;;;; the printer ;;;; This software is part of the SBCL system. See the README file for ;;;; more information. ;;;; ;;;; This software is derived from the CMU CL system, which was ;;;; written at Carnegie Mellon University and released into the ;;;; public domain. The software is in the public domain and is ;;;; provided with absolutely no warranty. See the COPYING and CREDITS ;;;; files for more information. (in-package "SB!IMPL") ;;;; exported printer control variables ;;; FIXME: Many of these have nontrivial types, e.g. *PRINT-LEVEL*, ;;; *PRINT-LENGTH*, and *PRINT-LINES* are (OR NULL UNSIGNED-BYTE). (defvar *print-readably* nil #!+sb-doc "If true, all objects will printed readably. If readable printing is impossible, an error will be signalled. This overrides the value of *PRINT-ESCAPE*.") (defvar *print-escape* T #!+sb-doc "Should we print in a reasonably machine-readable way? (possibly overridden by *PRINT-READABLY*)") (defvar *print-pretty* nil ; (set later when pretty-printer is initialized) #!+sb-doc "Should pretty printing be used?") (defvar *print-base* 10. #!+sb-doc "the output base for RATIONALs (including integers)") (defvar *print-radix* nil #!+sb-doc "Should base be verified when printing RATIONALs?") (defvar *print-level* nil #!+sb-doc "How many levels should be printed before abbreviating with \"#\"?") (defvar *print-length* nil #!+sb-doc "How many elements at any level should be printed before abbreviating with \"...\"?") (defvar *print-circle* nil #!+sb-doc "Should we use #n= and #n# notation to preserve uniqueness in general (and circularity in particular) when printing?") (defvar *print-case* :upcase #!+sb-doc "What case should the printer should use default?") (defvar *print-array* t #!+sb-doc "Should the contents of arrays be printed?") (defvar *print-gensym* t #!+sb-doc "Should #: prefixes be used when printing symbols with null SYMBOL-PACKAGE?") (defvar *print-lines* nil #!+sb-doc "the maximum number of lines to print per object") (defvar *print-right-margin* nil #!+sb-doc "the position of the right margin in ems (for pretty-printing)") (defvar *print-miser-width* nil #!+sb-doc "If the remaining space between the current column and the right margin is less than this, then print using ``miser-style'' output. Miser style conditional newlines are turned on, and all indentations are turned off. If NIL, never use miser mode.") (defvar *print-pprint-dispatch* nil #!+sb-doc "the pprint-dispatch-table that controls how to pretty-print objects") (defmacro with-standard-io-syntax (&body body) #!+sb-doc "Bind the reader and printer control variables to values that enable READ to reliably read the results of PRINT. These values are: *PACKAGE* the COMMON-LISP-USER package *PRINT-ARRAY* T *PRINT-BASE* 10 *PRINT-CASE* :UPCASE *PRINT-CIRCLE* NIL *PRINT-ESCAPE* T *PRINT-GENSYM* T *PRINT-LENGTH* NIL *PRINT-LEVEL* NIL *PRINT-LINES* NIL *PRINT-MISER-WIDTH* NIL *PRINT-PRETTY* NIL *PRINT-RADIX* NIL *PRINT-READABLY* T *PRINT-RIGHT-MARGIN* NIL *READ-BASE* 10 *READ-DEFAULT-FLOAT-FORMAT* SINGLE-FLOAT *READ-EVAL* T *READ-SUPPRESS* NIL *READTABLE* the standard readtable" `(%with-standard-io-syntax (lambda () ,@body))) (defun %with-standard-io-syntax (function) (declare (type function function)) (let ((*package* (find-package "COMMON-LISP-USER")) (*print-array* t) (*print-base* 10) (*print-case* :upcase) (*print-circle* nil) (*print-escape* t) (*print-gensym* t) (*print-length* nil) (*print-level* nil) (*print-lines* nil) (*print-miser-width* nil) (*print-pretty* nil) (*print-radix* nil) (*print-readably* t) (*print-right-margin* nil) (*read-base* 10) (*read-default-float-format* 'single-float) (*read-eval* t) (*read-suppress* nil) ;; FIXME: It doesn't seem like a good idea to expose our ;; disaster-recovery *STANDARD-READTABLE* here. What if some ;; enterprising user corrupts the disaster-recovery readtable ;; by doing destructive readtable operations within ;; WITH-STANDARD-IO-SYNTAX? Perhaps we should do a ;; COPY-READTABLE? The consing would be unfortunate, though. (*readtable* *standard-readtable*)) (funcall function))) ;;;; routines to print objects (defun write (object &key ((:stream stream) *standard-output*) ((:escape *print-escape*) *print-escape*) ((:radix *print-radix*) *print-radix*) ((:base *print-base*) *print-base*) ((:circle *print-circle*) *print-circle*) ((:pretty *print-pretty*) *print-pretty*) ((:level *print-level*) *print-level*) ((:length *print-length*) *print-length*) ((:case *print-case*) *print-case*) ((:array *print-array*) *print-array*) ((:gensym *print-gensym*) *print-gensym*) ((:readably *print-readably*) *print-readably*) ((:right-margin *print-right-margin*) *print-right-margin*) ((:miser-width *print-miser-width*) *print-miser-width*) ((:lines *print-lines*) *print-lines*) ((:pprint-dispatch *print-pprint-dispatch*) *print-pprint-dispatch*)) #!