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 "Output OBJECT to the specified stream, defaulting to *STANDARD-OUTPUT*"
152 (output-object object (out-synonym-of stream))
155 (defun prin1 (object &optional stream)
157 "Output 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 "Output 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 "Output a newline, the mostly READable printed representation 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 output 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 "Return the printed representation of OBJECT as a string."
212 (stringify-object object))
214 (defun prin1-to-string (object)
216 "Return the printed representation of OBJECT as a string with
218 (stringify-object object t))
220 (defun princ-to-string (object)
222 "Return 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 ;;; Check to see whether OBJECT is a circular reference, and return something
292 ;;; non-NIL if it is. If ASSIGN is T, then the number to use in the #n= and
293 ;;; #n# noise is assigned at this time. Note: CHECK-FOR-CIRCULARITY must
294 ;;; be called *EXACTLY* once with ASSIGN T, or the circularity detection noise
295 ;;; will get confused about when to use #n= and when to use #n#. If this
296 ;;; returns non-NIL when ASSIGN is T, then you must call HANDLE-CIRCULARITY
297 ;;; on it. If you are not using this inside a WITH-CIRCULARITY-DETECTION,
298 ;;; then you have to be prepared to handle a return value of :INITIATE which
299 ;;; means it needs to initiate the circularity detection noise. See the
300 ;;; source for info on how to do that.
301 (defun check-for-circularity (object &optional assign)
302 (cond ((null *print-circle*)
303 ;; Don't bother, nobody cares.
305 ((null *circularity-hash-table*)
307 ((null *circularity-counter*)
308 (ecase (gethash object *circularity-hash-table*)
311 (setf (gethash object *circularity-hash-table*) t)
312 ;; We need to keep looking.
316 (setf (gethash object *circularity-hash-table*) 0)
317 ;; It's a circular reference.
320 ;; It's a circular reference.
323 (let ((value (gethash object *circularity-hash-table*)))
326 ;; If NIL, we found an object that wasn't there the first time
327 ;; around. If T, exactly one occurance of this object appears.
328 ;; Either way, just print the thing without any special
329 ;; processing. Note: you might argue that finding a new object
330 ;; means that something is broken, but this can happen. If
331 ;; someone uses the ~@<...~:> format directive, it conses a
332 ;; new list each time though format (i.e. the &REST list), so
333 ;; we will have different cdrs.
337 (let ((value (incf *circularity-counter*)))
338 ;; First occurance of this object. Set the counter.
339 (setf (gethash object *circularity-hash-table*) value)
343 ;; Second or later occurance.
346 ;;; Handle the results of CHECK-FOR-CIRCULARITY. If this returns T then
347 ;;; you should go ahead and print the object. If it returns NIL, then
348 ;;; you should blow it off.
349 (defun handle-circularity (marker stream)
352 ;; Someone forgot to initiate circularity detection.
353 (let ((*print-circle* nil))
354 (error "trying to use CHECK-FOR-CIRCULARITY when ~
355 circularity checking isn't initiated")))
357 ;; It's a second (or later) reference to the object while we are
358 ;; just looking. So don't bother groveling it again.
361 (write-char #\# stream)
362 (let ((*print-base* 10) (*print-radix* nil))
363 (cond ((minusp marker)
364 (output-integer (- marker) stream)
365 (write-char #\# stream)
368 (output-integer marker stream)
369 (write-char #\= stream)
372 ;;;; OUTPUT-OBJECT -- the main entry point
374 ;;; the current pretty printer. This should be either a function that
375 ;;; takes two arguments (the object and the stream) or NIL to indicate
376 ;;; that there is no pretty printer installed.
377 (defvar *pretty-printer* nil)
379 ;;; Output OBJECT to STREAM observing all printer control variables.
380 (defun output-object (object stream)
381 (labels ((print-it (stream)
384 (funcall *pretty-printer* object stream)
385 (let ((*print-pretty* nil))
386 (output-ugly-object object stream)))
387 (output-ugly-object object stream)))
389 (let ((marker (check-for-circularity object t)))
392 (let ((*circularity-hash-table*
393 (make-hash-table :test 'eq)))
394 (check-it (make-broadcast-stream))
395 (let ((*circularity-counter* 0))
400 (when (handle-circularity marker stream)
401 (print-it stream)))))))
402 (cond ((or (not *print-circle*)
405 (and (symbolp object) (symbol-package object) t))
406 ;; If it a number, character, or interned symbol, we do not
407 ;; want to check for circularity/sharing.
409 ((or *circularity-hash-table*
411 (typep object 'instance)
412 (typep object '(array t *)))
413 ;; If we have already started circularity detection, this
414 ;; object might be a sharded reference. If we have not,
415 ;; then if it is a cons, a instance, or an array of element
416 ;; type t it might contain a circular reference to itself
417 ;; or multiple shared references.
420 (print-it stream)))))
422 ;;; Output OBJECT to STREAM observing all printer control variables
423 ;;; except for *PRINT-PRETTY*. Note: if *PRINT-PRETTY* is non-NIL,
424 ;;; then the pretty printer will be used for any components of OBJECT,
425 ;;; just not for OBJECT itself.
426 (defun output-ugly-object (object stream)
428 ;; KLUDGE: The TYPECASE approach here is non-ANSI; the ANSI definition of
429 ;; PRINT-OBJECT says it provides printing and we're supposed to provide
430 ;; PRINT-OBJECT methods covering all classes. We deviate from this
431 ;; by using PRINT-OBJECT only when we print instance values. However,
432 ;; ANSI makes it hard to tell that we're deviating from this:
433 ;; (1) ANSI specifies that the user isn't supposed to call PRINT-OBJECT
435 ;; (2) ANSI (section 11.1.2.1.2) says it's undefined to define
436 ;; a method on an external symbol in the CL package which is
437 ;; applicable to arg lists containing only direct instances of
438 ;; standardized classes.
439 ;; Thus, in order for the user to detect our sleaziness, he has to do
440 ;; something relatively obscure like
441 ;; (1) actually use tools like FIND-METHOD to look for PRINT-OBJECT
443 ;; (2) define a PRINT-OBJECT method which is specialized on the stream
444 ;; value (e.g. a Gray stream object).
