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 "Flag which indicates that slashification is on. See the manual")
27 (defvar *print-pretty* nil ; (set later when pretty-printer is initialized)
29 "Flag which indicates that pretty printing is to be used")
30 (defvar *print-base* 10.
32 "The output base for integers and rationals.")
33 (defvar *print-radix* nil
35 "This flag requests to verify base when printing rationals.")
36 (defvar *print-level* nil
38 "How many levels deep to print. Unlimited if null.")
39 (defvar *print-length* nil
41 "How many elements to print on each level. Unlimited if null.")
42 (defvar *print-circle* nil
44 "Whether to worry about circular list structures. See the manual.")
45 (defvar *print-case* :upcase
47 "What kind of case the printer should use by default")
48 (defvar *print-array* t
50 "Whether the array should print its guts out")
51 (defvar *print-gensym* t
53 "If true, symbols with no home package are printed with a #: prefix.
54 If false, no prefix is printed.")
55 (defvar *print-lines* nil
57 "The maximum number of lines to print. If NIL, unlimited.")
58 (defvar *print-right-margin* nil
60 "The position of the right margin in ems. If NIL, try to determine this
61 from the stream in use.")
62 (defvar *print-miser-width* nil
64 "If the remaining space between the current column and the right margin
65 is less than this, then print using ``miser-style'' output. Miser
66 style conditional newlines are turned on, and all indentations are
67 turned off. If NIL, never use miser mode.")
68 (defvar *print-pprint-dispatch* nil
70 "The pprint-dispatch-table that controls how to pretty print objects. See
71 COPY-PPRINT-DISPATH, PPRINT-DISPATCH, and SET-PPRINT-DISPATCH.")
73 (defmacro with-standard-io-syntax (&body body)
75 "Bind the reader and printer control variables to values that enable READ
76 to reliably read the results of PRINT. These values are:
77 *PACKAGE* the COMMON-LISP-USER package
87 *PRINT-MISER-WIDTH* NIL
91 *PRINT-RIGHT-MARGIN* NIL
93 *READ-DEFAULT-FLOAT-FORMAT* SINGLE-FLOAT
96 *READTABLE* the standard readtable."
97 `(%with-standard-io-syntax #'(lambda () ,@body)))
99 (defun %with-standard-io-syntax (function)
100 (let ((*package* (find-package "COMMON-LISP-USER"))
103 (*print-case* :upcase)
110 (*print-miser-width* nil)
114 (*print-right-margin* nil)
116 (*read-default-float-format* 'single-float)
118 (*read-suppress* nil)
119 ;; FIXME: It doesn't seem like a good idea to expose our
120 ;; disaster-recovery *STANDARD-READTABLE* here. What if some
121 ;; enterprising user corrupts the disaster-recovery readtable
122 ;; by doing destructive readtable operations within
123 ;; WITH-STANDARD-IO-SYNTAX? Perhaps we should do a
124 ;; COPY-READTABLE? The consing would be unfortunate, though.
125 (*readtable* *standard-readtable*))
128 ;;;; routines to print objects
130 (defun write (object &key
131 ((:stream stream) *standard-output*)
132 ((:escape *print-escape*) *print-escape*)
133 ((:radix *print-radix*) *print-radix*)
134 ((:base *print-base*) *print-base*)
135 ((:circle *print-circle*) *print-circle*)
136 ((:pretty *print-pretty*) *print-pretty*)
137 ((:level *print-level*) *print-level*)
138 ((:length *print-length*) *print-length*)
139 ((:case *print-case*) *print-case*)
140 ((:array *print-array*) *print-array*)
141 ((:gensym *print-gensym*) *print-gensym*)
142 ((:readably *print-readably*) *print-readably*)
143 ((:right-margin *print-right-margin*)
144 *print-right-margin*)
145 ((:miser-width *print-miser-width*)
147 ((:lines *print-lines*) *print-lines*)
148 ((:pprint-dispatch *print-pprint-dispatch*)
149 *print-pprint-dispatch*))
151 "Outputs OBJECT to the specified stream, defaulting to *STANDARD-OUTPUT*"
152 (output-object object (out-synonym-of stream))
155 (defun prin1 (object &optional stream)
157 "Outputs a mostly READable printed representation of OBJECT on the specified
159 (let ((*print-escape* T))
160 (output-object object (out-synonym-of stream)))
163 (defun princ (object &optional stream)
165 "Outputs an aesthetic but not necessarily READable printed representation
166 of OBJECT on the specified STREAM."
167 (let ((*print-escape* NIL)
168 (*print-readably* NIL))
169 (output-object object (out-synonym-of stream)))
172 (defun print (object &optional stream)
174 "Outputs a terpri, the mostly READable printed represenation of OBJECT, and
175 space to the specified STREAM."
176 (let ((stream (out-synonym-of stream)))
178 (prin1 object stream)
179 (write-char #\space stream)
182 (defun pprint (object &optional stream)
184 "Prettily outputs OBJECT preceded by a newline."
185 (let ((*print-pretty* t)
187 (stream (out-synonym-of stream)))
189 (output-object object stream))
192 (defun write-to-string
194 ((:escape *print-escape*) *print-escape*)
195 ((:radix *print-radix*) *print-radix*)
196 ((:base *print-base*) *print-base*)
197 ((:circle *print-circle*) *print-circle*)
198 ((:pretty *print-pretty*) *print-pretty*)
199 ((:level *print-level*) *print-level*)
200 ((:length *print-length*) *print-length*)
201 ((:case *print-case*) *print-case*)
202 ((:array *print-array*) *print-array*)
203 ((:gensym *print-gensym*) *print-gensym*)
204 ((:readably *print-readably*) *print-readably*)
205 ((:right-margin *print-right-margin*) *print-right-margin*)
206 ((:miser-width *print-miser-width*) *print-miser-width*)
207 ((:lines *print-lines*) *print-lines*)
208 ((:pprint-dispatch *print-pprint-dispatch*)
209 *print-pprint-dispatch*))
211 "Returns the printed representation of OBJECT as a string."
212 (stringify-object object))
214 (defun prin1-to-string (object)
216 "Returns the printed representation of OBJECT as a string with
218 (stringify-object object t))
220 (defun princ-to-string (object)
222 "Returns the printed representation of OBJECT as a string with
224 (stringify-object object nil))
226 ;;; This produces the printed representation of an object as a string.
227 ;;; The few ...-TO-STRING functions above call this.
228 (defvar *string-output-streams* ())
229 (defun stringify-object (object &optional (*print-escape* *print-escape*))
230 (let ((stream (if *string-output-streams*
231 (pop *string-output-streams*)
232 (make-string-output-stream))))
233 (setup-printer-state)
234 (output-object object stream)
236 (get-output-stream-string stream)
237 (push stream *string-output-streams*))))
239 ;;;; support for the PRINT-UNREADABLE-OBJECT macro
241 ;;; guts of PRINT-UNREADABLE-OBJECT
242 (defun %print-unreadable-object (object stream type identity body)
243 (when *print-readably*
244 (error 'print-not-readable :object object))
245 (flet ((print-description ()
247 (write (type-of object) :stream stream :circle nil
248 :level nil :length nil)
249 (when (or body identity)
250 (write-char #\space stream)
251 (pprint-newline :fill stream)))
256 (write-char #\space stream)
257 (pprint-newline :fill stream))
258 (write-char #\{ stream)
259 (write (get-lisp-obj-address object) :stream stream
261 (write-char #\} stream))))
262 (cond ((print-pretty-on-stream-p stream)
263 ;; Since we're printing prettily on STREAM, format the
264 ;; object within a logical block. PPRINT-LOGICAL-BLOCK does
265 ;; not rebind the stream when it is already a pretty stream,
266 ;; so output from the body will go to the same stream.
