3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This software is derived from the CMU CL system, which was
7 ;;;; written at Carnegie Mellon University and released into the
8 ;;;; public domain. The software is in the public domain and is
9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
10 ;;;; files for more information.
12 (in-package "SB!IMPL")
14 ;;;; exported printer control variables
16 ;;; FIXME: Many of these have nontrivial types, e.g. *PRINT-LEVEL*,
17 ;;; *PRINT-LENGTH*, and *PRINT-LINES* are (OR NULL UNSIGNED-BYTE).
19 (defvar *print-readably* nil
21 "If true, all objects will printed readably. If readable printing is
22 impossible, an error will be signalled. This overrides the value of
24 (defvar *print-escape* T
26 "Should we print in a reasonably machine-readable way? (possibly
27 overridden by *PRINT-READABLY*)")
28 (defvar *print-pretty* nil ; (set later when pretty-printer is initialized)
30 "Should pretty printing be used?")
31 (defvar *print-base* 10.
33 "the output base for RATIONALs (including integers)")
34 (defvar *print-radix* nil
36 "Should base be verified when printing RATIONALs?")
37 (defvar *print-level* nil
39 "How many levels should be printed before abbreviating with \"#\"?")
40 (defvar *print-length* nil
42 "How many elements at any level should be printed before abbreviating
44 (defvar *print-circle* nil
46 "Should we use #n= and #n# notation to preserve uniqueness in general (and
47 circularity in particular) when printing?")
48 (defvar *print-case* :upcase
50 "What case should the printer should use default?")
51 (defvar *print-array* t
53 "Should the contents of arrays be printed?")
54 (defvar *print-gensym* t
56 "Should #: prefixes be used when printing symbols with null SYMBOL-PACKAGE?")
57 (defvar *print-lines* nil
59 "the maximum number of lines to print per object")
60 (defvar *print-right-margin* nil
62 "the position of the right margin in ems (for pretty-printing)")
63 (defvar *print-miser-width* nil
65 "If the remaining space between the current column and the right margin
66 is less than this, then print using ``miser-style'' output. Miser
67 style conditional newlines are turned on, and all indentations are
68 turned off. If NIL, never use miser mode.")
69 (defvar *print-pprint-dispatch*)
71 (setf (fdocumentation '*print-pprint-dispatch* 'variable)
72 "the pprint-dispatch-table that controls how to pretty-print objects")
74 (defmacro with-standard-io-syntax (&body body)
76 "Bind the reader and printer control variables to values that enable READ
77 to reliably read the results of PRINT. These values are:
78 *PACKAGE* the COMMON-LISP-USER package
88 *PRINT-MISER-WIDTH* NIL
92 *PRINT-RIGHT-MARGIN* NIL
94 *READ-DEFAULT-FLOAT-FORMAT* SINGLE-FLOAT
97 *READTABLE* the standard readtable"
98 `(%with-standard-io-syntax (lambda () ,@body)))
100 (defun %with-standard-io-syntax (function)
101 (declare (type function function))
102 (let ((*package* (find-package "COMMON-LISP-USER"))
105 (*print-case* :upcase)
112 (*print-miser-width* nil)
116 (*print-right-margin* nil)
118 (*read-default-float-format* 'single-float)
120 (*read-suppress* nil)
121 ;; FIXME: It doesn't seem like a good idea to expose our
122 ;; disaster-recovery *STANDARD-READTABLE* here. What if some
123 ;; enterprising user corrupts the disaster-recovery readtable
124 ;; by doing destructive readtable operations within
125 ;; WITH-STANDARD-IO-SYNTAX? Perhaps we should do a
126 ;; COPY-READTABLE? The consing would be unfortunate, though.
127 (*readtable* *standard-readtable*))
130 ;;;; routines to print objects
132 (defun write (object &key
133 ((:stream stream) *standard-output*)
134 ((:escape *print-escape*) *print-escape*)
135 ((:radix *print-radix*) *print-radix*)
136 ((:base *print-base*) *print-base*)
137 ((:circle *print-circle*) *print-circle*)
138 ((:pretty *print-pretty*) *print-pretty*)
139 ((:level *print-level*) *print-level*)
140 ((:length *print-length*) *print-length*)
141 ((:case *print-case*) *print-case*)
142 ((:array *print-array*) *print-array*)
143 ((:gensym *print-gensym*) *print-gensym*)
144 ((:readably *print-readably*) *print-readably*)
145 ((:right-margin *print-right-margin*)
146 *print-right-margin*)
147 ((:miser-width *print-miser-width*)
149 ((:lines *print-lines*) *print-lines*)
150 ((:pprint-dispatch *print-pprint-dispatch*)
151 *print-pprint-dispatch*))
153 "Output OBJECT to the specified stream, defaulting to *STANDARD-OUTPUT*"
154 (output-object object (out-synonym-of stream))
157 (defun prin1 (object &optional stream)
159 "Output a mostly READable printed representation of OBJECT on the specified
161 (let ((*print-escape* t))
162 (output-object object (out-synonym-of stream)))
165 (defun princ (object &optional stream)
167 "Output an aesthetic but not necessarily READable printed representation
168 of OBJECT on the specified STREAM."
169 (let ((*print-escape* nil)
170 (*print-readably* nil))
171 (output-object object (out-synonym-of stream)))
174 (defun print (object &optional stream)
176 "Output a newline, the mostly READable printed representation of OBJECT, and
177 space to the specified STREAM."
178 (let ((stream (out-synonym-of stream)))
180 (prin1 object stream)
181 (write-char #\space stream)
184 (defun pprint (object &optional stream)
186 "Prettily output OBJECT preceded by a newline."
187 (let ((*print-pretty* t)
189 (stream (out-synonym-of stream)))
191 (output-object object stream))
194 (defun write-to-string
196 ((:escape *print-escape*) *print-escape*)
197 ((:radix *print-radix*) *print-radix*)
198 ((:base *print-base*) *print-base*)
199 ((:circle *print-circle*) *print-circle*)
200 ((:pretty *print-pretty*) *print-pretty*)
201 ((:level *print-level*) *print-level*)
202 ((:length *print-length*) *print-length*)
203 ((:case *print-case*) *print-case*)
204 ((:array *print-array*) *print-array*)
205 ((:gensym *print-gensym*) *print-gensym*)
206 ((:readably *print-readably*) *print-readably*)
207 ((:right-margin *print-right-margin*) *print-right-margin*)
208 ((:miser-width *print-miser-width*) *print-miser-width*)
209 ((:lines *print-lines*) *print-lines*)
210 ((:pprint-dispatch *print-pprint-dispatch*)
211 *print-pprint-dispatch*))
213 "Return the printed representation of OBJECT as a string."
214 (stringify-object object))
216 (defun prin1-to-string (object)
218 "Return the printed representation of OBJECT as a string with
220 (let ((*print-escape* t))
221 (stringify-object object)))
223 (defun princ-to-string (object)
225 "Return the printed representation of OBJECT as a string with
227 (let ((*print-escape* nil)
228 (*print-readably* nil))
229 (stringify-object object)))
231 ;;; This produces the printed representation of an object as a string.
232 ;;; The few ...-TO-STRING functions above call this.