445 ;; As long as no one comes up with a non-obscure way of detecting this
446 ;; sleaziness, fixing this nonconformity will probably have a low
447 ;; priority. -- WHN 20000121
449 (output-integer object stream))
452 (output-symbol object stream)
453 (output-list object stream)))
455 (print-object object stream))
457 (unless (and (funcallable-instance-p object)
458 (printed-as-funcallable-standard-class object stream))
459 (output-function object stream)))
461 (output-symbol object stream))
465 (output-integer object stream))
467 (output-float object stream))
469 (output-ratio object stream))
471 (output-ratio object stream))
473 (output-complex object stream))))
475 (output-character object stream))
477 (output-vector object stream))
479 (output-array object stream))
481 (output-sap object stream))
483 (output-weak-pointer object stream))
485 (output-lra object stream))
487 (output-code-component object stream))
489 (output-fdefn object stream))
491 (output-random object stream))))
495 ;;; Values of *PRINT-CASE* and (READTABLE-CASE *READTABLE*) the last
496 ;;; time the printer was called.
497 (defvar *previous-case* nil)
498 (defvar *previous-readtable-case* nil)
500 ;;; This variable contains the current definition of one of three
501 ;;; symbol printers. SETUP-PRINTER-STATE sets this variable.
502 (defvar *internal-symbol-output-function* nil)
504 ;;; This function sets the internal global symbol
505 ;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION* to the right function depending
506 ;;; on the value of *PRINT-CASE*. See the manual for details. The
507 ;;; print buffer stream is also reset.
508 (defun setup-printer-state ()
509 (unless (and (eq *print-case* *previous-case*)
510 (eq (readtable-case *readtable*) *previous-readtable-case*))
511 (setq *previous-case* *print-case*)
512 (setq *previous-readtable-case* (readtable-case *readtable*))
513 (unless (member *print-case* '(:upcase :downcase :capitalize))
514 (setq *print-case* :upcase)
515 (error "invalid *PRINT-CASE* value: ~S" *previous-case*))
516 (unless (member *previous-readtable-case*
517 '(:upcase :downcase :invert :preserve))
518 (setf (readtable-case *readtable*) :upcase)
519 (error "invalid READTABLE-CASE value: ~S" *previous-readtable-case*))
521 (setq *internal-symbol-output-function*
522 (case *previous-readtable-case*
525 (:upcase #'output-preserve-symbol)
526 (:downcase #'output-lowercase-symbol)
527 (:capitalize #'output-capitalize-symbol)))
530 (:upcase #'output-uppercase-symbol)
531 (:downcase #'output-preserve-symbol)
532 (:capitalize #'output-capitalize-symbol)))
533 (:preserve #'output-preserve-symbol)
534 (:invert #'output-invert-symbol)))))
536 ;;; Output PNAME (a symbol-name or package-name) surrounded with |'s,
537 ;;; and with any embedded |'s or \'s escaped.
538 (defun output-quoted-symbol-name (pname stream)
539 (write-char #\| stream)
540 (dotimes (index (length pname))
541 (let ((char (schar pname index)))
542 (when (or (char= char #\\) (char= char #\|))
543 (write-char #\\ stream))
544 (write-char char stream)))
545 (write-char #\| stream))
547 (defun output-symbol (object stream)
548 (if (or *print-escape* *print-readably*)
549 (let ((package (symbol-package object))
550 (name (symbol-name object)))
552 ;; The ANSI spec "22.1.3.3.1 Package Prefixes for Symbols"
553 ;; requires that keywords be printed with preceding colons
554 ;; always, regardless of the value of *PACKAGE*.
555 ((eq package *keyword-package*)
556 (write-char #\: stream))
557 ;; Otherwise, if the symbol's home package is the current
558 ;; one, then a prefix is never necessary.
559 ((eq package (sane-package)))
560 ;; Uninterned symbols print with a leading #:.
562 (when (or *print-gensym* *print-readably*)
563 (write-string "#:" stream)))
565 (multiple-value-bind (symbol accessible)
566 (find-symbol name (sane-package))
567 ;; If we can find the symbol by looking it up, it need not
568 ;; be qualified. This can happen if the symbol has been
569 ;; inherited from a package other than its home package.
570 (unless (and accessible (eq symbol object))
571 (output-symbol-name (package-name package) stream)
572 (multiple-value-bind (symbol externalp)
573 (find-external-symbol name package)
574 (declare (ignore symbol))
576 (write-char #\: stream)
577 (write-string "::" stream)))))))
578 (output-symbol-name name stream))
579 (output-symbol-name (symbol-name object) stream nil)))
581 ;;; Output the string NAME as if it were a symbol name. In other
582 ;;; words, diddle its case according to *PRINT-CASE* and
584 (defun output-symbol-name (name stream &optional (maybe-quote t))
585 (declare (type simple-base-string name))
586 (setup-printer-state)
587 (if (and maybe-quote (symbol-quotep name))
588 (output-quoted-symbol-name name stream)
589 (funcall *internal-symbol-output-function* name stream)))
591 ;;;; escaping symbols
593 ;;; When we print symbols we have to figure out if they need to be
594 ;;; printed with escape characters. This isn't a whole lot easier than
595 ;;; reading symbols in the first place.
597 ;;; For each character, the value of the corresponding element is a
598 ;;; fixnum with bits set corresponding to attributes that the
599 ;;; character has. At characters have at least one bit set, so we can
600 ;;; search for any character with a positive test.
601 (defvar *character-attributes*
602 (make-array char-code-limit
603 :element-type '(unsigned-byte 16)
605 (declaim (type (simple-array (unsigned-byte 16) (#.char-code-limit))
606 *character-attributes*))
608 ;;; constants which are a bit-mask for each interesting character attribute
609 (defconstant other-attribute (ash 1 0)) ; Anything else legal.
610 (defconstant number-attribute (ash 1 1)) ; A numeric digit.
611 (defconstant uppercase-attribute (ash 1 2)) ; An uppercase letter.
612 (defconstant lowercase-attribute (ash 1 3)) ; A lowercase letter.
613 (defconstant sign-attribute (ash 1 4)) ; +-
614 (defconstant extension-attribute (ash 1 5)) ; ^_
615 (defconstant dot-attribute (ash 1 6)) ; .
616 (defconstant slash-attribute (ash 1 7)) ; /
617 (defconstant funny-attribute (ash 1 8)) ; Anything illegal.