267 (pprint-logical-block (stream nil :prefix "#<" :suffix ">")
268 (print-description)))
270 (write-string "#<" stream)
272 (write-char #\> stream))))
275 ;;;; circularity detection stuff
277 ;;; When *PRINT-CIRCLE* is T, this gets bound to a hash table that
278 ;;; (eventually) ends up with entries for every object printed. When
279 ;;; we are initially looking for circularities, we enter a T when we
280 ;;; find an object for the first time, and a 0 when we encounter an
281 ;;; object a second time around. When we are actually printing, the 0
282 ;;; entries get changed to the actual marker value when they are first
284 (defvar *circularity-hash-table* nil)
286 ;;; When NIL, we are just looking for circularities. After we have
287 ;;; found them all, this gets bound to 0. Then whenever we need a new
288 ;;; marker, it is incremented.
289 (defvar *circularity-counter* nil)
291 (defun check-for-circularity (object &optional assign)
293 "Check to see whether OBJECT is a circular reference, and return something
294 non-NIL if it is. If ASSIGN is T, then the number to use in the #n= and
295 #n# noise is assigned at this time. Note: CHECK-FOR-CIRCULARITY must
296 be called *EXACTLY* once with ASSIGN T, or the circularity detection noise
297 will get confused about when to use #n= and when to use #n#. If this
298 returns non-NIL when ASSIGN is T, then you must call HANDLE-CIRCULARITY
299 on it. If you are not using this inside a WITH-CIRCULARITY-DETECTION,
300 then you have to be prepared to handle a return value of :INITIATE which
301 means it needs to initiate the circularity detection noise. See the
302 source for info on how to do that."
303 (cond ((null *print-circle*)
304 ;; Don't bother, nobody cares.
306 ((null *circularity-hash-table*)
308 ((null *circularity-counter*)
309 (ecase (gethash object *circularity-hash-table*)
312 (setf (gethash object *circularity-hash-table*) t)
313 ;; We need to keep looking.
317 (setf (gethash object *circularity-hash-table*) 0)
318 ;; It's a circular reference.
321 ;; It's a circular reference.
324 (let ((value (gethash object *circularity-hash-table*)))
327 ;; If NIL, we found an object that wasn't there the first time
328 ;; around. If T, exactly one occurance of this object appears.
329 ;; Either way, just print the thing without any special
330 ;; processing. Note: you might argue that finding a new object
331 ;; means that something is broken, but this can happen. If
332 ;; someone uses the ~@<...~:> format directive, it conses a
333 ;; new list each time though format (i.e. the &REST list), so
334 ;; we will have different cdrs.
338 (let ((value (incf *circularity-counter*)))
339 ;; First occurance of this object. Set the counter.
340 (setf (gethash object *circularity-hash-table*) value)
344 ;; Second or later occurance.
347 (defun handle-circularity (marker stream)
349 "Handle the results of CHECK-FOR-CIRCULARITY. If this returns T then
350 you should go ahead and print the object. If it returns NIL, then
351 you should blow it off."
354 ;; Someone forgot to initiate circularity detection.
355 (let ((*print-circle* nil))
356 (error "trying to use CHECK-FOR-CIRCULARITY when ~
357 circularity checking isn't initiated")))
359 ;; It's a second (or later) reference to the object while we are
360 ;; just looking. So don't bother groveling it again.
363 (write-char #\# stream)
364 (let ((*print-base* 10) (*print-radix* nil))
365 (cond ((minusp marker)
366 (output-integer (- marker) stream)
367 (write-char #\# stream)
370 (output-integer marker stream)
371 (write-char #\= stream)
374 ;;;; OUTPUT-OBJECT -- the main entry point
376 (defvar *pretty-printer* nil
378 "The current pretty printer. Should be either a function that takes two
379 arguments (the object and the stream) or NIL to indicate that there is
380 no pretty printer installed.")
382 (defun output-object (object stream)
384 "Output OBJECT to STREAM observing all printer control variables."
385 (labels ((print-it (stream)
388 (funcall *pretty-printer* object stream)
389 (let ((*print-pretty* nil))
390 (output-ugly-object object stream)))
391 (output-ugly-object object stream)))
393 (let ((marker (check-for-circularity object t)))
396 (let ((*circularity-hash-table*
397 (make-hash-table :test 'eq)))
398 (check-it (make-broadcast-stream))
399 (let ((*circularity-counter* 0))
404 (when (handle-circularity marker stream)
405 (print-it stream)))))))
406 (cond ((or (not *print-circle*)
409 (and (symbolp object) (symbol-package object) t))
410 ;; If it a number, character, or interned symbol, we do not
411 ;; want to check for circularity/sharing.
413 ((or *circularity-hash-table*
415 (typep object 'instance)
416 (typep object '(array t *)))
417 ;; If we have already started circularity detection, this
418 ;; object might be a sharded reference. If we have not,
419 ;; then if it is a cons, a instance, or an array of element
420 ;; type t it might contain a circular reference to itself
421 ;; or multiple shared references.
424 (print-it stream)))))
426 (defun output-ugly-object (object stream)
428 "Output OBJECT to STREAM observing all printer control variables except
429 for *PRINT-PRETTY*. Note: if *PRINT-PRETTY* is non-NIL, then the pretty
430 printer will be used for any components of OBJECT, just not for OBJECT
433 ;; KLUDGE: The TYPECASE approach here is non-ANSI; the ANSI definition of
434 ;; PRINT-OBJECT says it provides printing and we're supposed to provide
435 ;; PRINT-OBJECT methods covering all classes. We deviate from this
436 ;; by using PRINT-OBJECT only when we print instance values. However,
437 ;; ANSI makes it hard to tell that we're deviating from this:
438 ;; (1) ANSI specifies that the user isn't supposed to call PRINT-OBJECT
440 ;; (2) ANSI (section 11.1.2.1.2) says it's undefined to define
441 ;; a method on an external symbol in the CL package which is
442 ;; applicable to arg lists containing only direct instances of
443 ;; standardized classes.
444 ;; Thus, in order for the user to detect our sleaziness, he has to do
445 ;; something relatively obscure like
446 ;; (1) actually use tools like FIND-METHOD to look for PRINT-OBJECT
448 ;; (2) define a PRINT-OBJECT method which is specialized on the stream
449 ;; value (e.g. a Gray stream object).