233 (defvar *string-output-streams* ())
234 (defun stringify-object (object)
235 (let ((stream (if *string-output-streams*
236 (pop *string-output-streams*)
237 (make-string-output-stream))))
238 (setup-printer-state)
239 (output-object object stream)
241 (get-output-stream-string stream)
242 (push stream *string-output-streams*))))
244 ;;;; support for the PRINT-UNREADABLE-OBJECT macro
246 ;;; guts of PRINT-UNREADABLE-OBJECT
247 (defun %print-unreadable-object (object stream type identity body)
248 (declare (type (or null function) body))
249 (when *print-readably*
250 (error 'print-not-readable :object object))
251 (flet ((print-description ()
253 (write (type-of object) :stream stream :circle nil
254 :level nil :length nil)
255 (write-char #\space stream))
259 (when (or body (not type))
260 (write-char #\space stream))
261 (write-char #\{ stream)
262 (write (get-lisp-obj-address object) :stream stream
264 (write-char #\} stream))))
265 (cond ((print-pretty-on-stream-p stream)
266 ;; Since we're printing prettily on STREAM, format the
267 ;; object within a logical block. PPRINT-LOGICAL-BLOCK does
268 ;; not rebind the stream when it is already a pretty stream,
269 ;; so output from the body will go to the same stream.
270 (pprint-logical-block (stream nil :prefix "#<" :suffix ">")
271 (print-description)))
273 (write-string "#<" stream)
275 (write-char #\> stream))))
278 ;;;; circularity detection stuff
280 ;;; When *PRINT-CIRCLE* is T, this gets bound to a hash table that
281 ;;; (eventually) ends up with entries for every object printed. When
282 ;;; we are initially looking for circularities, we enter a T when we
283 ;;; find an object for the first time, and a 0 when we encounter an
284 ;;; object a second time around. When we are actually printing, the 0
285 ;;; entries get changed to the actual marker value when they are first
287 (defvar *circularity-hash-table* nil)
289 ;;; When NIL, we are just looking for circularities. After we have
290 ;;; found them all, this gets bound to 0. Then whenever we need a new
291 ;;; marker, it is incremented.
292 (defvar *circularity-counter* nil)
294 ;;; Check to see whether OBJECT is a circular reference, and return
295 ;;; something non-NIL if it is. If ASSIGN is T, then the number to use
296 ;;; in the #n= and #n# noise is assigned at this time.
297 ;;; If ASSIGN is true, reference bookkeeping will only be done for
298 ;;; existing entries, no new references will be recorded!
300 ;;; Note: CHECK-FOR-CIRCULARITY must be called *exactly* once with
301 ;;; ASSIGN true, or the circularity detection noise will get confused
302 ;;; about when to use #n= and when to use #n#. If this returns non-NIL
303 ;;; when ASSIGN is true, then you must call HANDLE-CIRCULARITY on it.
304 ;;; If CHECK-FOR-CIRCULARITY returns :INITIATE as the second value,
305 ;;; you need to initiate the circularity detection noise, e.g. bind
306 ;;; *CIRCULARITY-HASH-TABLE* and *CIRCULARITY-COUNTER* to suitable values
307 ;;; (see #'OUTPUT-OBJECT for an example).
308 (defun check-for-circularity (object &optional assign)
309 (cond ((null *print-circle*)
310 ;; Don't bother, nobody cares.
312 ((null *circularity-hash-table*)
313 (values nil :initiate))
314 ((null *circularity-counter*)
315 (ecase (gethash object *circularity-hash-table*)
318 (setf (gethash object *circularity-hash-table*) t)
319 ;; We need to keep looking.
323 (setf (gethash object *circularity-hash-table*) 0)
324 ;; It's a circular reference.
327 ;; It's a circular reference.
330 (let ((value (gethash object *circularity-hash-table*)))
333 ;; If NIL, we found an object that wasn't there the
334 ;; first time around. If T, this object appears exactly
335 ;; once. Either way, just print the thing without any
336 ;; special processing. Note: you might argue that
337 ;; finding a new object means that something is broken,
338 ;; but this can happen. If someone uses the ~@<...~:>
339 ;; format directive, it conses a new list each time
340 ;; though format (i.e. the &REST list), so we will have
345 (let ((value (incf *circularity-counter*)))
346 ;; first occurrence of this object: Set the counter.
347 (setf (gethash object *circularity-hash-table*) value)
351 ;; second or later occurrence
354 ;;; Handle the results of CHECK-FOR-CIRCULARITY. If this returns T then
355 ;;; you should go ahead and print the object. If it returns NIL, then
356 ;;; you should blow it off.
357 (defun handle-circularity (marker stream)
360 ;; Someone forgot to initiate circularity detection.
361 (let ((*print-circle* nil))
362 (error "trying to use CHECK-FOR-CIRCULARITY when ~
363 circularity checking isn't initiated")))
365 ;; It's a second (or later) reference to the object while we are
366 ;; just looking. So don't bother groveling it again.
369 (write-char #\# stream)
370 (let ((*print-base* 10) (*print-radix* nil))
371 (cond ((minusp marker)
372 (output-integer (- marker) stream)
373 (write-char #\# stream)
376 (output-integer marker stream)
377 (write-char #\= stream)
380 ;;;; OUTPUT-OBJECT -- the main entry point
382 ;;; Objects whose print representation identifies them EQLly don't
383 ;;; need to be checked for circularity.
384 (defun uniquely-identified-by-print-p (x)
388 (symbol-package x))))
390 ;;; Output OBJECT to STREAM observing all printer control variables.
391 (defun output-object (object stream)
392 (labels ((print-it (stream)
394 (sb!pretty:output-pretty-object object stream)
395 (output-ugly-object object stream)))
397 (multiple-value-bind (marker initiate)
398 (check-for-circularity object t)
399 ;; initialization of the circulation detect noise ...
400 (if (eq initiate :initiate)
401 (let ((*circularity-hash-table*
402 (make-hash-table :test 'eq)))
403 (check-it (make-broadcast-stream))
404 (let ((*circularity-counter* 0))
408 (when (handle-circularity marker stream)
410 (print-it stream))))))
411 (cond (;; Maybe we don't need to bother with circularity detection.
412 (or (not *print-circle*)
413 (uniquely-identified-by-print-p object))
415 (;; If we have already started circularity detection, this
416 ;; object might be a shared reference. If we have not, then
417 ;; if it is a compound object it might contain a circular
418 ;; reference to itself or multiple shared references.
419 (or *circularity-hash-table*
420 (compound-object-p object))
423 (print-it stream)))))
425 ;;; a hack to work around recurring gotchas with printing while
426 ;;; DEFGENERIC PRINT-OBJECT is being built
428 ;;; (hopefully will go away naturally when CLOS moves into cold init)
429 (defvar *print-object-is-disabled-p*)
431 ;;; Output OBJECT to STREAM observing all printer control variables
432 ;;; except for *PRINT-PRETTY*. Note: if *PRINT-PRETTY* is non-NIL,
433 ;;; then the pretty printer will be used for any components of OBJECT,
434 ;;; just not for OBJECT itself.
435 (defun output-ugly-object (object stream)
437 ;; KLUDGE: The TYPECASE approach here is non-ANSI; the ANSI definition of
438 ;; PRINT-OBJECT says it provides printing and we're supposed to provide
439 ;; PRINT-OBJECT methods covering all classes. We deviate from this
440 ;; by using PRINT-OBJECT only when we print instance values. However,
441 ;; ANSI makes it hard to tell that we're deviating from this:
442 ;; (1) ANSI specifies that the user isn't supposed to call PRINT-OBJECT
444 ;; (2) ANSI (section 11.1.2.1.2) says it's undefined to define
445 ;; a method on an external symbol in the CL package which is
446 ;; applicable to arg lists containing only direct instances of
447 ;; standardized classes.