619 (eval-when (:compile-toplevel :load-toplevel :execute)
621 ;;; LETTER-ATTRIBUTE is a local of SYMBOL-QUOTEP. It matches letters
622 ;;; that don't need to be escaped (according to READTABLE-CASE.)
623 (defparameter *attribute-names*
624 `((number . number-attribute) (lowercase . lowercase-attribute)
625 (uppercase . uppercase-attribute) (letter . letter-attribute)
626 (sign . sign-attribute) (extension . extension-attribute)
627 (dot . dot-attribute) (slash . slash-attribute)
628 (other . other-attribute) (funny . funny-attribute)))
632 (flet ((set-bit (char bit)
633 (let ((code (char-code char)))
634 (setf (aref *character-attributes* code)
635 (logior bit (aref *character-attributes* code))))))
637 (dolist (char '(#\! #\@ #\$ #\% #\& #\* #\= #\~ #\[ #\] #\{ #\}
639 (set-bit char other-attribute))
642 (set-bit (digit-char i) number-attribute))
644 (do ((code (char-code #\A) (1+ code))
645 (end (char-code #\Z)))
647 (declare (fixnum code end))
648 (set-bit (code-char code) uppercase-attribute)
649 (set-bit (char-downcase (code-char code)) lowercase-attribute))
651 (set-bit #\- sign-attribute)
652 (set-bit #\+ sign-attribute)
653 (set-bit #\^ extension-attribute)
654 (set-bit #\_ extension-attribute)
655 (set-bit #\. dot-attribute)
656 (set-bit #\/ slash-attribute)
658 ;; Mark anything not explicitly allowed as funny.
659 (dotimes (i char-code-limit)
660 (when (zerop (aref *character-attributes* i))
661 (setf (aref *character-attributes* i) funny-attribute))))
663 ;;; For each character, the value of the corresponding element is the
664 ;;; lowest base in which that character is a digit.
665 (defvar *digit-bases*
666 (make-array char-code-limit
667 :element-type '(unsigned-byte 8)
668 :initial-element 36))
669 (declaim (type (simple-array (unsigned-byte 8) (#.char-code-limit))
673 (let ((char (digit-char i 36)))
674 (setf (aref *digit-bases* (char-code char)) i)))
676 ;;; A FSM-like thingie that determines whether a symbol is a potential
677 ;;; number or has evil characters in it.
678 (defun symbol-quotep (name)
679 (declare (simple-string name))
680 (macrolet ((advance (tag &optional (at-end t))
683 ,(if at-end '(go TEST-SIGN) '(return nil)))
684 (setq current (schar name index)
685 code (char-code current)
686 bits (aref attributes code))
689 (test (&rest attributes)
701 `(< (the fixnum (aref bases code)) base)))
703 (prog ((len (length name))
704 (attributes *character-attributes*)
705 (bases *digit-bases*)
708 (case (readtable-case *readtable*)
709 (:upcase uppercase-attribute)
710 (:downcase lowercase-attribute)
711 (t (logior lowercase-attribute uppercase-attribute))))
716 (declare (fixnum len base index bits code))
719 TEST-SIGN ; At end, see whether it is a sign...
720 (return (not (test sign)))
722 OTHER ; not potential number, see whether funny chars...
723 (let ((mask (logxor (logior lowercase-attribute uppercase-attribute
726 (do ((i (1- index) (1+ i)))
727 ((= i len) (return-from symbol-quotep nil))
728 (unless (zerop (logand (aref attributes (char-code (schar name i)))
730 (return-from symbol-quotep t))))
735 (advance LAST-DIGIT-ALPHA)
737 (when (test letter number other slash) (advance OTHER nil))
738 (when (char= current #\.) (advance DOT-FOUND))
739 (when (test sign extension) (advance START-STUFF nil))
742 DOT-FOUND ; leading dots...
743 (when (test letter) (advance START-DOT-MARKER nil))
744 (when (digitp) (advance DOT-DIGIT))
745 (when (test number other) (advance OTHER nil))
746 (when (test extension slash sign) (advance START-DOT-STUFF nil))
747 (when (char= current #\.) (advance DOT-FOUND))
750 START-STUFF ; leading stuff before any dot or digit
753 (advance LAST-DIGIT-ALPHA)
755 (when (test number other) (advance OTHER nil))
756 (when (test letter) (advance START-MARKER nil))
757 (when (char= current #\.) (advance START-DOT-STUFF nil))
758 (when (test sign extension slash) (advance START-STUFF nil))
761 START-MARKER ; number marker in leading stuff...
762 (when (test letter) (advance OTHER nil))
765 START-DOT-STUFF ; leading stuff containing dot without digit...
766 (when (test letter) (advance START-DOT-STUFF nil))
767 (when (digitp) (advance DOT-DIGIT))
768 (when (test sign extension dot slash) (advance START-DOT-STUFF nil))
769 (when (test number other) (advance OTHER nil))
772 START-DOT-MARKER ; number marker in leading stuff with dot..
773 ;; leading stuff containing dot without digit followed by letter...
774 (when (test letter) (advance OTHER nil))
777 DOT-DIGIT ; in a thing with dots...
778 (when (test letter) (advance DOT-MARKER))
779 (when (digitp) (advance DOT-DIGIT))
780 (when (test number other) (advance OTHER nil))
781 (when (test sign extension dot slash) (advance DOT-DIGIT))
784 DOT-MARKER ; number marker in number with dot...
785 (when (test letter) (advance OTHER nil))
788 LAST-DIGIT-ALPHA ; previous char is a letter digit...
789 (when (or (digitp) (test sign slash))
790 (advance ALPHA-DIGIT))
791 (when (test letter number other dot) (advance OTHER nil))
794 ALPHA-DIGIT ; seen a digit which is a letter...
795 (when (or (digitp) (test sign slash))
797 (advance LAST-DIGIT-ALPHA)
798 (advance ALPHA-DIGIT)))
799 (when (test letter) (advance ALPHA-MARKER))
800 (when (test number other dot) (advance OTHER nil))
803 ALPHA-MARKER ; number marker in number with alpha digit...
804 (when (test letter) (advance OTHER nil))
807 DIGIT ; seen only ordinary (non-alphabetic) numeric digits...
810 (advance ALPHA-DIGIT)
812 (when (test number other) (advance OTHER nil))
813 (when (test letter) (advance MARKER))
814 (when (test extension slash sign) (advance DIGIT))
815 (when (char= current #\.) (advance DOT-DIGIT))
818 MARKER ; number marker in a numeric number...
819 (when (test letter) (advance OTHER nil))
822 ;;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION*
824 ;;;; Case hackery. These functions are stored in
825 ;;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION* according to the values of
826 ;;;; *PRINT-CASE* and READTABLE-CASE.