450 ;; As long as no one comes up with a non-obscure way of detecting this
451 ;; sleaziness, fixing this nonconformity will probably have a low
452 ;; priority. -- WHN 20000121
454 (output-integer object stream))
457 (output-symbol object stream)
458 (output-list object stream)))
460 (print-object object stream))
462 (unless (and (funcallable-instance-p object)
463 (printed-as-funcallable-standard-class object stream))
464 (output-function object stream)))
466 (output-symbol object stream))
470 (output-integer object stream))
472 (output-float object stream))
474 (output-ratio object stream))
476 (output-ratio object stream))
478 (output-complex object stream))))
480 (output-character object stream))
482 (output-vector object stream))
484 (output-array object stream))
486 (output-sap object stream))
488 (output-weak-pointer object stream))
490 (output-lra object stream))
492 (output-code-component object stream))
494 (output-fdefn object stream))
496 (output-random object stream))))
500 ;;; Values of *PRINT-CASE* and (READTABLE-CASE *READTABLE*) the last
501 ;;; time the printer was called.
502 (defvar *previous-case* nil)
503 (defvar *previous-readtable-case* nil)
505 ;;; This variable contains the current definition of one of three
506 ;;; symbol printers. SETUP-PRINTER-STATE sets this variable.
507 (defvar *internal-symbol-output-function* nil)
509 ;;; This function sets the internal global symbol
510 ;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION* to the right function depending
511 ;;; on the value of *PRINT-CASE*. See the manual for details. The
512 ;;; print buffer stream is also reset.
513 (defun setup-printer-state ()
514 (unless (and (eq *print-case* *previous-case*)
515 (eq (readtable-case *readtable*) *previous-readtable-case*))
516 (setq *previous-case* *print-case*)
517 (setq *previous-readtable-case* (readtable-case *readtable*))
518 (unless (member *print-case* '(:upcase :downcase :capitalize))
519 (setq *print-case* :upcase)
520 (error "invalid *PRINT-CASE* value: ~S" *previous-case*))
521 (unless (member *previous-readtable-case*
522 '(:upcase :downcase :invert :preserve))
523 (setf (readtable-case *readtable*) :upcase)
524 (error "invalid READTABLE-CASE value: ~S" *previous-readtable-case*))
526 (setq *internal-symbol-output-function*
527 (case *previous-readtable-case*
530 (:upcase #'output-preserve-symbol)
531 (:downcase #'output-lowercase-symbol)
532 (:capitalize #'output-capitalize-symbol)))
535 (:upcase #'output-uppercase-symbol)
536 (:downcase #'output-preserve-symbol)
537 (:capitalize #'output-capitalize-symbol)))
538 (:preserve #'output-preserve-symbol)
539 (:invert #'output-invert-symbol)))))
541 ;;; Output PNAME (a symbol-name or package-name) surrounded with |'s,
542 ;;; and with any embedded |'s or \'s escaped.
543 (defun output-quoted-symbol-name (pname stream)
544 (write-char #\| stream)
545 (dotimes (index (length pname))
546 (let ((char (schar pname index)))
547 (when (or (char= char #\\) (char= char #\|))
548 (write-char #\\ stream))
549 (write-char char stream)))
550 (write-char #\| stream))
552 (defun output-symbol (object stream)
553 (if (or *print-escape* *print-readably*)
554 (let ((package (symbol-package object))
555 (name (symbol-name object)))
557 ;; The ANSI spec "22.1.3.3.1 Package Prefixes for Symbols"
558 ;; requires that keywords be printed with preceding colons
559 ;; always, regardless of the value of *PACKAGE*.
560 ((eq package *keyword-package*)
561 (write-char #\: stream))
562 ;; Otherwise, if the symbol's home package is the current
563 ;; one, then a prefix is never necessary.
564 ((eq package (sane-package)))
565 ;; Uninterned symbols print with a leading #:.
567 (when (or *print-gensym* *print-readably*)
568 (write-string "#:" stream)))
570 (multiple-value-bind (symbol accessible)
571 (find-symbol name (sane-package))
572 ;; If we can find the symbol by looking it up, it need not
573 ;; be qualified. This can happen if the symbol has been
574 ;; inherited from a package other than its home package.
575 (unless (and accessible (eq symbol object))
576 (output-symbol-name (package-name package) stream)
577 (multiple-value-bind (symbol externalp)
578 (find-external-symbol name package)
579 (declare (ignore symbol))
581 (write-char #\: stream)
582 (write-string "::" stream)))))))
583 (output-symbol-name name stream))
584 (output-symbol-name (symbol-name object) stream nil)))
586 ;;; Output the string NAME as if it were a symbol name. In other
587 ;;; words, diddle its case according to *PRINT-CASE* and
589 (defun output-symbol-name (name stream &optional (maybe-quote t))
590 (declare (type simple-base-string name))
591 (setup-printer-state)
592 (if (and maybe-quote (symbol-quotep name))
593 (output-quoted-symbol-name name stream)
594 (funcall *internal-symbol-output-function* name stream)))
596 ;;;; escaping symbols
598 ;;; When we print symbols we have to figure out if they need to be
599 ;;; printed with escape characters. This isn't a whole lot easier than
600 ;;; reading symbols in the first place.
602 ;;; For each character, the value of the corresponding element is a
603 ;;; fixnum with bits set corresponding to attributes that the
604 ;;; character has. At characters have at least one bit set, so we can
605 ;;; search for any character with a positive test.
606 (defvar *character-attributes*
607 (make-array char-code-limit
608 :element-type '(unsigned-byte 16)
610 (declaim (type (simple-array (unsigned-byte 16) (#.char-code-limit))
611 *character-attributes*))
613 ;;; Constants which are a bit-mask for each interesting character attribute.
614 (defconstant other-attribute (ash 1 0)) ; Anything else legal.
615 (defconstant number-attribute (ash 1 1)) ; A numeric digit.
616 (defconstant uppercase-attribute (ash 1 2)) ; An uppercase letter.
617 (defconstant lowercase-attribute (ash 1 3)) ; A lowercase letter.
618 (defconstant sign-attribute (ash 1 4)) ; +-
619 (defconstant extension-attribute (ash 1 5)) ; ^_
620 (defconstant dot-attribute (ash 1 6)) ; .
621 (defconstant slash-attribute (ash 1 7)) ; /
622 (defconstant funny-attribute (ash 1 8)) ; Anything illegal.
624 (eval-when (:compile-toplevel :load-toplevel :execute)
626 ;;; LETTER-ATTRIBUTE is a local of SYMBOL-QUOTEP. It matches letters
627 ;;; that don't need to be escaped (according to READTABLE-CASE.)
628 (defparameter *attribute-names*
629 `((number . number-attribute) (lowercase . lowercase-attribute)
630 (uppercase . uppercase-attribute) (letter . letter-attribute)
631 (sign . sign-attribute) (extension . extension-attribute)
632 (dot . dot-attribute) (slash . slash-attribute)
633 (other . other-attribute) (funny . funny-attribute)))
637 (flet ((set-bit (char bit)
638 (let ((code (char-code char)))
639 (setf (aref *character-attributes* code)
640 (logior bit (aref *character-attributes* code))))))
642 (dolist (char '(#\! #\@ #\$ #\% #\& #\* #\= #\~ #\[ #\] #\{ #\}
644 (set-bit char other-attribute))
647 (set-bit (digit-char i) number-attribute))
649 (do ((code (char-code #\A) (1+ code))
650 (end (char-code #\Z)))
652 (declare (fixnum code end))
653 (set-bit (code-char code) uppercase-attribute)
654 (set-bit (char-downcase (code-char code)) lowercase-attribute))
656 (set-bit #\- sign-attribute)
657 (set-bit #\+ sign-attribute)
658 (set-bit #\^ extension-attribute)
659 (set-bit #\_ extension-attribute)
660 (set-bit #\. dot-attribute)
661 (set-bit #\/ slash-attribute)
663 ;; Mark anything not explicitly allowed as funny.