448 ;; Thus, in order for the user to detect our sleaziness in conforming
449 ;; code, he has to do something relatively obscure like
450 ;; (1) actually use tools like FIND-METHOD to look for PRINT-OBJECT
452 ;; (2) define a PRINT-OBJECT method which is specialized on the stream
453 ;; value (e.g. a Gray stream object).
454 ;; As long as no one comes up with a non-obscure way of detecting this
455 ;; sleaziness, fixing this nonconformity will probably have a low
456 ;; priority. -- WHN 2001-11-25
459 (output-symbol object stream)
460 (output-list object stream)))
462 (cond ((not (and (boundp '*print-object-is-disabled-p*)
463 *print-object-is-disabled-p*))
464 (print-object object stream))
465 ((typep object 'structure-object)
466 (default-structure-print object stream *current-level-in-print*))
468 (write-string "#<INSTANCE but not STRUCTURE-OBJECT>" stream))))
470 (unless (and (funcallable-instance-p object)
471 (printed-as-funcallable-standard-class object stream))
472 (output-fun object stream)))
474 (output-symbol object stream))
478 (output-integer object stream))
480 (output-float object stream))
482 (output-ratio object stream))
484 (output-ratio object stream))
486 (output-complex object stream))))
488 (output-character object stream))
490 (output-vector object stream))
492 (output-array object stream))
494 (output-sap object stream))
496 (output-weak-pointer object stream))
498 (output-lra object stream))
500 (output-code-component object stream))
502 (output-fdefn object stream))
504 (output-random object stream))))
508 ;;; values of *PRINT-CASE* and (READTABLE-CASE *READTABLE*) the last
509 ;;; time the printer was called
510 (defvar *previous-case* nil)
511 (defvar *previous-readtable-case* nil)
513 ;;; This variable contains the current definition of one of three
514 ;;; symbol printers. SETUP-PRINTER-STATE sets this variable.
515 (defvar *internal-symbol-output-fun* nil)
517 ;;; This function sets the internal global symbol
518 ;;; *INTERNAL-SYMBOL-OUTPUT-FUN* to the right function depending on
519 ;;; the value of *PRINT-CASE*. See the manual for details. The print
520 ;;; buffer stream is also reset.
521 (defun setup-printer-state ()
522 (unless (and (eq *print-case* *previous-case*)
523 (eq (readtable-case *readtable*) *previous-readtable-case*))
524 (setq *previous-case* *print-case*)
525 (setq *previous-readtable-case* (readtable-case *readtable*))
526 (unless (member *print-case* '(:upcase :downcase :capitalize))
527 (setq *print-case* :upcase)
528 (error "invalid *PRINT-CASE* value: ~S" *previous-case*))
529 (unless (member *previous-readtable-case*
530 '(:upcase :downcase :invert :preserve))
531 (setf (readtable-case *readtable*) :upcase)
532 (error "invalid READTABLE-CASE value: ~S" *previous-readtable-case*))
534 (setq *internal-symbol-output-fun*
535 (case *previous-readtable-case*
538 (:upcase #'output-preserve-symbol)
539 (:downcase #'output-lowercase-symbol)
540 (:capitalize #'output-capitalize-symbol)))
543 (:upcase #'output-uppercase-symbol)
544 (:downcase #'output-preserve-symbol)
545 (:capitalize #'output-capitalize-symbol)))
546 (:preserve #'output-preserve-symbol)
547 (:invert #'output-invert-symbol)))))
549 ;;; Output PNAME (a symbol-name or package-name) surrounded with |'s,
550 ;;; and with any embedded |'s or \'s escaped.
551 (defun output-quoted-symbol-name (pname stream)
552 (write-char #\| stream)
553 (dotimes (index (length pname))
554 (let ((char (schar pname index)))
555 (when (or (char= char #\\) (char= char #\|))
556 (write-char #\\ stream))
557 (write-char char stream)))
558 (write-char #\| stream))
560 (defun output-symbol (object stream)
561 (if (or *print-escape* *print-readably*)
562 (let ((package (symbol-package object))
563 (name (symbol-name object)))
565 ;; The ANSI spec "22.1.3.3.1 Package Prefixes for Symbols"
566 ;; requires that keywords be printed with preceding colons
567 ;; always, regardless of the value of *PACKAGE*.
568 ((eq package *keyword-package*)
569 (write-char #\: stream))
570 ;; Otherwise, if the symbol's home package is the current
571 ;; one, then a prefix is never necessary.
572 ((eq package (sane-package)))
573 ;; Uninterned symbols print with a leading #:.
575 (when (or *print-gensym* *print-readably*)
576 (write-string "#:" stream)))
578 (multiple-value-bind (symbol accessible)
579 (find-symbol name (sane-package))
580 ;; If we can find the symbol by looking it up, it need not
581 ;; be qualified. This can happen if the symbol has been
582 ;; inherited from a package other than its home package.
583 (unless (and accessible (eq symbol object))
584 (output-symbol-name (package-name package) stream)
585 (multiple-value-bind (symbol externalp)
586 (find-external-symbol name package)
587 (declare (ignore symbol))
589 (write-char #\: stream)
590 (write-string "::" stream)))))))
591 (output-symbol-name name stream))
592 (output-symbol-name (symbol-name object) stream nil)))
594 ;;; Output the string NAME as if it were a symbol name. In other
595 ;;; words, diddle its case according to *PRINT-CASE* and
597 (defun output-symbol-name (name stream &optional (maybe-quote t))
598 (declare (type simple-string name))
599 (let ((*readtable* (if *print-readably* *standard-readtable* *readtable*)))
600 (setup-printer-state)
601 (if (and maybe-quote (symbol-quotep name))
602 (output-quoted-symbol-name name stream)
603 (funcall *internal-symbol-output-fun* name stream))))
605 ;;;; escaping symbols
607 ;;; When we print symbols we have to figure out if they need to be
608 ;;; printed with escape characters. This isn't a whole lot easier than
609 ;;; reading symbols in the first place.
611 ;;; For each character, the value of the corresponding element is a
612 ;;; fixnum with bits set corresponding to attributes that the
613 ;;; character has. At characters have at least one bit set, so we can
614 ;;; search for any character with a positive test.
615 (defvar *character-attributes*
616 (make-array 160 ; FIXME
617 :element-type '(unsigned-byte 16)
619 (declaim (type (simple-array (unsigned-byte 16) (#.160)) ; FIXME
620 *character-attributes*))
622 ;;; constants which are a bit-mask for each interesting character attribute
623 (defconstant other-attribute (ash 1 0)) ; Anything else legal.
624 (defconstant number-attribute (ash 1 1)) ; A numeric digit.
625 (defconstant uppercase-attribute (ash 1 2)) ; An uppercase letter.
626 (defconstant lowercase-attribute (ash 1 3)) ; A lowercase letter.
627 (defconstant sign-attribute (ash 1 4)) ; +-
628 (defconstant extension-attribute (ash 1 5)) ; ^_
629 (defconstant dot-attribute (ash 1 6)) ; .
630 (defconstant slash-attribute (ash 1 7)) ; /
631 (defconstant funny-attribute (ash 1 8)) ; Anything illegal.
633 (eval-when (:compile-toplevel :load-toplevel :execute)
635 ;;; LETTER-ATTRIBUTE is a local of SYMBOL-QUOTEP. It matches letters
636 ;;; that don't need to be escaped (according to READTABLE-CASE.)