829 ;;; READTABLE-CASE *PRINT-CASE*
831 ;;; :DOWNCASE :DOWNCASE
833 (defun output-preserve-symbol (pname stream)
834 (declare (simple-string pname))
835 (write-string pname stream))
838 ;;; READTABLE-CASE *PRINT-CASE*
839 ;;; :UPCASE :DOWNCASE
840 (defun output-lowercase-symbol (pname stream)
841 (declare (simple-string pname))
842 (dotimes (index (length pname))
843 (let ((char (schar pname index)))
844 (write-char (char-downcase char) stream))))
847 ;;; READTABLE-CASE *PRINT-CASE*
848 ;;; :DOWNCASE :UPCASE
849 (defun output-uppercase-symbol (pname stream)
850 (declare (simple-string pname))
851 (dotimes (index (length pname))
852 (let ((char (schar pname index)))
853 (write-char (char-upcase char) stream))))
856 ;;; READTABLE-CASE *PRINT-CASE*
857 ;;; :UPCASE :CAPITALIZE
858 ;;; :DOWNCASE :CAPITALIZE
859 (defun output-capitalize-symbol (pname stream)
860 (declare (simple-string pname))
861 (let ((prev-not-alpha t)
862 (up (eq (readtable-case *readtable*) :upcase)))
863 (dotimes (i (length pname))
864 (let ((char (char pname i)))
866 (if (or prev-not-alpha (lower-case-p char))
868 (char-downcase char))
873 (setq prev-not-alpha (not (alpha-char-p char)))))))
876 ;;; READTABLE-CASE *PRINT-CASE*
878 (defun output-invert-symbol (pname stream)
879 (declare (simple-string pname))
882 (dotimes (i (length pname))
883 (let ((ch (schar pname i)))
884 (when (both-case-p ch)
885 (if (upper-case-p ch)
887 (setq all-upper nil)))))
888 (cond (all-upper (output-lowercase-symbol pname stream))
889 (all-lower (output-uppercase-symbol pname stream))
891 (write-string pname stream)))))
895 (let ((*readtable* (copy-readtable nil)))
896 (format t "READTABLE-CASE Input Symbol-name~@
897 ----------------------------------~%")
898 (dolist (readtable-case '(:upcase :downcase :preserve :invert))
899 (setf (readtable-case *readtable*) readtable-case)
900 (dolist (input '("ZEBRA" "Zebra" "zebra"))
901 (format t "~&:~A~16T~A~24T~A"
902 (string-upcase readtable-case)
904 (symbol-name (read-from-string input)))))))
907 (let ((*readtable* (copy-readtable nil)))
908 (format t "READTABLE-CASE *PRINT-CASE* Symbol-name Output Princ~@
909 --------------------------------------------------------~%")
910 (dolist (readtable-case '(:upcase :downcase :preserve :invert))
911 (setf (readtable-case *readtable*) readtable-case)
912 (dolist (*print-case* '(:upcase :downcase :capitalize))
913 (dolist (symbol '(|ZEBRA| |Zebra| |zebra|))
914 (format t "~&:~A~15T:~A~29T~A~42T~A~50T~A"
915 (string-upcase readtable-case)
916 (string-upcase *print-case*)
918 (prin1-to-string symbol)
919 (princ-to-string symbol)))))))
922 ;;;; recursive objects
924 (defun output-list (list stream)
925 (descend-into (stream)
926 (write-char #\( stream)
930 (punt-print-if-too-long length stream)
931 (output-object (pop list) stream)
934 (when (or (atom list) (check-for-circularity list))
935 (write-string " . " stream)
936 (output-object list stream)
938 (write-char #\space stream)
940 (write-char #\) stream)))
942 (defun output-vector (vector stream)
943 (declare (vector vector))
944 (cond ((stringp vector)
945 (cond ((or *print-escape* *print-readably*)
946 (write-char #\" stream)
947 (quote-string vector stream)
948 (write-char #\" stream))
950 (write-string vector stream))))
951 ((not (or *print-array* *print-readably*))
952 (output-terse-array vector stream))
953 ((bit-vector-p vector)
954 (write-string "#*" stream)
955 (dovector (bit vector)
956 ;; (Don't use OUTPUT-OBJECT here, since this code
957 ;; has to work for all possible *PRINT-BASE* values.)
958 (write-char (if (zerop bit) #\0 #\1) stream)))
960 (when (and *print-readably*
961 (not (eq (array-element-type vector) t)))
962 (error 'print-not-readable :object vector))
963 (descend-into (stream)
964 (write-string "#(" stream)
965 (dotimes (i (length vector))
967 (write-char #\space stream))
968 (punt-print-if-too-long i stream)
969 (output-object (aref vector i) stream))
970 (write-string ")" stream)))))
972 ;;; This function outputs a string quoting characters sufficiently
973 ;;; so that someone can read it in again. Basically, put a slash in
974 ;;; front of an character satisfying NEEDS-SLASH-P.
975 (defun quote-string (string stream)
976 (macrolet ((needs-slash-p (char)
977 ;; KLUDGE: We probably should look at the readtable, but just do
978 ;; this for now. [noted by anonymous long ago] -- WHN 19991130
979 `(or (char= ,char #\\)
981 (with-array-data ((data string) (start) (end (length string)))
982 (do ((index start (1+ index)))
984 (let ((char (schar data index)))
985 (when (needs-slash-p char) (write-char #\\ stream))
986 (write-char char stream))))))
988 ;;; Output the printed representation of any array in either the #< or #A
990 (defun output-array (array stream)
991 (if (or *print-array* *print-readably*)
992 (output-array-guts array stream)
993 (output-terse-array array stream)))
995 ;;; Output the abbreviated #< form of an array.