664 (dotimes (i char-code-limit)
665 (when (zerop (aref *character-attributes* i))
666 (setf (aref *character-attributes* i) funny-attribute))))
668 ;;; For each character, the value of the corresponding element is the
669 ;;; lowest base in which that character is a digit.
670 (defvar *digit-bases*
671 (make-array char-code-limit
672 :element-type '(unsigned-byte 8)
673 :initial-element 36))
674 (declaim (type (simple-array (unsigned-byte 8) (#.char-code-limit))
678 (let ((char (digit-char i 36)))
679 (setf (aref *digit-bases* (char-code char)) i)))
681 ;;; A FSM-like thingie that determines whether a symbol is a potential
682 ;;; number or has evil characters in it.
683 (defun symbol-quotep (name)
684 (declare (simple-string name))
685 (macrolet ((advance (tag &optional (at-end t))
688 ,(if at-end '(go TEST-SIGN) '(return nil)))
689 (setq current (schar name index)
690 code (char-code current)
691 bits (aref attributes code))
694 (test (&rest attributes)
706 `(< (the fixnum (aref bases code)) base)))
708 (prog ((len (length name))
709 (attributes *character-attributes*)
710 (bases *digit-bases*)
713 (case (readtable-case *readtable*)
714 (:upcase uppercase-attribute)
715 (:downcase lowercase-attribute)
716 (t (logior lowercase-attribute uppercase-attribute))))
721 (declare (fixnum len base index bits code))
724 TEST-SIGN ; At end, see whether it is a sign...
725 (return (not (test sign)))
727 OTHER ; not potential number, see whether funny chars...
728 (let ((mask (logxor (logior lowercase-attribute uppercase-attribute
731 (do ((i (1- index) (1+ i)))
732 ((= i len) (return-from symbol-quotep nil))
733 (unless (zerop (logand (aref attributes (char-code (schar name i)))
735 (return-from symbol-quotep t))))
740 (advance LAST-DIGIT-ALPHA)
742 (when (test letter number other slash) (advance OTHER nil))
743 (when (char= current #\.) (advance DOT-FOUND))
744 (when (test sign extension) (advance START-STUFF nil))
747 DOT-FOUND ; leading dots...
748 (when (test letter) (advance START-DOT-MARKER nil))
749 (when (digitp) (advance DOT-DIGIT))
750 (when (test number other) (advance OTHER nil))
751 (when (test extension slash sign) (advance START-DOT-STUFF nil))
752 (when (char= current #\.) (advance DOT-FOUND))
755 START-STUFF ; leading stuff before any dot or digit
758 (advance LAST-DIGIT-ALPHA)
760 (when (test number other) (advance OTHER nil))
761 (when (test letter) (advance START-MARKER nil))
762 (when (char= current #\.) (advance START-DOT-STUFF nil))
763 (when (test sign extension slash) (advance START-STUFF nil))
766 START-MARKER ; number marker in leading stuff...
767 (when (test letter) (advance OTHER nil))
770 START-DOT-STUFF ; leading stuff containing dot w/o digit...
771 (when (test letter) (advance START-DOT-STUFF nil))
772 (when (digitp) (advance DOT-DIGIT))
773 (when (test sign extension dot slash) (advance START-DOT-STUFF nil))
774 (when (test number other) (advance OTHER nil))
777 START-DOT-MARKER ; number marker in leading stuff w/ dot..
778 ;; leading stuff containing dot w/o digit followed by letter...
779 (when (test letter) (advance OTHER nil))
782 DOT-DIGIT ; in a thing with dots...
783 (when (test letter) (advance DOT-MARKER))
784 (when (digitp) (advance DOT-DIGIT))
785 (when (test number other) (advance OTHER nil))
786 (when (test sign extension dot slash) (advance DOT-DIGIT))
789 DOT-MARKER ; number marker in number with dot...
790 (when (test letter) (advance OTHER nil))
793 LAST-DIGIT-ALPHA ; previous char is a letter digit...
794 (when (or (digitp) (test sign slash))
795 (advance ALPHA-DIGIT))
796 (when (test letter number other dot) (advance OTHER nil))
799 ALPHA-DIGIT ; seen a digit which is a letter...
800 (when (or (digitp) (test sign slash))
802 (advance LAST-DIGIT-ALPHA)
803 (advance ALPHA-DIGIT)))
804 (when (test letter) (advance ALPHA-MARKER))
805 (when (test number other dot) (advance OTHER nil))
808 ALPHA-MARKER ; number marker in number with alpha digit...
809 (when (test letter) (advance OTHER nil))
812 DIGIT ; seen only ordinary (non-alphabetic) numeric digits...
815 (advance ALPHA-DIGIT)
817 (when (test number other) (advance OTHER nil))
818 (when (test letter) (advance MARKER))
819 (when (test extension slash sign) (advance DIGIT))
820 (when (char= current #\.) (advance DOT-DIGIT))
823 MARKER ; number marker in a numeric number...
824 (when (test letter) (advance OTHER nil))
827 ;;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION*
829 ;;;; Case hackery. These functions are stored in
830 ;;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION* according to the values of
831 ;;;; *PRINT-CASE* and READTABLE-CASE.