637 (defparameter *attribute-names*
638 `((number . number-attribute) (lowercase . lowercase-attribute)
639 (uppercase . uppercase-attribute) (letter . letter-attribute)
640 (sign . sign-attribute) (extension . extension-attribute)
641 (dot . dot-attribute) (slash . slash-attribute)
642 (other . other-attribute) (funny . funny-attribute)))
646 (flet ((set-bit (char bit)
647 (let ((code (char-code char)))
648 (setf (aref *character-attributes* code)
649 (logior bit (aref *character-attributes* code))))))
651 (dolist (char '(#\! #\@ #\$ #\% #\& #\* #\= #\~ #\[ #\] #\{ #\}
653 (set-bit char other-attribute))
656 (set-bit (digit-char i) number-attribute))
658 (do ((code (char-code #\A) (1+ code))
659 (end (char-code #\Z)))
661 (declare (fixnum code end))
662 (set-bit (code-char code) uppercase-attribute)
663 (set-bit (char-downcase (code-char code)) lowercase-attribute))
665 (set-bit #\- sign-attribute)
666 (set-bit #\+ sign-attribute)
667 (set-bit #\^ extension-attribute)
668 (set-bit #\_ extension-attribute)
669 (set-bit #\. dot-attribute)
670 (set-bit #\/ slash-attribute)
672 ;; Mark anything not explicitly allowed as funny.
673 (dotimes (i 160) ; FIXME
674 (when (zerop (aref *character-attributes* i))
675 (setf (aref *character-attributes* i) funny-attribute))))
677 ;;; For each character, the value of the corresponding element is the
678 ;;; lowest base in which that character is a digit.
679 (defvar *digit-bases*
680 (make-array 128 ; FIXME
681 :element-type '(unsigned-byte 8)
682 :initial-element 36))
683 (declaim (type (simple-array (unsigned-byte 8) (#.128)) ; FIXME
686 (let ((char (digit-char i 36)))
687 (setf (aref *digit-bases* (char-code char)) i)))
689 ;;; A FSM-like thingie that determines whether a symbol is a potential
690 ;;; number or has evil characters in it.
691 (defun symbol-quotep (name)
692 (declare (simple-string name))
693 (macrolet ((advance (tag &optional (at-end t))
696 ,(if at-end '(go TEST-SIGN) '(return nil)))
697 (setq current (schar name index)
698 code (char-code current)
700 ((< code 160) (aref attributes code))
701 ((upper-case-p current) uppercase-attribute)
702 ((lower-case-p current) lowercase-attribute)
703 (t other-attribute)))
706 (test (&rest attributes)
718 `(and (< code 128) ; FIXME
719 (< (the fixnum (aref bases code)) base))))
721 (prog ((len (length name))
722 (attributes *character-attributes*)
723 (bases *digit-bases*)
726 (case (readtable-case *readtable*)
727 (:upcase uppercase-attribute)
728 (:downcase lowercase-attribute)
729 (t (logior lowercase-attribute uppercase-attribute))))
734 (declare (fixnum len base index bits code))
737 TEST-SIGN ; At end, see whether it is a sign...
738 (return (not (test sign)))
740 OTHER ; not potential number, see whether funny chars...
741 (let ((mask (logxor (logior lowercase-attribute uppercase-attribute
744 (do ((i (1- index) (1+ i)))
745 ((= i len) (return-from symbol-quotep nil))
746 (unless (zerop (logand (let* ((char (schar name i))
747 (code (char-code char)))
749 ((< code 160) (aref attributes code))
750 ((upper-case-p char) uppercase-attribute)
751 ((lower-case-p char) lowercase-attribute)
752 (t other-attribute)))
754 (return-from symbol-quotep t))))
759 (advance LAST-DIGIT-ALPHA)
761 (when (test letter number other slash) (advance OTHER nil))
762 (when (char= current #\.) (advance DOT-FOUND))
763 (when (test sign extension) (advance START-STUFF nil))
766 DOT-FOUND ; leading dots...
767 (when (test letter) (advance START-DOT-MARKER nil))
768 (when (digitp) (advance DOT-DIGIT))
769 (when (test number other) (advance OTHER nil))
770 (when (test extension slash sign) (advance START-DOT-STUFF nil))
771 (when (char= current #\.) (advance DOT-FOUND))
774 START-STUFF ; leading stuff before any dot or digit
777 (advance LAST-DIGIT-ALPHA)
779 (when (test number other) (advance OTHER nil))
780 (when (test letter) (advance START-MARKER nil))
781 (when (char= current #\.) (advance START-DOT-STUFF nil))
782 (when (test sign extension slash) (advance START-STUFF nil))
785 START-MARKER ; number marker in leading stuff...
786 (when (test letter) (advance OTHER nil))
789 START-DOT-STUFF ; leading stuff containing dot without digit...
790 (when (test letter) (advance START-DOT-STUFF nil))
791 (when (digitp) (advance DOT-DIGIT))
792 (when (test sign extension dot slash) (advance START-DOT-STUFF nil))
793 (when (test number other) (advance OTHER nil))
796 START-DOT-MARKER ; number marker in leading stuff with dot..
797 ;; leading stuff containing dot without digit followed by letter...
798 (when (test letter) (advance OTHER nil))
801 DOT-DIGIT ; in a thing with dots...
802 (when (test letter) (advance DOT-MARKER))
803 (when (digitp) (advance DOT-DIGIT))
804 (when (test number other) (advance OTHER nil))
805 (when (test sign extension dot slash) (advance DOT-DIGIT))
808 DOT-MARKER ; number marker in number with dot...
809 (when (test letter) (advance OTHER nil))
812 LAST-DIGIT-ALPHA ; previous char is a letter digit...
813 (when (or (digitp) (test sign slash))
814 (advance ALPHA-DIGIT))
815 (when (test letter number other dot) (advance OTHER nil))
818 ALPHA-DIGIT ; seen a digit which is a letter...
819 (when (or (digitp) (test sign slash))
821 (advance LAST-DIGIT-ALPHA)
822 (advance ALPHA-DIGIT)))
823 (when (test letter) (advance ALPHA-MARKER))
824 (when (test number other dot) (advance OTHER nil))
827 ALPHA-MARKER ; number marker in number with alpha digit...
828 (when (test letter) (advance OTHER nil))
831 DIGIT ; seen only ordinary (non-alphabetic) numeric digits...
834 (advance ALPHA-DIGIT)
836 (when (test number other) (advance OTHER nil))
837 (when (test letter) (advance MARKER))
838 (when (test extension slash sign) (advance DIGIT))
839 (when (char= current #\.) (advance DOT-DIGIT))
842 MARKER ; number marker in a numeric number...
843 ;; ("What," you may ask, "is a 'number marker'?" It's something
844 ;; that a conforming implementation might use in number syntax.
845 ;; See ANSI 2.3.1.1 "Potential Numbers as Tokens".)
846 (when (test letter) (advance OTHER nil))
849 ;;;; *INTERNAL-SYMBOL-OUTPUT-FUN*
851 ;;;; case hackery: These functions are stored in
852 ;;;; *INTERNAL-SYMBOL-OUTPUT-FUN* according to the values of
853 ;;;; *PRINT-CASE* and READTABLE-CASE.