996 (defun output-terse-array (array stream)
997 (let ((*print-level* nil)
998 (*print-length* nil))
999 (print-unreadable-object (array stream :type t :identity t))))
1001 ;;; Output the readable #A form of an array.
1002 (defun output-array-guts (array stream)
1003 (when (and *print-readably*
1004 (not (eq (array-element-type array) t)))
1005 (error 'print-not-readable :object array))
1006 (write-char #\# stream)
1007 (let ((*print-base* 10))
1008 (output-integer (array-rank array) stream))
1009 (write-char #\A stream)
1010 (with-array-data ((data array) (start) (end))
1011 (declare (ignore end))
1012 (sub-output-array-guts data (array-dimensions array) stream start)))
1014 (defun sub-output-array-guts (array dimensions stream index)
1015 (declare (type (simple-array * (*)) array) (fixnum index))
1016 (cond ((null dimensions)
1017 (output-object (aref array index) stream))
1019 (descend-into (stream)
1020 (write-char #\( stream)
1021 (let* ((dimension (car dimensions))
1022 (dimensions (cdr dimensions))
1023 (count (reduce #'* dimensions)))
1024 (dotimes (i dimension)
1026 (write-char #\space stream))
1027 (punt-print-if-too-long i stream)
1028 (sub-output-array-guts array dimensions stream index)
1029 (incf index count)))
1030 (write-char #\) stream)))))
1032 ;;; a trivial non-generic-function placeholder for PRINT-OBJECT, for
1033 ;;; use until CLOS is set up (at which time it will be replaced with
1034 ;;; the real generic function implementation)
1035 (defun print-object (instance stream)
1036 (default-structure-print instance stream *current-level*))
1038 ;;;; integer, ratio, and complex printing (i.e. everything but floats)
1040 (defun output-integer (integer stream)
1041 ;; FIXME: This UNLESS form should be pulled out into something like
1042 ;; (SANE-PRINT-BASE), along the lines of (SANE-PACKAGE) for the
1043 ;; *PACKAGE* variable.
1044 (unless (and (fixnump *print-base*)
1045 (< 1 *print-base* 37))
1046 (let ((obase *print-base*))
1047 (setq *print-base* 10.)
1048 (error "~A is not a reasonable value for *PRINT-BASE*." obase)))
1049 (when (and (not (= *print-base* 10.))
1051 ;; First print leading base information, if any.
1052 (write-char #\# stream)
1053 (write-char (case *print-base*
1057 (T (let ((fixbase *print-base*)
1060 (sub-output-integer fixbase stream))
1063 ;; Then output a minus sign if the number is negative, then output
1064 ;; the absolute value of the number.
1065 (cond ((bignump integer) (print-bignum integer stream))
1067 (write-char #\- stream)
1068 (sub-output-integer (- integer) stream))
1070 (sub-output-integer integer stream)))
1071 ;; Print any trailing base information, if any.
1072 (if (and (= *print-base* 10.) *print-radix*)
1073 (write-char #\. stream)))
1075 (defun sub-output-integer (integer stream)
1078 ;; Recurse until you have all the digits pushed on the stack.
1079 (if (not (zerop (multiple-value-setq (quotient remainder)
1080 (truncate integer *print-base*))))
1081 (sub-output-integer quotient stream))
1082 ;; Then as each recursive call unwinds, turn the digit (in remainder)
1083 ;; into a character and output the character.
1084 (write-char (code-char (if (and (> remainder 9.)
1085 (> *print-base* 10.))
1086 (+ (char-code #\A) (- remainder 10.))
1087 (+ (char-code #\0) remainder)))
1090 ;;;; bignum printing
1092 ;;; *BASE-POWER* holds the number that we keep dividing into the
1093 ;;; bignum for each *print-base*. We want this number as close to
1094 ;;; *most-positive-fixnum* as possible, i.e. (floor (log
1095 ;;; most-positive-fixnum *print-base*)).
1096 (defparameter *base-power* (make-array 37 :initial-element nil))
1098 ;;; *FIXNUM-POWER--1* holds the number of digits for each *PRINT-BASE*
1099 ;;; that fit in the corresponding *base-power*.
1100 (defparameter *fixnum-power--1* (make-array 37 :initial-element nil))
1102 ;;; Print the bignum to the stream. We first generate the correct
1103 ;;; value for *base-power* and *fixnum-power--1* if we have not
1104 ;;; already. Then we call bignum-print-aux to do the printing.
1105 (defun print-bignum (big stream)
1106 (unless (aref *base-power* *print-base*)
1107 (do ((power-1 -1 (1+ power-1))
1108 (new-divisor *print-base* (* new-divisor *print-base*))
1109 (divisor 1 new-divisor))
1110 ((not (fixnump new-divisor))
1111 (setf (aref *base-power* *print-base*) divisor)
1112 (setf (aref *fixnum-power--1* *print-base*) power-1))))
1113 (bignum-print-aux (cond ((minusp big)
1114 (write-char #\- stream)
1117 (aref *base-power* *print-base*)
1118 (aref *fixnum-power--1* *print-base*)
1122 (defun bignum-print-aux (big divisor power-1 stream)
1123 (multiple-value-bind (newbig fix) (truncate big divisor)
1124 (if (fixnump newbig)
1125 (sub-output-integer newbig stream)
1126 (bignum-print-aux newbig divisor power-1 stream))
1127 (do ((zeros power-1 (1- zeros))
1128 (base-power *print-base* (* base-power *print-base*)))
1130 (dotimes (i zeros) (write-char #\0 stream))
1131 (sub-output-integer fix stream)))))
1133 (defun output-ratio (ratio stream)
1135 (write-char #\# stream)
1137 (2 (write-char #\b stream))
1138 (8 (write-char #\o stream))
1139 (16 (write-char #\x stream))
1140 (t (write *print-base* :stream stream :radix nil :base 10)))
1141 (write-char #\r stream))
1142 (let ((*print-radix* nil))
1143 (output-integer (numerator ratio) stream)
1144 (write-char #\/ stream)
1145 (output-integer (denominator ratio) stream)))
1147 (defun output-complex (complex stream)
1148 (write-string "#C(" stream)
1149 (output-object (realpart complex) stream)
1150 (write-char #\space stream)
1151 (output-object (imagpart complex) stream)
1152 (write-char #\) stream))
1156 ;;; FLONUM-TO-STRING (and its subsidiary function FLOAT-STRING) does
1157 ;;; most of the work for all printing of floating point numbers in the
1158 ;;; printer and in FORMAT. It converts a floating point number to a
1159 ;;; string in a free or fixed format with no exponent. The
1160 ;;; interpretation of the arguments is as follows:
1162 ;;; X - The floating point number to convert, which must not be
1164 ;;; WIDTH - The preferred field width, used to determine the number
1165 ;;; of fraction digits to produce if the FDIGITS parameter
1166 ;;; is unspecified or NIL. If the non-fraction digits and the
1167 ;;; decimal point alone exceed this width, no fraction digits
1168 ;;; will be produced unless a non-NIL value of FDIGITS has been
1169 ;;; specified. Field overflow is not considerd an error at this
1171 ;;; FDIGITS - The number of fractional digits to produce. Insignificant
1172 ;;; trailing zeroes may be introduced as needed. May be
1173 ;;; unspecified or NIL, in which case as many digits as possible
1174 ;;; are generated, subject to the constraint that there are no
1175 ;;; trailing zeroes.