834 ;;; READTABLE-CASE *PRINT-CASE*
836 ;;; :DOWNCASE :DOWNCASE
838 (defun output-preserve-symbol (pname stream)
839 (declare (simple-string pname))
840 (write-string pname stream))
843 ;;; READTABLE-CASE *PRINT-CASE*
844 ;;; :UPCASE :DOWNCASE
845 (defun output-lowercase-symbol (pname stream)
846 (declare (simple-string pname))
847 (dotimes (index (length pname))
848 (let ((char (schar pname index)))
849 (write-char (char-downcase char) stream))))
852 ;;; READTABLE-CASE *PRINT-CASE*
853 ;;; :DOWNCASE :UPCASE
854 (defun output-uppercase-symbol (pname stream)
855 (declare (simple-string pname))
856 (dotimes (index (length pname))
857 (let ((char (schar pname index)))
858 (write-char (char-upcase char) stream))))
861 ;;; READTABLE-CASE *PRINT-CASE*
862 ;;; :UPCASE :CAPITALIZE
863 ;;; :DOWNCASE :CAPITALIZE
864 (defun output-capitalize-symbol (pname stream)
865 (declare (simple-string pname))
866 (let ((prev-not-alpha t)
867 (up (eq (readtable-case *readtable*) :upcase)))
868 (dotimes (i (length pname))
869 (let ((char (char pname i)))
871 (if (or prev-not-alpha (lower-case-p char))
873 (char-downcase char))
878 (setq prev-not-alpha (not (alpha-char-p char)))))))
881 ;;; READTABLE-CASE *PRINT-CASE*
883 (defun output-invert-symbol (pname stream)
884 (declare (simple-string pname))
887 (dotimes (i (length pname))
888 (let ((ch (schar pname i)))
889 (when (both-case-p ch)
890 (if (upper-case-p ch)
892 (setq all-upper nil)))))
893 (cond (all-upper (output-lowercase-symbol pname stream))
894 (all-lower (output-uppercase-symbol pname stream))
896 (write-string pname stream)))))
900 (let ((*readtable* (copy-readtable nil)))
901 (format t "READTABLE-CASE Input Symbol-name~@
902 ----------------------------------~%")
903 (dolist (readtable-case '(:upcase :downcase :preserve :invert))
904 (setf (readtable-case *readtable*) readtable-case)
905 (dolist (input '("ZEBRA" "Zebra" "zebra"))
906 (format t "~&:~A~16T~A~24T~A"
907 (string-upcase readtable-case)
909 (symbol-name (read-from-string input)))))))
912 (let ((*readtable* (copy-readtable nil)))
913 (format t "READTABLE-CASE *PRINT-CASE* Symbol-name Output Princ~@
914 --------------------------------------------------------~%")
915 (dolist (readtable-case '(:upcase :downcase :preserve :invert))
916 (setf (readtable-case *readtable*) readtable-case)
917 (dolist (*print-case* '(:upcase :downcase :capitalize))
918 (dolist (symbol '(|ZEBRA| |Zebra| |zebra|))
919 (format t "~&:~A~15T:~A~29T~A~42T~A~50T~A"
920 (string-upcase readtable-case)
921 (string-upcase *print-case*)
923 (prin1-to-string symbol)
924 (princ-to-string symbol)))))))
927 ;;;; recursive objects
929 (defun output-list (list stream)
930 (descend-into (stream)
931 (write-char #\( stream)
935 (punt-print-if-too-long length stream)
936 (output-object (pop list) stream)
939 (when (or (atom list) (check-for-circularity list))
940 (write-string " . " stream)
941 (output-object list stream)
943 (write-char #\space stream)
945 (write-char #\) stream)))
947 (defun output-vector (vector stream)
948 (declare (vector vector))
949 (cond ((stringp vector)
950 (cond ((or *print-escape* *print-readably*)
951 (write-char #\" stream)
952 (quote-string vector stream)
953 (write-char #\" stream))
955 (write-string vector stream))))
956 ((not (or *print-array* *print-readably*))
957 (output-terse-array vector stream))
958 ((bit-vector-p vector)
959 (write-string "#*" stream)
960 (dotimes (i (length vector))
961 (output-object (aref vector i) stream)))
963 (when (and *print-readably*
964 (not (eq (array-element-type vector) t)))
965 (error 'print-not-readable :object vector))
966 (descend-into (stream)
967 (write-string "#(" stream)
968 (dotimes (i (length vector))
970 (write-char #\space stream))
971 (punt-print-if-too-long i stream)
972 (output-object (aref vector i) stream))
973 (write-string ")" stream)))))
975 ;;; This function outputs a string quoting characters sufficiently
976 ;;; that so someone can read it in again. Basically, put a slash in
977 ;;; front of an character satisfying NEEDS-SLASH-P.
978 (defun quote-string (string stream)
979 (macrolet ((needs-slash-p (char)
980 ;; KLUDGE: We probably should look at the readtable, but just do
981 ;; this for now. [noted by anonymous long ago] -- WHN 19991130
982 `(or (char= ,char #\\)
984 (with-array-data ((data string) (start) (end (length string)))
985 (do ((index start (1+ index)))
987 (let ((char (schar data index)))
988 (when (needs-slash-p char) (write-char #\\ stream))
989 (write-char char stream))))))
991 (defun output-array (array stream)
993 "Outputs the printed representation of any array in either the #< or #A
995 (if (or *print-array* *print-readably*)
996 (output-array-guts array stream)
997 (output-terse-array array stream)))
999 ;;; to output the abbreviated #< form of an array
1000 (defun output-terse-array (array stream)
1001 (let ((*print-level* nil)
1002 (*print-length* nil))
1003 (print-unreadable-object (array stream :type t :identity t))))
1005 ;;; to output the readable #A form of an array
1006 (defun output-array-guts (array stream)
1007 (when (and *print-readably*
1008 (not (eq (array-element-type array) t)))
1009 (error 'print-not-readable :object array))
1010 (write-char #\# stream)
1011 (let ((*print-base* 10))
1012 (output-integer (array-rank array) stream))
1013 (write-char #\A stream)
1014 (with-array-data ((data array) (start) (end))
1015 (declare (ignore end))
1016 (sub-output-array-guts data (array-dimensions array) stream start)))
1018 (defun sub-output-array-guts (array dimensions stream index)
1019 (declare (type (simple-array * (*)) array) (fixnum index))
1020 (cond ((null dimensions)
1021 (output-object (aref array index) stream))
1023 (descend-into (stream)
1024 (write-char #\( stream)
1025 (let* ((dimension (car dimensions))
1026 (dimensions (cdr dimensions))
1027 (count (reduce #'* dimensions)))
1028 (dotimes (i dimension)
1030 (write-char #\space stream))
1031 (punt-print-if-too-long i stream)
1032 (sub-output-array-guts array dimensions stream index)
1033 (incf index count)))
1034 (write-char #\) stream)))))
1036 ;;; a trivial non-generic-function placeholder for PRINT-OBJECT, for
1037 ;;; use until CLOS is set up (at which time it will be replaced with
1038 ;;; the real generic function implementation)
1039 (defun print-object (instance stream)
1040 (default-structure-print instance stream *current-level*))
1042 ;;;; integer, ratio, and complex printing (i.e. everything but floats)
1044 (defun output-integer (integer stream)
1045 ;; FIXME: This UNLESS form should be pulled out into something like
1046 ;; (SANE-PRINT-BASE), along the lines of (SANE-PACKAGE) for the
1047 ;; *PACKAGE* variable.
1048 (unless (and (fixnump *print-base*)
1049 (< 1 *print-base* 37))
1050 (let ((obase *print-base*))
1051 (setq *print-base* 10.)
1052 (error "~A is not a reasonable value for *PRINT-BASE*." obase)))
1053 (when (and (not (= *print-base* 10.))
1055 ;; First print leading base information, if any.
1056 (write-char #\# stream)
1057 (write-char (case *print-base*
1061 (T (let ((fixbase *print-base*)
1064 (sub-output-integer fixbase stream))
1067 ;; Then output a minus sign if the number is negative, then output
1068 ;; the absolute value of the number.
1069 (cond ((bignump integer) (print-bignum integer stream))
1071 (write-char #\- stream)
1072 (sub-output-integer (- integer) stream))
1074 (sub-output-integer integer stream)))
1075 ;; Print any trailing base information, if any.
1076 (if (and (= *print-base* 10.) *print-radix*)
1077 (write-char #\. stream)))
1079 (defun sub-output-integer (integer stream)
1082 ;; Recurse until you have all the digits pushed on the stack.
1083 (if (not (zerop (multiple-value-setq (quotient remainder)
1084 (truncate integer *print-base*))))
1085 (sub-output-integer quotient stream))
1086 ;; Then as each recursive call unwinds, turn the digit (in remainder)
1087 ;; into a character and output the character.
1088 (write-char (code-char (if (and (> remainder 9.)
1089 (> *print-base* 10.))
