PROTECT and
+ (2) it might be sort of a pain to test that no other bugs had been
+ introduced.
--- /dev/null
+contrib-doc-list.texi-temp
+docstrings
+*-stamp
+sbcl
+
SBCL is descended from CMUCL, which is itself descended from Spice
Lisp, including early implementations for the Mach operating system on
-the IBM RT, back in the 1980s. Design decisions from that time are
+the IBM RT, back in the 1980s. Some design decisions from that time are
still reflected in the current implementation:
@itemize
@ref{Efficiency}.
SBCL has diverged from CMUCL in that SBCL is now essentially a
-``compiler-only implementation'' of Common Lisp. A Common Lisp
-implementation is permitted to implement both a compiler and an
-interpreter, and there's some special support in the standard
-(e.g. the distinction between @code{functionp} and
-@code{compiled-function-p}) to help support that. But SBCL has only a
-vestigial, rudimentary true interpreter. In SBCL, the @code{eval}
-function only truly ``interprets'' a few special classes of forms,
-such as symbols which are @code{boundp}. More complicated forms are
-evaluated by calling @code{compile} and then calling @code{funcall} on
-the returned result.
+``compiler-only implementation'' of Common Lisp. This is a change in
+implementation strategy, taking advantage of the freedom ``any of these
+facilities might share the same execution strategy'' guaranteed in the
+ANSI specification section 3.1 (``Evaluation''). It does not mean SBCL
+can't be used interactively, and in fact the change is largely invisible
+to the casual user, since SBCL still can and does execute code
+interactively by compiling it on the fly. (It is visible if you know how
+to look, like using @code{compiled-function-p}; and it is visible in the
+way that that SBCL doesn't have many bugs which behave differently in
+interpreted code than in compiled code.) What it means is that in SBCL,
+the @code{eval} function only truly ``interprets'' a few easy kinds of
+forms, such as symbols which are @code{boundp}. More complicated forms
+are evaluated by calling @code{compile} and then calling @code{funcall}
+on the returned result.
The direct ancestor of SBCL is the x86 port of CMUCL. This port was in
some ways the most cobbled-together of all the CMUCL ports, since a
;; substitutes in arrays and structures as well as lists. The first arg is an
;; alist of the things to be replaced assoc'd with the things to replace them.
(defun circle-subst (old-new-alist tree)
- (cond ((not (typep tree '(or cons (array t) structure-object standard-object)))
+ (cond ((not (typep tree
+ '(or cons (array t) structure-object standard-object)))
(let ((entry (find tree old-new-alist :key #'second)))
(if entry (third entry) tree)))
((null (gethash tree *sharp-equal-circle-table*))
;;; checkins which aren't released. (And occasionally for internal
;;; versions, especially for internal versions off the main CVS
;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".)
-"0.8.10.50"
+"0.8.10.51"
projects / sbcl.git / commitdiff