856 ;;; READTABLE-CASE *PRINT-CASE*
858 ;;; :DOWNCASE :DOWNCASE
860 (defun output-preserve-symbol (pname stream)
861 (declare (simple-string pname))
862 (write-string pname stream))
865 ;;; READTABLE-CASE *PRINT-CASE*
866 ;;; :UPCASE :DOWNCASE
867 (defun output-lowercase-symbol (pname stream)
868 (declare (simple-string pname))
869 (dotimes (index (length pname))
870 (let ((char (schar pname index)))
871 (write-char (char-downcase char) stream))))
874 ;;; READTABLE-CASE *PRINT-CASE*
875 ;;; :DOWNCASE :UPCASE
876 (defun output-uppercase-symbol (pname stream)
877 (declare (simple-string pname))
878 (dotimes (index (length pname))
879 (let ((char (schar pname index)))
880 (write-char (char-upcase char) stream))))
883 ;;; READTABLE-CASE *PRINT-CASE*
884 ;;; :UPCASE :CAPITALIZE
885 ;;; :DOWNCASE :CAPITALIZE
886 (defun output-capitalize-symbol (pname stream)
887 (declare (simple-string pname))
888 (let ((prev-not-alphanum t)
889 (up (eq (readtable-case *readtable*) :upcase)))
890 (dotimes (i (length pname))
891 (let ((char (char pname i)))
893 (if (or prev-not-alphanum (lower-case-p char))
895 (char-downcase char))
896 (if prev-not-alphanum
900 (setq prev-not-alphanum (not (alphanumericp char)))))))
903 ;;; READTABLE-CASE *PRINT-CASE*
905 (defun output-invert-symbol (pname stream)
906 (declare (simple-string pname))
909 (dotimes (i (length pname))
910 (let ((ch (schar pname i)))
911 (when (both-case-p ch)
912 (if (upper-case-p ch)
914 (setq all-upper nil)))))
915 (cond (all-upper (output-lowercase-symbol pname stream))
916 (all-lower (output-uppercase-symbol pname stream))
918 (write-string pname stream)))))
922 (let ((*readtable* (copy-readtable nil)))
923 (format t "READTABLE-CASE Input Symbol-name~@
924 ----------------------------------~%")
925 (dolist (readtable-case '(:upcase :downcase :preserve :invert))
926 (setf (readtable-case *readtable*) readtable-case)
927 (dolist (input '("ZEBRA" "Zebra" "zebra"))
928 (format t "~&:~A~16T~A~24T~A"
929 (string-upcase readtable-case)
931 (symbol-name (read-from-string input)))))))
934 (let ((*readtable* (copy-readtable nil)))
935 (format t "READTABLE-CASE *PRINT-CASE* Symbol-name Output Princ~@
936 --------------------------------------------------------~%")
937 (dolist (readtable-case '(:upcase :downcase :preserve :invert))
938 (setf (readtable-case *readtable*) readtable-case)
939 (dolist (*print-case* '(:upcase :downcase :capitalize))
940 (dolist (symbol '(|ZEBRA| |Zebra| |zebra|))
941 (format t "~&:~A~15T:~A~29T~A~42T~A~50T~A"
942 (string-upcase readtable-case)
943 (string-upcase *print-case*)
945 (prin1-to-string symbol)
946 (princ-to-string symbol)))))))
949 ;;;; recursive objects
951 (defun output-list (list stream)
952 (descend-into (stream)
953 (write-char #\( stream)
957 (punt-print-if-too-long length stream)
958 (output-object (pop list) stream)
961 (when (or (atom list)
962 (check-for-circularity list))
963 (write-string " . " stream)
964 (output-object list stream)
966 (write-char #\space stream)
968 (write-char #\) stream)))
970 (defun output-vector (vector stream)
971 (declare (vector vector))
972 (cond ((stringp vector)
973 (cond ((and *print-readably*
974 (not (eq (array-element-type vector)
977 (make-array 0 :element-type 'character))))))
978 (error 'print-not-readable :object vector))
979 ((or *print-escape* *print-readably*)
980 (write-char #\" stream)
981 (quote-string vector stream)
982 (write-char #\" stream))
984 (write-string vector stream))))
985 ((not (or *print-array* *print-readably*))
986 (output-terse-array vector stream))
987 ((bit-vector-p vector)
988 (write-string "#*" stream)
989 (dovector (bit vector)
990 ;; (Don't use OUTPUT-OBJECT here, since this code
991 ;; has to work for all possible *PRINT-BASE* values.)
992 (write-char (if (zerop bit) #\0 #\1) stream)))
994 (when (and *print-readably*
995 (not (array-readably-printable-p vector)))
996 (error 'print-not-readable :object vector))
997 (descend-into (stream)
998 (write-string "#(" stream)
999 (dotimes (i (length vector))
1001 (write-char #\space stream))
1002 (punt-print-if-too-long i stream)
1003 (output-object (aref vector i) stream))
1004 (write-string ")" stream)))))
1006 ;;; This function outputs a string quoting characters sufficiently
1007 ;;; so that someone can read it in again. Basically, put a slash in
1008 ;;; front of an character satisfying NEEDS-SLASH-P.
1009 (defun quote-string (string stream)
1010 (macrolet ((needs-slash-p (char)
1011 ;; KLUDGE: We probably should look at the readtable, but just do
1012 ;; this for now. [noted by anonymous long ago] -- WHN 19991130
1013 `(or (char= ,char #\\)
1014 (char= ,char #\"))))
1015 (with-array-data ((data string) (start) (end (length string)))
1016 (do ((index start (1+ index)))
1018 (let ((char (schar data index)))
1019 (when (needs-slash-p char) (write-char #\\ stream))
1020 (write-char char stream))))))
1022 (defun array-readably-printable-p (array)
1023 (and (eq (array-element-type array) t)
1024 (let ((zero (position 0 (array-dimensions array)))
1025 (number (position 0 (array-dimensions array)
1026 :test (complement #'eql)
1028 (or (null zero) (null number) (> zero number)))))
1030 ;;; Output the printed representation of any array in either the #< or #A
1032 (defun output-array (array stream)
1033 (if (or *print-array* *print-readably*)
1034 (output-array-guts array stream)
1035 (output-terse-array array stream)))
1037 ;;; Output the abbreviated #< form of an array.
1038 (defun output-terse-array (array stream)
1039 (let ((*print-level* nil)
1040 (*print-length* nil))
1041 (print-unreadable-object (array stream :type t :identity t))))
1043 ;;; Output the readable #A form of an array.