1090 (+ (char-code #\A) (- remainder 10.))
1091 (+ (char-code #\0) remainder)))
1094 ;;;; bignum printing
1096 ;;; *BASE-POWER* holds the number that we keep dividing into the
1097 ;;; bignum for each *print-base*. We want this number as close to
1098 ;;; *most-positive-fixnum* as possible, i.e. (floor (log
1099 ;;; most-positive-fixnum *print-base*)).
1100 (defparameter *base-power* (make-array 37 :initial-element nil))
1102 ;;; *FIXNUM-POWER--1* holds the number of digits for each *PRINT-BASE*
1103 ;;; that fit in the corresponding *base-power*.
1104 (defparameter *fixnum-power--1* (make-array 37 :initial-element nil))
1106 ;;; Print the bignum to the stream. We first generate the correct
1107 ;;; value for *base-power* and *fixnum-power--1* if we have not
1108 ;;; already. Then we call bignum-print-aux to do the printing.
1109 (defun print-bignum (big stream)
1110 (unless (aref *base-power* *print-base*)
1111 (do ((power-1 -1 (1+ power-1))
1112 (new-divisor *print-base* (* new-divisor *print-base*))
1113 (divisor 1 new-divisor))
1114 ((not (fixnump new-divisor))
1115 (setf (aref *base-power* *print-base*) divisor)
1116 (setf (aref *fixnum-power--1* *print-base*) power-1))))
1117 (bignum-print-aux (cond ((minusp big)
1118 (write-char #\- stream)
1121 (aref *base-power* *print-base*)
1122 (aref *fixnum-power--1* *print-base*)
1126 (defun bignum-print-aux (big divisor power-1 stream)
1127 (multiple-value-bind (newbig fix) (truncate big divisor)
1128 (if (fixnump newbig)
1129 (sub-output-integer newbig stream)
1130 (bignum-print-aux newbig divisor power-1 stream))
1131 (do ((zeros power-1 (1- zeros))
1132 (base-power *print-base* (* base-power *print-base*)))
1134 (dotimes (i zeros) (write-char #\0 stream))
1135 (sub-output-integer fix stream)))))
1137 (defun output-ratio (ratio stream)
1139 (write-char #\# stream)
1141 (2 (write-char #\b stream))
1142 (8 (write-char #\o stream))
1143 (16 (write-char #\x stream))
1144 (t (write *print-base* :stream stream :radix nil :base 10)))
1145 (write-char #\r stream))
1146 (let ((*print-radix* nil))
1147 (output-integer (numerator ratio) stream)
1148 (write-char #\/ stream)
1149 (output-integer (denominator ratio) stream)))
1151 (defun output-complex (complex stream)
1152 (write-string "#C(" stream)
1153 (output-object (realpart complex) stream)
1154 (write-char #\space stream)
1155 (output-object (imagpart complex) stream)
1156 (write-char #\) stream))
1160 ;;; FLONUM-TO-STRING (and its subsidiary function FLOAT-STRING) does
1161 ;;; most of the work for all printing of floating point numbers in the
1162 ;;; printer and in FORMAT. It converts a floating point number to a
1163 ;;; string in a free or fixed format with no exponent. The
1164 ;;; interpretation of the arguments is as follows:
1166 ;;; X - The floating point number to convert, which must not be
1168 ;;; WIDTH - The preferred field width, used to determine the number
1169 ;;; of fraction digits to produce if the FDIGITS parameter
1170 ;;; is unspecified or NIL. If the non-fraction digits and the
1171 ;;; decimal point alone exceed this width, no fraction digits
1172 ;;; will be produced unless a non-NIL value of FDIGITS has been
1173 ;;; specified. Field overflow is not considerd an error at this
1175 ;;; FDIGITS - The number of fractional digits to produce. Insignificant
1176 ;;; trailing zeroes may be introduced as needed. May be
1177 ;;; unspecified or NIL, in which case as many digits as possible
1178 ;;; are generated, subject to the constraint that there are no
1179 ;;; trailing zeroes.
1180 ;;; SCALE - If this parameter is specified or non-NIL, then the number
1181 ;;; printed is (* x (expt 10 scale)). This scaling is exact,
1182 ;;; and cannot lose precision.
1183 ;;; FMIN - This parameter, if specified or non-NIL, is the minimum
1184 ;;; number of fraction digits which will be produced, regardless
1185 ;;; of the value of WIDTH or FDIGITS. This feature is used by
1186 ;;; the ~E format directive to prevent complete loss of
1187 ;;; significance in the printed value due to a bogus choice of
1190 ;;; Most of the optional arguments are for the benefit for FORMAT and are not
1191 ;;; used by the printer.
1194 ;;; (VALUES DIGIT-STRING DIGIT-LENGTH LEADING-POINT TRAILING-POINT DECPNT)
1195 ;;; where the results have the following interpretation:
1197 ;;; DIGIT-STRING - The decimal representation of X, with decimal point.
1198 ;;; DIGIT-LENGTH - The length of the string DIGIT-STRING.
1199 ;;; LEADING-POINT - True if the first character of DIGIT-STRING is the
1201 ;;; TRAILING-POINT - True if the last character of DIGIT-STRING is the
1203 ;;; POINT-POS - The position of the digit preceding the decimal
1204 ;;; point. Zero indicates point before first digit.
1206 ;;; NOTE: FLONUM-TO-STRING goes to a lot of trouble to guarantee
1207 ;;; accuracy. Specifically, the decimal number printed is the closest
1208 ;;; possible approximation to the true value of the binary number to
1209 ;;; be printed from among all decimal representations with the same
1210 ;;; number of digits. In free-format output, i.e. with the number of
1211 ;;; digits unconstrained, it is guaranteed that all the information is
1212 ;;; preserved, so that a properly- rounding reader can reconstruct the
1213 ;;; original binary number, bit-for-bit, from its printed decimal
1214 ;;; representation. Furthermore, only as many digits as necessary to
1215 ;;; satisfy this condition will be printed.
1217 ;;; FLOAT-STRING actually generates the digits for positive numbers.
1218 ;;; The algorithm is essentially that of algorithm Dragon4 in "How to
1219 ;;; Print Floating-Point Numbers Accurately" by Steele and White. The
1220 ;;; current (draft) version of this paper may be found in
1221 ;;; [CMUC]<steele>tradix.press. DO NOT EVEN THINK OF ATTEMPTING TO
1222 ;;; UNDERSTAND THIS CODE WITHOUT READING THE PAPER!
1224 (defvar *digits* "0123456789")
1226 (defun flonum-to-string (x &optional width fdigits scale fmin)
1228 ;; Zero is a special case which FLOAT-STRING cannot handle.
1230 (let ((s (make-string (1+ fdigits) :initial-element #\0)))
1231 (setf (schar s 0) #\.)
1232 (values s (length s) t (zerop fdigits) 0))
1233 (values "." 1 t t 0)))
1235 (multiple-value-bind (sig exp) (integer-decode-float x)
1236 (let* ((precision (float-precision x))
1237 (digits (float-digits x))
1238 (fudge (- digits precision))
1239 (width (if width (max width 1) nil)))
1240 (float-string (ash sig (- fudge)) (+ exp fudge) precision width
1241 fdigits scale fmin))))))
1243 (defun float-string (fraction exponent precision width fdigits scale fmin)
1244 (let ((r fraction) (s 1) (m- 1) (m+ 1) (k 0)
1245 (digits 0) (decpnt 0) (cutoff nil) (roundup nil) u low high
1246 (digit-string (make-array 50
1247 :element-type 'base-char
1250 ;; Represent fraction as r/s, error bounds as m+/s and m-/s.