1176 ;;; SCALE - If this parameter is specified or non-NIL, then the number
1177 ;;; printed is (* x (expt 10 scale)). This scaling is exact,
1178 ;;; and cannot lose precision.
1179 ;;; FMIN - This parameter, if specified or non-NIL, is the minimum
1180 ;;; number of fraction digits which will be produced, regardless
1181 ;;; of the value of WIDTH or FDIGITS. This feature is used by
1182 ;;; the ~E format directive to prevent complete loss of
1183 ;;; significance in the printed value due to a bogus choice of
1186 ;;; Most of the optional arguments are for the benefit for FORMAT and are not
1187 ;;; used by the printer.
1190 ;;; (VALUES DIGIT-STRING DIGIT-LENGTH LEADING-POINT TRAILING-POINT DECPNT)
1191 ;;; where the results have the following interpretation:
1193 ;;; DIGIT-STRING - The decimal representation of X, with decimal point.
1194 ;;; DIGIT-LENGTH - The length of the string DIGIT-STRING.
1195 ;;; LEADING-POINT - True if the first character of DIGIT-STRING is the
1197 ;;; TRAILING-POINT - True if the last character of DIGIT-STRING is the
1199 ;;; POINT-POS - The position of the digit preceding the decimal
1200 ;;; point. Zero indicates point before first digit.
1202 ;;; NOTE: FLONUM-TO-STRING goes to a lot of trouble to guarantee
1203 ;;; accuracy. Specifically, the decimal number printed is the closest
1204 ;;; possible approximation to the true value of the binary number to
1205 ;;; be printed from among all decimal representations with the same
1206 ;;; number of digits. In free-format output, i.e. with the number of
1207 ;;; digits unconstrained, it is guaranteed that all the information is
1208 ;;; preserved, so that a properly- rounding reader can reconstruct the
1209 ;;; original binary number, bit-for-bit, from its printed decimal
1210 ;;; representation. Furthermore, only as many digits as necessary to
1211 ;;; satisfy this condition will be printed.
1213 ;;; FLOAT-STRING actually generates the digits for positive numbers.
1214 ;;; The algorithm is essentially that of algorithm Dragon4 in "How to
1215 ;;; Print Floating-Point Numbers Accurately" by Steele and White. The
1216 ;;; current (draft) version of this paper may be found in
1217 ;;; [CMUC]<steele>tradix.press. DO NOT EVEN THINK OF ATTEMPTING TO
1218 ;;; UNDERSTAND THIS CODE WITHOUT READING THE PAPER!
1220 (defvar *digits* "0123456789")
1222 (defun flonum-to-string (x &optional width fdigits scale fmin)
1224 ;; Zero is a special case which FLOAT-STRING cannot handle.
1226 (let ((s (make-string (1+ fdigits) :initial-element #\0)))
1227 (setf (schar s 0) #\.)
1228 (values s (length s) t (zerop fdigits) 0))
1229 (values "." 1 t t 0)))
1231 (multiple-value-bind (sig exp) (integer-decode-float x)
1232 (let* ((precision (float-precision x))
1233 (digits (float-digits x))
1234 (fudge (- digits precision))
1235 (width (if width (max width 1) nil)))
1236 (float-string (ash sig (- fudge)) (+ exp fudge) precision width
1237 fdigits scale fmin))))))
1239 (defun float-string (fraction exponent precision width fdigits scale fmin)
1240 (let ((r fraction) (s 1) (m- 1) (m+ 1) (k 0)
1241 (digits 0) (decpnt 0) (cutoff nil) (roundup nil) u low high
1242 (digit-string (make-array 50
1243 :element-type 'base-char
1246 ;; Represent fraction as r/s, error bounds as m+/s and m-/s.
1247 ;; Rational arithmetic avoids loss of precision in subsequent
1249 (cond ((> exponent 0)
1250 (setq r (ash fraction exponent))
1251 (setq m- (ash 1 exponent))
1254 (setq s (ash 1 (- exponent)))))
1255 ;; Adjust the error bounds m+ and m- for unequal gaps.
1256 (when (= fraction (ash 1 precision))
1257 (setq m+ (ash m+ 1))
1260 ;; Scale value by requested amount, and update error bounds.
1263 (let ((scale-factor (expt 10 (- scale))))
1264 (setq s (* s scale-factor)))
1265 (let ((scale-factor (expt 10 scale)))
1266 (setq r (* r scale-factor))
1267 (setq m+ (* m+ scale-factor))
1268 (setq m- (* m- scale-factor)))))
1269 ;; Scale r and s and compute initial k, the base 10 logarithm of r.
1271 ((>= r (ceiling s 10)))
1275 (setq m+ (* m+ 10)))
1278 ((< (+ (ash r 1) m+) (ash s 1)))
1281 ;; Determine number of fraction digits to generate.
1283 ;; Use specified number of fraction digits.