1044 (defun output-array-guts (array stream)
1045 (when (and *print-readably*
1046 (not (array-readably-printable-p array)))
1047 (error 'print-not-readable :object array))
1048 (write-char #\# stream)
1049 (let ((*print-base* 10)
1050 (*print-radix* nil))
1051 (output-integer (array-rank array) stream))
1052 (write-char #\A stream)
1053 (with-array-data ((data array) (start) (end))
1054 (declare (ignore end))
1055 (sub-output-array-guts data (array-dimensions array) stream start)))
1057 (defun sub-output-array-guts (array dimensions stream index)
1058 (declare (type (simple-array * (*)) array) (fixnum index))
1059 (cond ((null dimensions)
1060 (output-object (aref array index) stream))
1062 (descend-into (stream)
1063 (write-char #\( stream)
1064 (let* ((dimension (car dimensions))
1065 (dimensions (cdr dimensions))
1066 (count (reduce #'* dimensions)))
1067 (dotimes (i dimension)
1069 (write-char #\space stream))
1070 (punt-print-if-too-long i stream)
1071 (sub-output-array-guts array dimensions stream index)
1072 (incf index count)))
1073 (write-char #\) stream)))))
1075 ;;; a trivial non-generic-function placeholder for PRINT-OBJECT, for
1076 ;;; use until CLOS is set up (at which time it will be replaced with
1077 ;;; the real generic function implementation)
1078 (defun print-object (instance stream)
1079 (default-structure-print instance stream *current-level-in-print*))
1081 ;;;; integer, ratio, and complex printing (i.e. everything but floats)
1083 (defun %output-radix (base stream)
1084 (write-char #\# stream)
1085 (write-char (case base
1089 (t (%output-fixnum-in-base base 10 stream)
1093 (defun %output-fixnum-in-base (n base stream)
1094 (multiple-value-bind (q r)
1096 ;; Recurse until you have all the digits pushed on
1099 (%output-fixnum-in-base q base stream))
1100 ;; Then as each recursive call unwinds, turn the
1101 ;; digit (in remainder) into a character and output
1104 (schar "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" r)
1107 (defun %output-bignum-in-base (n base stream)
1108 (labels ((bisect (n power)
1110 (%output-fixnum-in-base n base stream)
1111 (let ((k (truncate power 2)))
1112 (multiple-value-bind (q r) (truncate n (expt base k))
1113 (bisect q (- power k))
1114 (let ((npower (if (zerop r) 0 (truncate (log r base)))))
1115 (dotimes (z (- k npower 1))
1116 (write-char #\0 stream))
1117 (bisect r npower)))))))
1118 (bisect n (truncate (log n base)))))
1120 (defun %output-integer-in-base (integer base stream)
1121 (when (minusp integer)
1122 (write-char #\- stream)
1123 (setf integer (- integer)))
1124 (if (fixnump integer)
1125 (%output-fixnum-in-base integer base stream)
1126 (%output-bignum-in-base integer base stream)))
1128 (defun output-integer (integer stream)
1129 (let ((base *print-base*))
1130 (when (and (/= base 10) *print-radix*)
1131 (%output-radix base stream))
1132 (%output-integer-in-base integer base stream)
1133 (when (and *print-radix* (= base 10))
1134 (write-char #\. stream))))
1136 (defun output-ratio (ratio stream)
1137 (let ((base *print-base*))
1139 (%output-radix base stream))
1140 (%output-integer-in-base (numerator ratio) base stream)
1141 (write-char #\/ stream)
1142 (%output-integer-in-base (denominator ratio) base stream)))
1144 (defun output-complex (complex stream)
1145 (write-string "#C(" stream)
1146 ;; FIXME: Could this just be OUTPUT-NUMBER?
1147 (output-object (realpart complex) stream)
1148 (write-char #\space stream)
1149 (output-object (imagpart complex) stream)
1150 (write-char #\) stream))
1154 ;;; FLONUM-TO-STRING (and its subsidiary function FLOAT-STRING) does
1155 ;;; most of the work for all printing of floating point numbers in
1156 ;;; FORMAT. It converts a floating point number to a string in a free
1157 ;;; or fixed format with no exponent. The interpretation of the
1158 ;;; arguments is as follows:
1160 ;;; X - The floating point number to convert, which must not be
1162 ;;; WIDTH - The preferred field width, used to determine the number
1163 ;;; of fraction digits to produce if the FDIGITS parameter
1164 ;;; is unspecified or NIL. If the non-fraction digits and the
1165 ;;; decimal point alone exceed this width, no fraction digits
1166 ;;; will be produced unless a non-NIL value of FDIGITS has been
1167 ;;; specified. Field overflow is not considerd an error at this
1169 ;;; FDIGITS - The number of fractional digits to produce. Insignificant
1170 ;;; trailing zeroes may be introduced as needed. May be
1171 ;;; unspecified or NIL, in which case as many digits as possible
1172 ;;; are generated, subject to the constraint that there are no
1173 ;;; trailing zeroes.
1174 ;;; SCALE - If this parameter is specified or non-NIL, then the number
1175 ;;; printed is (* x (expt 10 scale)). This scaling is exact,
1176 ;;; and cannot lose precision.
1177 ;;; FMIN - This parameter, if specified or non-NIL, is the minimum
1178 ;;; number of fraction digits which will be produced, regardless
1179 ;;; of the value of WIDTH or FDIGITS. This feature is used by
1180 ;;; the ~E format directive to prevent complete loss of
1181 ;;; significance in the printed value due to a bogus choice of
1185 ;;; (VALUES DIGIT-STRING DIGIT-LENGTH LEADING-POINT TRAILING-POINT DECPNT)
1186 ;;; where the results have the following interpretation:
1188 ;;; DIGIT-STRING - The decimal representation of X, with decimal point.
1189 ;;; DIGIT-LENGTH - The length of the string DIGIT-STRING.
1190 ;;; LEADING-POINT - True if the first character of DIGIT-STRING is the
1192 ;;; TRAILING-POINT - True if the last character of DIGIT-STRING is the
1194 ;;; POINT-POS - The position of the digit preceding the decimal
1195 ;;; point. Zero indicates point before first digit.
1197 ;;; NOTE: FLONUM-TO-STRING goes to a lot of trouble to guarantee
1198 ;;; accuracy. Specifically, the decimal number printed is the closest
1199 ;;; possible approximation to the true value of the binary number to
1200 ;;; be printed from among all decimal representations with the same
1201 ;;; number of digits. In free-format output, i.e. with the number of
1202 ;;; digits unconstrained, it is guaranteed that all the information is
1203 ;;; preserved, so that a properly- rounding reader can reconstruct the
1204 ;;; original binary number, bit-for-bit, from its printed decimal
1205 ;;; representation. Furthermore, only as many digits as necessary to
1206 ;;; satisfy this condition will be printed.
1208 ;;; FLOAT-DIGITS actually generates the digits for positive numbers;
1209 ;;; see below for comments.
1211 (defun flonum-to-string (x &optional width fdigits scale fmin)
1212 (declare (type float x))
1213 ;; FIXME: I think only FORMAT-DOLLARS calls FLONUM-TO-STRING with
1214 ;; possibly-negative X.
1217 ;; Zero is a special case which FLOAT-STRING cannot handle.
1219 (let ((s (make-string (1+ fdigits) :initial-element #\0)))
1220 (setf (schar s 0) #\.)
1221 (values s (length s) t (zerop fdigits) 0))
1222 (values "." 1 t t 0)))
1224 (multiple-value-bind (e string)
1226 (flonum-to-digits x (min (- fdigits) (- (or fmin 0))))
1227 (if (and width (> width 1))
1228 (let ((w (multiple-value-list (flonum-to-digits x (1- width) t)))
1229 (f (multiple-value-list (flonum-to-digits x (- (or fmin 0))))))
1231 ((>= (length (cadr w)) (length (cadr f)))
1233 (t (values-list f))))
1234 (flonum-to-digits x)))
1235 (let ((e (+ e (or scale 0)))
1236 (stream (make-string-output-stream)))
1239 (write-string string stream :end (min (length string) e))
1240 (dotimes (i (- e (length string)))
1241 (write-char #\0 stream))
1242 (write-char #\. stream)
1243 (write-string string stream :start (min (length string) e))
1245 (dotimes (i (- fdigits
1247 (min (length string) e))))
1248 (write-char #\0 stream))))
1250 (write-string "." stream)
1252 (write-char #\0 stream))
1253 (write-string string stream)
1255 (dotimes (i (+ fdigits e (- (length string))))
1256 (write-char #\0 stream)))))
1257 (let ((string (get-output-stream-string stream)))
1258 (values string (length string)
1259 (char= (char string 0) #\.)