1251 ;; Rational arithmetic avoids loss of precision in subsequent
1253 (cond ((> exponent 0)
1254 (setq r (ash fraction exponent))
1255 (setq m- (ash 1 exponent))
1258 (setq s (ash 1 (- exponent)))))
1259 ;; Adjust the error bounds m+ and m- for unequal gaps.
1260 (when (= fraction (ash 1 precision))
1261 (setq m+ (ash m+ 1))
1264 ;; Scale value by requested amount, and update error bounds.
1267 (let ((scale-factor (expt 10 (- scale))))
1268 (setq s (* s scale-factor)))
1269 (let ((scale-factor (expt 10 scale)))
1270 (setq r (* r scale-factor))
1271 (setq m+ (* m+ scale-factor))
1272 (setq m- (* m- scale-factor)))))
1273 ;; Scale r and s and compute initial k, the base 10 logarithm of r.
1275 ((>= r (ceiling s 10)))
1279 (setq m+ (* m+ 10)))
1282 ((< (+ (ash r 1) m+) (ash s 1)))
1285 ;; Determine number of fraction digits to generate.
1287 ;; Use specified number of fraction digits.
1288 (setq cutoff (- fdigits))
1289 ;;don't allow less than fmin fraction digits
1290 (if (and fmin (> cutoff (- fmin))) (setq cutoff (- fmin))))
1292 ;; Use as many fraction digits as width will permit but
1293 ;; force at least fmin digits even if width will be
1296 (setq cutoff (- 1 width))
1297 (setq cutoff (1+ (- k width))))
1298 (if (and fmin (> cutoff (- fmin))) (setq cutoff (- fmin)))))
1299 ;; If we decided to cut off digit generation before precision
1300 ;; has been exhausted, rounding the last digit may cause a carry
1301 ;; propagation. We can prevent this, preserving left-to-right
1302 ;; digit generation, with a few magical adjustments to m- and
1303 ;; m+. Of course, correct rounding is also preserved.
1304 (when (or fdigits width)
1305 (let ((a (- cutoff k))
1308 (dotimes (i a) (setq y (* y 10)))
1309 (dotimes (i (- a)) (setq y (ceiling y 10))))
1310 (setq m- (max y m-))
1311 (setq m+ (max y m+))
1312 (when (= m+ y) (setq roundup t))))
1313 (when (< (+ (ash r 1) m+) (ash s 1)) (return)))
1314 ;; Zero-fill before fraction if no integer part.
1316 (setq decpnt digits)
1317 (vector-push-extend #\. digit-string)
1319 (incf digits) (vector-push-extend #\0 digit-string)))
1320 ;; Generate the significant digits.
1324 (vector-push-extend #\. digit-string)
1325 (setq decpnt digits))
1326 (multiple-value-setq (u r) (truncate (* r 10) s))
1329 (setq low (< (ash r 1) m-))
1331 (setq high (>= (ash r 1) (- (ash s 1) m+)))
1332 (setq high (> (ash r 1) (- (ash s 1) m+))))
1333 ;; Stop when either precision is exhausted or we have printed as
1334 ;; many fraction digits as permitted.
1335 (when (or low high (and cutoff (<= k cutoff))) (return))
1336 (vector-push-extend (char *digits* u) digit-string)
1338 ;; If cutoff occurred before first digit, then no digits are
1339 ;; generated at all.
1340 (when (or (not cutoff) (>= k cutoff))
1341 ;; Last digit may need rounding
1342 (vector-push-extend (char *digits*
1343 (cond ((and low (not high)) u)
1344 ((and high (not low)) (1+ u))
1345 (t (if (<= (ash r 1) s) u (1+ u)))))
1348 ;; Zero-fill after integer part if no fraction.
1350 (dotimes (i k) (incf digits) (vector-push-extend #\0 digit-string))
1351 (vector-push-extend #\. digit-string)
1352 (setq decpnt digits))
1353 ;; Add trailing zeroes to pad fraction if fdigits specified.
1355 (dotimes (i (- fdigits (- digits decpnt)))
1357 (vector-push-extend #\0 digit-string)))
1359 (values digit-string (1+ digits) (= decpnt 0) (= decpnt digits) decpnt)))
1361 ;;; Given a non-negative floating point number, SCALE-EXPONENT returns
1362 ;;; a new floating point number Z in the range (0.1, 1.0] and an
1363 ;;; exponent E such that Z * 10^E is (approximately) equal to the
1364 ;;; original number. There may be some loss of precision due the
1365 ;;; floating point representation. The scaling is always done with
1366 ;;; long float arithmetic, which helps printing of lesser precisions
1367 ;;; as well as avoiding generic arithmetic.
1369 ;;; When computing our initial scale factor using EXPT, we pull out
1370 ;;; part of the computation to avoid over/under flow. When
1371 ;;; denormalized, we must pull out a large factor, since there is more
1372 ;;; negative exponent range than positive range.
1373 (defun scale-exponent (original-x)
1374 (let* ((x (coerce original-x 'long-float)))
1375 (multiple-value-bind (sig exponent) (decode-float x)
1376 (declare (ignore sig))
1378 (values (float 0.0l0 original-x) 1)
1379 (let* ((ex (round (* exponent (log 2l0 10))))
1381 (if (float-denormalized-p x)
1383 (* x 1.0l16 (expt 10.0l0 (- (- ex) 16)))
1385 (* x 1.0l18 (expt 10.0l0 (- (- ex) 18)))
1386 (* x 10.0l0 (expt 10.0l0 (- (- ex) 1))))
1387 (/ x 10.0l0 (expt 10.0l0 (1- ex))))))
1388 (do ((d 10.0l0 (* d 10.0l0))
1392 (do ((m 10.0l0 (* m 10.0l0))
1396 (values (float z original-x) ex))))))))))
1398 ;;;; entry point for the float printer
1400 ;;; the float printer as called by PRINT, PRIN1, PRINC, etc. The
1401 ;;; argument is printed free-format, in either exponential or
1402 ;;; non-exponential notation, depending on its magnitude.
1404 ;;; NOTE: When a number is to be printed in exponential format, it is
1405 ;;; scaled in floating point. Since precision may be lost in this
1406 ;;; process, the guaranteed accuracy properties of FLONUM-TO-STRING
1407 ;;; are lost. The difficulty is that FLONUM-TO-STRING performs
1408 ;;; extensive computations with integers of similar magnitude to that
1409 ;;; of the number being printed. For large exponents, the bignums
1410 ;;; really get out of hand. If bignum arithmetic becomes reasonably
1411 ;;; fast and the exponent range is not too large, then it might become
1412 ;;; attractive to handle exponential notation with the same accuracy
1413 ;;; as non-exponential notation, using the method described in the
1414 ;;; Steele and White paper.
1416 ;;; Print the appropriate exponent marker for X and the specified exponent.