1284 (setq cutoff (- fdigits))
1285 ;;don't allow less than fmin fraction digits
1286 (if (and fmin (> cutoff (- fmin))) (setq cutoff (- fmin))))
1288 ;; Use as many fraction digits as width will permit but
1289 ;; force at least fmin digits even if width will be
1292 (setq cutoff (- 1 width))
1293 (setq cutoff (1+ (- k width))))
1294 (if (and fmin (> cutoff (- fmin))) (setq cutoff (- fmin)))))
1295 ;; If we decided to cut off digit generation before precision
1296 ;; has been exhausted, rounding the last digit may cause a carry
1297 ;; propagation. We can prevent this, preserving left-to-right
1298 ;; digit generation, with a few magical adjustments to m- and
1299 ;; m+. Of course, correct rounding is also preserved.
1300 (when (or fdigits width)
1301 (let ((a (- cutoff k))
1304 (dotimes (i a) (setq y (* y 10)))
1305 (dotimes (i (- a)) (setq y (ceiling y 10))))
1306 (setq m- (max y m-))
1307 (setq m+ (max y m+))
1308 (when (= m+ y) (setq roundup t))))
1309 (when (< (+ (ash r 1) m+) (ash s 1)) (return)))
1310 ;; Zero-fill before fraction if no integer part.
1312 (setq decpnt digits)
1313 (vector-push-extend #\. digit-string)
1315 (incf digits) (vector-push-extend #\0 digit-string)))
1316 ;; Generate the significant digits.
1320 (vector-push-extend #\. digit-string)
1321 (setq decpnt digits))
1322 (multiple-value-setq (u r) (truncate (* r 10) s))
1325 (setq low (< (ash r 1) m-))
1327 (setq high (>= (ash r 1) (- (ash s 1) m+)))
1328 (setq high (> (ash r 1) (- (ash s 1) m+))))
1329 ;; Stop when either precision is exhausted or we have printed as
1330 ;; many fraction digits as permitted.
1331 (when (or low high (and cutoff (<= k cutoff))) (return))
1332 (vector-push-extend (char *digits* u) digit-string)
1334 ;; If cutoff occurred before first digit, then no digits are
1335 ;; generated at all.
1336 (when (or (not cutoff) (>= k cutoff))
1337 ;; Last digit may need rounding
1338 (vector-push-extend (char *digits*
1339 (cond ((and low (not high)) u)
1340 ((and high (not low)) (1+ u))
1341 (t (if (<= (ash r 1) s) u (1+ u)))))
1344 ;; Zero-fill after integer part if no fraction.
1346 (dotimes (i k) (incf digits) (vector-push-extend #\0 digit-string))
1347 (vector-push-extend #\. digit-string)
1348 (setq decpnt digits))
1349 ;; Add trailing zeroes to pad fraction if fdigits specified.
1351 (dotimes (i (- fdigits (- digits decpnt)))
1353 (vector-push-extend #\0 digit-string)))
1355 (values digit-string (1+ digits) (= decpnt 0) (= decpnt digits) decpnt)))
1357 ;;; Given a non-negative floating point number, SCALE-EXPONENT returns
1358 ;;; a new floating point number Z in the range (0.1, 1.0] and an
1359 ;;; exponent E such that Z * 10^E is (approximately) equal to the
1360 ;;; original number. There may be some loss of precision due the
1361 ;;; floating point representation. The scaling is always done with
1362 ;;; long float arithmetic, which helps printing of lesser precisions
1363 ;;; as well as avoiding generic arithmetic.
1365 ;;; When computing our initial scale factor using EXPT, we pull out
1366 ;;; part of the computation to avoid over/under flow. When
1367 ;;; denormalized, we must pull out a large factor, since there is more
1368 ;;; negative exponent range than positive range.
1369 (defun scale-exponent (original-x)
1370 (let* ((x (coerce original-x 'long-float)))
1371 (multiple-value-bind (sig exponent) (decode-float x)
1372 (declare (ignore sig))
1374 (values (float 0.0l0 original-x) 1)
1375 (let* ((ex (round (* exponent (log 2l0 10))))
1377 (if (float-denormalized-p x)
1379 (* x 1.0l16 (expt 10.0l0 (- (- ex) 16)))
1381 (* x 1.0l18 (expt 10.0l0 (- (- ex) 18)))
1382 (* x 10.0l0 (expt 10.0l0 (- (- ex) 1))))
1383 (/ x 10.0l0 (expt 10.0l0 (1- ex))))))
1384 (do ((d 10.0l0 (* d 10.0l0))
1388 (do ((m 10.0l0 (* m 10.0l0))
1392 (values (float z original-x) ex))))))))))
1394 ;;;; entry point for the float printer
1396 ;;; the float printer as called by PRINT, PRIN1, PRINC, etc. The
1397 ;;; argument is printed free-format, in either exponential or
1398 ;;; non-exponential notation, depending on its magnitude.
1400 ;;; NOTE: When a number is to be printed in exponential format, it is
1401 ;;; scaled in floating point. Since precision may be lost in this
1402 ;;; process, the guaranteed accuracy properties of FLONUM-TO-STRING
1403 ;;; are lost. The difficulty is that FLONUM-TO-STRING performs
1404 ;;; extensive computations with integers of similar magnitude to that
1405 ;;; of the number being printed. For large exponents, the bignums
1406 ;;; really get out of hand. If bignum arithmetic becomes reasonably
1407 ;;; fast and the exponent range is not too large, then it might become
1408 ;;; attractive to handle exponential notation with the same accuracy
1409 ;;; as non-exponential notation, using the method described in the
1410 ;;; Steele and White paper.
1412 ;;; Print the appropriate exponent marker for X and the specified exponent.