1260 (char= (char string (1- (length string))) #\.)
1261 (position #\. string))))))))
1263 ;;; implementation of figure 1 from Burger and Dybvig, 1996. As the
1264 ;;; implementation of the Dragon from Classic CMUCL (and previously in
1265 ;;; SBCL above FLONUM-TO-STRING) says: "DO NOT EVEN THINK OF
1266 ;;; ATTEMPTING TO UNDERSTAND THIS CODE WITHOUT READING THE PAPER!",
1267 ;;; and in this case we have to add that even reading the paper might
1268 ;;; not bring immediate illumination as CSR has attempted to turn
1269 ;;; idiomatic Scheme into idiomatic Lisp.
1271 ;;; FIXME: figure 1 from Burger and Dybvig is the unoptimized
1272 ;;; algorithm, noticeably slow at finding the exponent. Figure 2 has
1273 ;;; an improved algorithm, but CSR ran out of energy.
1275 ;;; possible extension for the enthusiastic: printing floats in bases
1276 ;;; other than base 10.
1277 (defconstant single-float-min-e
1278 (nth-value 1 (decode-float least-positive-single-float)))
1279 (defconstant double-float-min-e
1280 (nth-value 1 (decode-float least-positive-double-float)))
1282 (defconstant long-float-min-e
1283 (nth-value 1 (decode-float least-positive-long-float)))
1285 (defun flonum-to-digits (v &optional position relativep)
1286 (let ((print-base 10) ; B
1288 (float-digits (float-digits v)) ; p
1289 (digit-characters "0123456789")
1292 (single-float single-float-min-e)
1293 (double-float double-float-min-e)
1295 (long-float long-float-min-e))))
1296 (multiple-value-bind (f e)
1297 (integer-decode-float v)
1298 (let (;; FIXME: these even tests assume normal IEEE rounding
1299 ;; mode. I wonder if we should cater for non-normal?
1302 (result (make-array 50 :element-type 'base-char
1303 :fill-pointer 0 :adjustable t)))
1304 (labels ((scale (r s m+ m-)
1306 (s s (* s print-base)))
1307 ((not (or (> (+ r m+) s)
1308 (and high-ok (= (+ r m+) s))))
1310 (r r (* r print-base))
1311 (m+ m+ (* m+ print-base))
1312 (m- m- (* m- print-base)))
1313 ((not (or (< (* (+ r m+) print-base) s)
1315 (= (* (+ r m+) print-base) s))))
1316 (values k (generate r s m+ m-)))))))
1317 (generate (r s m+ m-)
1321 (setf (values d r) (truncate (* r print-base) s))
1322 (setf m+ (* m+ print-base))
1323 (setf m- (* m- print-base))
1324 (setf tc1 (or (< r m-) (and low-ok (= r m-))))
1325 (setf tc2 (or (> (+ r m+) s)
1326 (and high-ok (= (+ r m+) s))))
1329 (vector-push-extend (char digit-characters d) result)
1333 ((and (not tc1) tc2) (1+ d))
1334 ((and tc1 (not tc2)) d)
1336 (if (< (* r 2) s) d (1+ d))))))
1337 (vector-push-extend (char digit-characters d) result)
1338 (return-from generate result)))))
1342 (let* ((be (expt float-radix e))
1343 (be1 (* be float-radix)))
1344 (if (/= f (expt float-radix (1- float-digits)))
1354 (/= f (expt float-radix (1- float-digits))))
1356 s (* (expt float-radix (- e)) 2)
1359 (setf r (* f float-radix 2)
1360 s (* (expt float-radix (- 1 e)) 2)
1365 (aver (> position 0))
1367 ;; running out of letters here
1368 (l 1 (* l print-base)))
1369 ((>= (* s l) (+ r m+))
1371 (if (< (+ r (* s (/ (expt print-base (- k position)) 2)))
1372 (* s (expt print-base k)))
1373 (setf position (- k position))
1374 (setf position (- k position 1))))))
1375 (let ((low (max m- (/ (* s (expt print-base position)) 2)))
1376 (high (max m+ (/ (* s (expt print-base position)) 2))))
1383 (values r s m+ m-))))
1384 (multiple-value-bind (r s m+ m-) (initialize)
1385 (scale r s m+ m-)))))))
1387 ;;; Given a non-negative floating point number, SCALE-EXPONENT returns
1388 ;;; a new floating point number Z in the range (0.1, 1.0] and an
1389 ;;; exponent E such that Z * 10^E is (approximately) equal to the
1390 ;;; original number. There may be some loss of precision due the
1391 ;;; floating point representation. The scaling is always done with
1392 ;;; long float arithmetic, which helps printing of lesser precisions
1393 ;;; as well as avoiding generic arithmetic.
1395 ;;; When computing our initial scale factor using EXPT, we pull out
1396 ;;; part of the computation to avoid over/under flow. When
1397 ;;; denormalized, we must pull out a large factor, since there is more
1398 ;;; negative exponent range than positive range.
1400 (eval-when (:compile-toplevel :execute)
1401 (setf *read-default-float-format*
1402 #!+long-float 'long-float #!-long-float 'double-float))
1403 (defun scale-exponent (original-x)
1404 (let* ((x (coerce original-x 'long-float)))
1405 (multiple-value-bind (sig exponent) (decode-float x)
1406 (declare (ignore sig))
1408 (values (float 0.0e0 original-x) 1)
1409 (let* ((ex (locally (declare (optimize (safety 0)))
1411 (round (* exponent (log 2e0 10))))))
1413 (if (float-denormalized-p x)
1415 (* x 1.0e16 (expt 10.0e0 (- (- ex) 16)))
1417 (* x 1.0e18 (expt 10.0e0 (- (- ex) 18)))
1418 (* x 10.0e0 (expt 10.0e0 (- (- ex) 1))))
1419 (/ x 10.0e0 (expt 10.0e0 (1- ex))))))
1420 (do ((d 10.0e0 (* d 10.0e0))
1424 (do ((m 10.0e0 (* m 10.0e0))
1428 (values (float z original-x) ex))
1429 (declare (long-float m) (integer ex))))
1430 (declare (long-float d))))))))
1431 (eval-when (:compile-toplevel :execute)
1432 (setf *read-default-float-format* 'single-float))
1434 ;;;; entry point for the float printer
1436 ;;; the float printer as called by PRINT, PRIN1, PRINC, etc. The
1437 ;;; argument is printed free-format, in either exponential or
1438 ;;; non-exponential notation, depending on its magnitude.
1440 ;;; NOTE: When a number is to be printed in exponential format, it is
1441 ;;; scaled in floating point. Since precision may be lost in this
1442 ;;; process, the guaranteed accuracy properties of FLONUM-TO-STRING
1443 ;;; are lost. The difficulty is that FLONUM-TO-STRING performs
1444 ;;; extensive computations with integers of similar magnitude to that
1445 ;;; of the number being printed. For large exponents, the bignums
1446 ;;; really get out of hand. If bignum arithmetic becomes reasonably
1447 ;;; fast and the exponent range is not too large, then it might become
1448 ;;; attractive to handle exponential notation with the same accuracy
1449 ;;; as non-exponential notation, using the method described in the
1450 ;;; Steele and White paper.
1452 ;;; NOTE II: this has been bypassed slightly by implementing Burger
1453 ;;; and Dybvig, 1996. When someone has time (KLUDGE) they can
1454 ;;; probably (a) implement the optimizations suggested by Burger and
1455 ;;; Dyvbig, and (b) remove all vestiges of Dragon4, including from
1456 ;;; fixed-format printing.