1417 (defun print-float-exponent (x exp stream)
1418 (declare (type float x) (type integer exp) (type stream stream))
1419 (let ((*print-radix* nil)
1420 (plusp (plusp exp)))
1421 (if (typep x *read-default-float-format*)
1423 (format stream "e~:[~;+~]~D" plusp exp))
1424 (format stream "~C~:[~;+~]~D"
1432 (defun output-float-infinity (x stream)
1433 (declare (float x) (stream stream))
1435 (write-string "#." stream))
1437 (error 'print-not-readable :object x))
1439 (write-string "#<" stream)))
1440 (write-string "SB-EXT:" stream)
1441 (write-string (symbol-name (float-format-name x)) stream)
1442 (write-string (if (plusp x) "-POSITIVE-" "-NEGATIVE-")
1444 (write-string "INFINITY" stream)
1446 (write-string ">" stream)))
1448 (defun output-float-nan (x stream)
1449 (print-unreadable-object (x stream)
1450 (princ (float-format-name x) stream)
1451 (write-string (if (float-trapping-nan-p x) " trapping" " quiet") stream)
1452 (write-string " NaN" stream)))
1454 ;;; the function called by OUTPUT-OBJECT to handle floats
1455 (defun output-float (x stream)
1457 ((float-infinity-p x)
1458 (output-float-infinity x stream))
1460 (output-float-nan x stream))
1462 (let ((x (cond ((minusp (float-sign x))
1463 (write-char #\- stream)
1469 (write-string "0.0" stream)
1470 (print-float-exponent x 0 stream))
1472 (output-float-aux x stream (float 1/1000 x) (float 10000000 x))))))))
1473 (defun output-float-aux (x stream e-min e-max)
1474 (if (and (>= x e-min) (< x e-max))
1476 (multiple-value-bind (str len lpoint tpoint) (flonum-to-string x)
1477 (declare (ignore len))
1478 (when lpoint (write-char #\0 stream))
1479 (write-string str stream)
1480 (when tpoint (write-char #\0 stream))
1481 (print-float-exponent x 0 stream))
1482 ;; exponential format
1483 (multiple-value-bind (f ex) (scale-exponent x)
1484 (multiple-value-bind (str len lpoint tpoint)
1485 (flonum-to-string f nil nil 1)
1486 (declare (ignore len))
1487 (when lpoint (write-char #\0 stream))
1488 (write-string str stream)
1489 (when tpoint (write-char #\0 stream))
1490 ;; Subtract out scale factor of 1 passed to FLONUM-TO-STRING.
1491 (print-float-exponent x (1- ex) stream)))))
1493 ;;;; other leaf objects
1495 ;;; If *PRINT-ESCAPE* is false, just do a WRITE-CHAR, otherwise output
1496 ;;; the character name or the character in the #\char format.
1497 (defun output-character (char stream)
1498 (if (or *print-escape* *print-readably*)
1499 (let ((name (char-name char)))
1500 (write-string "#\\" stream)
1502 (quote-string name stream)
1503 (write-char char stream)))
1504 (write-char char stream)))
1506 (defun output-sap (sap stream)
1507 (declare (type system-area-pointer sap))
1509 (format stream "#.(~S #X~8,'0X)" 'int-sap (sap-int sap)))
1511 (print-unreadable-object (sap stream)
1512 (format stream "system area pointer: #X~8,'0X" (sap-int sap))))))
1514 (defun output-weak-pointer (weak-pointer stream)
1515 (declare (type weak-pointer weak-pointer))
1516 (print-unreadable-object (weak-pointer stream)
1517 (multiple-value-bind (value validp) (weak-pointer-value weak-pointer)
1519 (write-string "weak pointer: " stream)
1520 (write value :stream stream))
1522 (write-string "broken weak pointer" stream))))))
1524 (defun output-code-component (component stream)
1525 (print-unreadable-object (component stream :identity t)
1526 (let ((dinfo (%code-debug-info component)))
1527 (cond ((eq dinfo :bogus-lra)
1528 (write-string "bogus code object" stream))
1530 (write-string "code object" stream)
1532 (write-char #\space stream)
1533 (output-object (sb!c::debug-info-name dinfo) stream)))))))
1535 (defun output-lra (lra stream)
1536 (print-unreadable-object (lra stream :identity t)
1537 (write-string "return PC object" stream)))
1539 (defun output-fdefn (fdefn stream)
1540 (print-unreadable-object (fdefn stream)
1541 (write-string "FDEFINITION object for " stream)
1542 (output-object (fdefn-name fdefn) stream)))
1546 ;;; Output OBJECT as using PRINT-OBJECT if it's a
1547 ;;; FUNCALLABLE-STANDARD-CLASS, or return NIL otherwise.
1549 ;;; The definition here is a simple temporary placeholder. It will be
1550 ;;; overwritten by a smarter version (capable of calling generic
1551 ;;; PRINT-OBJECT when appropriate) when CLOS is installed.
1552 (defun printed-as-clos-funcallable-standard-class (object stream)
1553 (declare (ignore object stream))
1556 (defun output-function (object stream)
1557 (let* ((*print-length* 3) ; in case we have to..
1558 (*print-level* 3) ; ..print an interpreted function definition
1559 (name (cond ((find (function-subtype object)
1560 #(#.sb!vm:closure-header-type
1561 #.sb!vm:byte-code-closure-type))
1563 ((sb!eval::interpreted-function-p object)
1564 (or (sb!eval::interpreted-function-%name object)
1565 (sb!eval:interpreted-function-lambda-expression
1567 ((find (function-subtype object)
1568 #(#.sb!vm:function-header-type
1569 #.sb!vm:closure-function-header-type))
1570 (%function-name object))
1571 (t 'no-name-available)))
1572 (identified-by-name-p (and (symbolp name)
1574 (eq (fdefinition name) object))))
1575 (print-unreadable-object (object
1577 :identity (not identified-by-name-p))
1578 (prin1 'function stream)
1579 (unless (eq name 'no-name-available)
1580 (format stream " ~S" name)))))
1582 ;;;; catch-all for unknown things
1584 (defun output-random (object stream)
1585 (print-unreadable-object (object stream :identity t)
1586 (let ((lowtag (get-lowtag object)))
1588 (#.sb!vm:other-pointer-type
1589 (let ((type (get-type object)))
1591 (#.sb!vm:value-cell-header-type
1592 (write-string "value cell " stream)
1593 (output-object (sb!c:value-cell-ref object) stream))
1595 (write-string "unknown pointer object, type=" stream)
1596 (let ((*print-base* 16) (*print-radix* t))
1597 (output-integer type stream))))))
1598 ((#.sb!vm:function-pointer-type
1599 #.sb!vm:instance-pointer-type
1600 #.sb!vm:list-pointer-type)
1601 (write-string "unknown pointer object, type=" stream))
1603 (case (get-type object)
1604 (#.sb!vm:unbound-marker-type
1605 (write-string "unbound marker" stream))
1607 (write-string "unknown immediate object, lowtag=" stream)
1608 (let ((*print-base* 2) (*print-radix* t))
1609 (output-integer lowtag stream))
1610 (write-string ", type=" stream)
1611 (let ((*print-base* 16) (*print-radix* t))
1612 (output-integer (get-type object) stream)))))))))