1413 (defun print-float-exponent (x exp stream)
1414 (declare (type float x) (type integer exp) (type stream stream))
1415 (let ((*print-radix* nil)
1416 (plusp (plusp exp)))
1417 (if (typep x *read-default-float-format*)
1419 (format stream "e~:[~;+~]~D" plusp exp))
1420 (format stream "~C~:[~;+~]~D"
1428 (defun output-float-infinity (x stream)
1429 (declare (float x) (stream stream))
1431 (write-string "#." stream))
1433 (error 'print-not-readable :object x))
1435 (write-string "#<" stream)))
1436 (write-string "SB-EXT:" stream)
1437 (write-string (symbol-name (float-format-name x)) stream)
1438 (write-string (if (plusp x) "-POSITIVE-" "-NEGATIVE-")
1440 (write-string "INFINITY" stream)
1442 (write-string ">" stream)))
1444 (defun output-float-nan (x stream)
1445 (print-unreadable-object (x stream)
1446 (princ (float-format-name x) stream)
1447 (write-string (if (float-trapping-nan-p x) " trapping" " quiet") stream)
1448 (write-string " NaN" stream)))
1450 ;;; the function called by OUTPUT-OBJECT to handle floats
1451 (defun output-float (x stream)
1453 ((float-infinity-p x)
1454 (output-float-infinity x stream))
1456 (output-float-nan x stream))
1458 (let ((x (cond ((minusp (float-sign x))
1459 (write-char #\- stream)
1465 (write-string "0.0" stream)
1466 (print-float-exponent x 0 stream))
1468 (output-float-aux x stream (float 1/1000 x) (float 10000000 x))))))))
1469 (defun output-float-aux (x stream e-min e-max)
1470 (if (and (>= x e-min) (< x e-max))
1472 (multiple-value-bind (str len lpoint tpoint) (flonum-to-string x)
1473 (declare (ignore len))
1474 (when lpoint (write-char #\0 stream))
1475 (write-string str stream)
1476 (when tpoint (write-char #\0 stream))
1477 (print-float-exponent x 0 stream))
1478 ;; exponential format
1479 (multiple-value-bind (f ex) (scale-exponent x)
1480 (multiple-value-bind (str len lpoint tpoint)
1481 (flonum-to-string f nil nil 1)
1482 (declare (ignore len))
1483 (when lpoint (write-char #\0 stream))
1484 (write-string str stream)
1485 (when tpoint (write-char #\0 stream))
1486 ;; Subtract out scale factor of 1 passed to FLONUM-TO-STRING.
1487 (print-float-exponent x (1- ex) stream)))))
1489 ;;;; other leaf objects
1491 ;;; If *PRINT-ESCAPE* is false, just do a WRITE-CHAR, otherwise output
1492 ;;; the character name or the character in the #\char format.
1493 (defun output-character (char stream)
1494 (if (or *print-escape* *print-readably*)
1495 (let ((name (char-name char)))
1496 (write-string "#\\" stream)
1498 (quote-string name stream)
1499 (write-char char stream)))
1500 (write-char char stream)))
1502 (defun output-sap (sap stream)
1503 (declare (type system-area-pointer sap))
1505 (format stream "#.(~S #X~8,'0X)" 'int-sap (sap-int sap)))
1507 (print-unreadable-object (sap stream)
1508 (format stream "system area pointer: #X~8,'0X" (sap-int sap))))))
1510 (defun output-weak-pointer (weak-pointer stream)
1511 (declare (type weak-pointer weak-pointer))
1512 (print-unreadable-object (weak-pointer stream)
1513 (multiple-value-bind (value validp) (weak-pointer-value weak-pointer)
1515 (write-string "weak pointer: " stream)
1516 (write value :stream stream))
1518 (write-string "broken weak pointer" stream))))))
1520 (defun output-code-component (component stream)
1521 (print-unreadable-object (component stream :identity t)
1522 (let ((dinfo (%code-debug-info component)))
1523 (cond ((eq dinfo :bogus-lra)
1524 (write-string "bogus code object" stream))
1526 (write-string "code object" stream)
1528 (write-char #\space stream)
1529 (output-object (sb!c::debug-info-name dinfo) stream)))))))
1531 (defun output-lra (lra stream)
1532 (print-unreadable-object (lra stream :identity t)
1533 (write-string "return PC object" stream)))
1535 (defun output-fdefn (fdefn stream)
1536 (print-unreadable-object (fdefn stream)
1537 (write-string "FDEFINITION object for " stream)
1538 (output-object (fdefn-name fdefn) stream)))
1542 ;;; Output OBJECT as using PRINT-OBJECT if it's a
1543 ;;; FUNCALLABLE-STANDARD-CLASS, or return NIL otherwise.
1545 ;;; The definition here is a simple temporary placeholder. It will be
1546 ;;; overwritten by a smarter version (capable of calling generic
1547 ;;; PRINT-OBJECT when appropriate) when CLOS is installed.
1548 (defun printed-as-clos-funcallable-standard-class (object stream)
1549 (declare (ignore object stream))
1552 (defun output-function (object stream)
1553 (let* ((*print-length* 3) ; in case we have to..
1554 (*print-level* 3) ; ..print an interpreted function definition
1555 (name (cond ((find (function-subtype object)
1556 #(#.sb!vm:closure-header-type
1557 #.sb!vm:byte-code-closure-type))
1559 ((find (function-subtype object)
1560 #(#.sb!vm:function-header-type
1561 #.sb!vm:closure-function-header-type))
1562 (%function-name object))
1563 (t 'no-name-available)))
1564 (identified-by-name-p (and (symbolp name)
1566 (eq (fdefinition name) object))))
1567 (print-unreadable-object (object
1569 :identity (not identified-by-name-p))
1570 (prin1 'function stream)
1571 (unless (eq name 'no-name-available)
1572 (format stream " ~S" name)))))
1574 ;;;; catch-all for unknown things
1576 (defun output-random (object stream)
1577 (print-unreadable-object (object stream :identity t)
1578 (let ((lowtag (get-lowtag object)))
1580 (#.sb!vm:other-pointer-type
1581 (let ((type (get-type object)))
1583 (#.sb!vm:value-cell-header-type
1584 (write-string "value cell " stream)
1585 (output-object (sb!c:value-cell-ref object) stream))
1587 (write-string "unknown pointer object, type=" stream)
1588 (let ((*print-base* 16) (*print-radix* t))
1589 (output-integer type stream))))))
1590 ((#.sb!vm:function-pointer-type
1591 #.sb!vm:instance-pointer-type
1592 #.sb!vm:list-pointer-type)
1593 (write-string "unknown pointer object, type=" stream))
1595 (case (get-type object)
1596 (#.sb!vm:unbound-marker-type
1597 (write-string "unbound marker" stream))
1599 (write-string "unknown immediate object, lowtag=" stream)
1600 (let ((*print-base* 2) (*print-radix* t))
1601 (output-integer lowtag stream))
1602 (write-string ", type=" stream)
1603 (let ((*print-base* 16) (*print-radix* t))
1604 (output-integer (get-type object) stream)))))))))