1458 ;;; Print the appropriate exponent marker for X and the specified exponent.
1459 (defun print-float-exponent (x exp stream)
1460 (declare (type float x) (type integer exp) (type stream stream))
1461 (let ((*print-radix* nil)
1462 (plusp (plusp exp)))
1463 (if (typep x *read-default-float-format*)
1465 (format stream "e~:[~;+~]~D" plusp exp))
1466 (format stream "~C~:[~;+~]~D"
1474 (defun output-float-infinity (x stream)
1475 (declare (float x) (stream stream))
1477 (write-string "#." stream))
1479 (error 'print-not-readable :object x))
1481 (write-string "#<" stream)))
1482 (write-string "SB-EXT:" stream)
1483 (write-string (symbol-name (float-format-name x)) stream)
1484 (write-string (if (plusp x) "-POSITIVE-" "-NEGATIVE-")
1486 (write-string "INFINITY" stream)
1488 (write-string ">" stream)))
1490 (defun output-float-nan (x stream)
1491 (print-unreadable-object (x stream)
1492 (princ (float-format-name x) stream)
1493 (write-string (if (float-trapping-nan-p x) " trapping" " quiet") stream)
1494 (write-string " NaN" stream)))
1496 ;;; the function called by OUTPUT-OBJECT to handle floats
1497 (defun output-float (x stream)
1499 ((float-infinity-p x)
1500 (output-float-infinity x stream))
1502 (output-float-nan x stream))
1504 (let ((x (cond ((minusp (float-sign x))
1505 (write-char #\- stream)
1511 (write-string "0.0" stream)
1512 (print-float-exponent x 0 stream))
1514 (output-float-aux x stream -3 8)))))))
1515 (defun output-float-aux (x stream e-min e-max)
1516 (multiple-value-bind (e string)
1517 (flonum-to-digits x)
1522 (write-string string stream :end (min (length string) e))
1523 (dotimes (i (- e (length string)))
1524 (write-char #\0 stream))
1525 (write-char #\. stream)
1526 (write-string string stream :start (min (length string) e))
1527 (when (<= (length string) e)
1528 (write-char #\0 stream))
1529 (print-float-exponent x 0 stream))
1531 (write-string "0." stream)
1533 (write-char #\0 stream))
1534 (write-string string stream)
1535 (print-float-exponent x 0 stream))))
1536 (t (write-string string stream :end 1)
1537 (write-char #\. stream)
1538 (write-string string stream :start 1)
1539 (when (= (length string) 1)
1540 (write-char #\0 stream))
1541 (print-float-exponent x (1- e) stream)))))
1543 ;;;; other leaf objects
1545 ;;; If *PRINT-ESCAPE* is false, just do a WRITE-CHAR, otherwise output
1546 ;;; the character name or the character in the #\char format.
1547 (defun output-character (char stream)
1548 (if (or *print-escape* *print-readably*)
1549 (let ((graphicp (graphic-char-p char))
1550 (name (char-name char)))
1551 (write-string "#\\" stream)
1552 (if (and name (not graphicp))
1553 (quote-string name stream)
1554 (write-char char stream)))
1555 (write-char char stream)))
1557 (defun output-sap (sap stream)
1558 (declare (type system-area-pointer sap))
1560 (format stream "#.(~S #X~8,'0X)" 'int-sap (sap-int sap)))
1562 (print-unreadable-object (sap stream)
1563 (format stream "system area pointer: #X~8,'0X" (sap-int sap))))))
1565 (defun output-weak-pointer (weak-pointer stream)
1566 (declare (type weak-pointer weak-pointer))
1567 (print-unreadable-object (weak-pointer stream)
1568 (multiple-value-bind (value validp) (weak-pointer-value weak-pointer)
1570 (write-string "weak pointer: " stream)
1571 (write value :stream stream))
1573 (write-string "broken weak pointer" stream))))))
1575 (defun output-code-component (component stream)
1576 (print-unreadable-object (component stream :identity t)
1577 (let ((dinfo (%code-debug-info component)))
1578 (cond ((eq dinfo :bogus-lra)
1579 (write-string "bogus code object" stream))
1581 (write-string "code object" stream)
1583 (write-char #\space stream)
1584 (output-object (sb!c::debug-info-name dinfo) stream)))))))
1586 (defun output-lra (lra stream)
1587 (print-unreadable-object (lra stream :identity t)
1588 (write-string "return PC object" stream)))
1590 (defun output-fdefn (fdefn stream)
1591 (print-unreadable-object (fdefn stream)
1592 (write-string "FDEFINITION object for " stream)
1593 (output-object (fdefn-name fdefn) stream)))
1597 ;;; Output OBJECT as using PRINT-OBJECT if it's a
1598 ;;; FUNCALLABLE-STANDARD-CLASS, or return NIL otherwise.
1600 ;;; The definition here is a simple temporary placeholder. It will be
1601 ;;; overwritten by a smarter version (capable of calling generic
1602 ;;; PRINT-OBJECT when appropriate) when CLOS is installed.
1603 (defun printed-as-clos-funcallable-standard-class (object stream)
1604 (declare (ignore object stream))
1607 (defun output-fun (object stream)
1608 (let* ((*print-length* 3) ; in case we have to..
1609 (*print-level* 3) ; ..print an interpreted function definition
1610 ;; FIXME: This find-the-function-name idiom ought to be
1611 ;; encapsulated in a function somewhere.
1612 (name (case (fun-subtype object)
1613 (#.sb!vm:closure-header-widetag "CLOSURE")
1614 (#.sb!vm:simple-fun-header-widetag (%simple-fun-name object))
1615 (t 'no-name-available)))
1616 (identified-by-name-p (and (symbolp name)
1618 (eq (fdefinition name) object))))
1619 (print-unreadable-object (object
1621 :identity (not identified-by-name-p))
1622 (prin1 'function stream)
1623 (unless (eq name 'no-name-available)
1624 (format stream " ~S" name)))))
1626 ;;;; catch-all for unknown things
1628 (defun output-random (object stream)
1629 (print-unreadable-object (object stream :identity t)
1630 (let ((lowtag (lowtag-of object)))
1632 (#.sb!vm:other-pointer-lowtag
1633 (let ((widetag (widetag-of object)))
1635 (#.sb!vm:value-cell-header-widetag
1636 (write-string "value cell " stream)
1637 (output-object (value-cell-ref object) stream))
1639 (write-string "unknown pointer object, widetag=" stream)
1640 (let ((*print-base* 16) (*print-radix* t))
1641 (output-integer widetag stream))))))
1642 ((#.sb!vm:fun-pointer-lowtag
1643 #.sb!vm:instance-pointer-lowtag
1644 #.sb!vm:list-pointer-lowtag)
1645 (write-string "unknown pointer object, lowtag=" stream)
1646 (let ((*print-base* 16) (*print-radix* t))
1647 (output-integer lowtag stream)))
1649 (case (widetag-of object)
1650 (#.sb!vm:unbound-marker-widetag
1651 (write-string "unbound marker" stream))
1653 (write-string "unknown immediate object, lowtag=" stream)
1654 (let ((*print-base* 2) (*print-radix* t))
1655 (output-integer lowtag stream))
1656 (write-string ", widetag=" stream)
1657 (let ((*print-base* 16) (*print-radix* t))
1658 (output-integer (widetag-of object) stream)))))))))