+sb-doc "Output OBJECT to the specified stream, defaulting to *STANDARD-OUTPUT*" (output-object object (out-synonym-of stream)) object) (defun prin1 (object &optional stream) #!+sb-doc "Output a mostly READable printed representation of OBJECT on the specified STREAM." (let ((*print-escape* T)) (output-object object (out-synonym-of stream))) object) (defun princ (object &optional stream) #!+sb-doc "Output an aesthetic but not necessarily READable printed representation of OBJECT on the specified STREAM." (let ((*print-escape* NIL) (*print-readably* NIL)) (output-object object (out-synonym-of stream))) object) (defun print (object &optional stream) #!+sb-doc "Output a newline, the mostly READable printed representation of OBJECT, and space to the specified STREAM." (let ((stream (out-synonym-of stream))) (terpri stream) (prin1 object stream) (write-char #\space stream) object)) (defun pprint (object &optional stream) #!+sb-doc "Prettily output OBJECT preceded by a newline." (let ((*print-pretty* t) (*print-escape* t) (stream (out-synonym-of stream))) (terpri stream) (output-object object stream)) (values)) (defun write-to-string (object &key ((:escape *print-escape*) *print-escape*) ((:radix *print-radix*) *print-radix*) ((:base *print-base*) *print-base*) ((:circle *print-circle*) *print-circle*) ((:pretty *print-pretty*) *print-pretty*) ((:level *print-level*) *print-level*) ((:length *print-length*) *print-length*) ((:case *print-case*) *print-case*) ((:array *print-array*) *print-array*) ((:gensym *print-gensym*) *print-gensym*) ((:readably *print-readably*) *print-readably*) ((:right-margin *print-right-margin*) *print-right-margin*) ((:miser-width *print-miser-width*) *print-miser-width*) ((:lines *print-lines*) *print-lines*) ((:pprint-dispatch *print-pprint-dispatch*) *print-pprint-dispatch*)) #!+sb-doc "Return the printed representation of OBJECT as a string." (stringify-object object)) (defun prin1-to-string (object) #!+sb-doc "Return the printed representation of OBJECT as a string with slashification on." (stringify-object object t)) (defun princ-to-string (object) #!+sb-doc "Return the printed representation of OBJECT as a string with slashification off." (stringify-object object nil)) ;;; This produces the printed representation of an object as a string. ;;; The few ...-TO-STRING functions above call this. (defvar *string-output-streams* ()) (defun stringify-object (object &optional (*print-escape* *print-escape*)) (let ((stream (if *string-output-streams* (pop *string-output-streams*) (make-string-output-stream)))) (setup-printer-state) (output-object object stream) (prog1 (get-output-stream-string stream) (push stream *string-output-streams*)))) ;;;; support for the PRINT-UNREADABLE-OBJECT macro ;;; guts of PRINT-UNREADABLE-OBJECT (defun %print-unreadable-object (object stream type identity body) (declare (type (or null function) body)) (when *print-readably* (error 'print-not-readable :object object)) (flet ((print-description () (when type (write (type-of object) :stream stream :circle nil :level nil :length nil) (when (or body identity) (write-char #\space stream) (pprint-newline :fill stream))) (when body (funcall body)) (when identity (when body (write-char #\space stream) (pprint-newline :fill stream)) (write-char #\{ stream) (write (get-lisp-obj-address object) :stream stream :radix nil :base 16) (write-char #\} stream)))) (cond ((print-pretty-on-stream-p stream) ;; Since we're printing prettily on STREAM, format the ;; object within a logical block. PPRINT-LOGICAL-BLOCK does ;; not rebind the stream when it is already a pretty stream, ;; so output from the body will go to the same stream. (pprint-logical-block (stream nil :prefix "#<" :suffix ">") (print-description))) (t (write-string "#<" stream) (print-description) (write-char #\> stream)))) nil) ;;;; circularity detection stuff ;;; When *PRINT-CIRCLE* is T, this gets bound to a hash table that ;;; (eventually) ends up with entries for every object printed. When ;;; we are initially looking for circularities, we enter a T when we ;;; find an object for the first time, and a 0 when we encounter an ;;; object a second time around. When we are actually printing, the 0 ;;; entries get changed to the actual marker value when they are first ;;; printed. (defvar *circularity-hash-table* nil) ;;; When NIL, we are just looking for circularities. After we have ;;; found them all, this gets bound to 0. Then whenever we need a new ;;; marker, it is incremented. (defvar *circularity-counter* nil) ;;; Check to see whether OBJECT is a circular reference, and return ;;; something non-NIL if it is. If ASSIGN is T, then the number to use ;;; in the #n= and #n# noise is assigned at this time. ;;; If ASSIGN is true, reference bookkeeping will only be done for ;;; existing entries, no new references will be recorded! ;;; ;;; Note: CHECK-FOR-CIRCULARITY must be called *exactly* once with ;;; ASSIGN true, or the circularity detection noise will get confused ;;; about when to use #n= and when to use #n#. If this returns non-NIL ;;; when ASSIGN is true, then you must call HANDLE-CIRCULARITY on it. ;;; If CHECK-FOR-CIRCULARITY returns :INITIATE as the second value, ;;; you need to initiate the circularity detection noise, e.g. bind ;;; *CIRCULARITY-HASH-TABLE* and *CIRCULARITY-COUNTER* to suitable values ;;; (see #'OUTPUT-OBJECT for an example). (defun check-for-circularity (object &optional assign) (cond ((null *print-circle*) ;; Don't bother, nobody cares. nil) ((null *circularity-hash-table*) (values nil :initiate)) ((null *circularity-counter*) (ecase (gethash object *circularity-hash-table*) ((nil) ;; first encounter (setf (gethash object *circularity-hash-table*) t) ;; We need to keep looking. nil) ((t) ;; second encounter (setf (gethash object *circularity-hash-table*) 0) ;; It's a circular reference. t) (0 ;; It's a circular reference. t))) (t (let ((value (gethash object *circularity-hash-table*))) (case value ((nil t) ;; If NIL, we found an object that wasn't there the ;; first time around. If T, this object appears exactly ;; once. Either way, just print the thing without any ;; special processing. Note: you might argue that ;; finding a new object means that something is broken, ;; but this can happen. If someone uses the ~@<...~:> ;; format directive, it conses a new list each time ;; though format (i.e. the &REST list), so we will have ;; different cdrs. nil) (0 (if assign (let ((value (incf *circularity-counter*))) ;; first occurrence of this object: Set the counter. (setf (gethash object *circularity-hash-table*) value) value) t)) (t ;; second or later occurrence (- value))))))) ;;; Handle the results of CHECK-FOR-CIRCULARITY. If this returns T then ;;; you should go ahead and print the object. If it returns NIL, then ;;; you should blow it off. (defun handle-circularity (marker stream) (case marker (:initiate ;; Someone forgot to initiate circularity detection. (let ((*print-circle* nil)) (error "trying to use CHECK-FOR-CIRCULARITY when ~ circularity checking isn't initiated"))) ((t) ;; It's a second (or later) reference to the object while we are ;; just looking. So don't bother groveling it again. nil) (t (write-char #\# stream) (let ((*print-base* 10) (*print-radix* nil)) (cond ((minusp marker) (output-integer (- marker) stream) (write-char #\# stream) nil) (t (output-integer marker stream) (write-char #\= stream) t)))))) ;;;; OUTPUT-OBJECT -- the main entry point ;;; Objects whose print representation identifies them EQLly don't ;;; need to be checked for circularity. (defun uniquely-identified-by-print-p (x) (or (numberp x) (characterp x) (and (symbolp x) (symbol-package x)))) ;;; Output OBJECT to STREAM observing all printer control variables. (defun output-object (object stream) (labels ((print-it (stream) (if *print-pretty* (sb!pretty:output-pretty-object object stream) (output-ugly-object object stream))) (check-it (stream) (multiple-value-bind (marker initiate) (check-for-circularity object t) ;; initialization of the circulation detect noise ... (if (eq initiate :initiate) (let ((*circularity-hash-table* (make-hash-table :test 'eq))) (check-it (make-broadcast-stream)) (let ((*circularity-counter* 0)) (check-it stream))) ;; otherwise (if marker (when (handle-circularity marker stream) (print-it stream)) (print-it stream)))))) (cond (;; Maybe we don't need to bother with circularity detection. (or (not *print-circle*) (uniquely-identified-by-print-p object)) (print-it stream)) (;; If we have already started circularity detection, this ;; object might be a shared reference. If we have not, then ;; if it is a compound object it might contain a circular ;; reference to itself or multiple shared references. (or *circularity-hash-table* (compound-object-p object)) (check-it stream)) (t (print-it stream))))) ;;; a hack to work around recurring gotchas with printing while ;;; DEFGENERIC PRINT-OBJECT is being built ;;; ;;; (hopefully will go away naturally when CLOS moves into cold init) (defvar *print-object-is-disabled-p*) ;;; Output OBJECT to STREAM observing all printer control variables ;;; except for *PRINT-PRETTY*. Note: if *PRINT-PRETTY* is non-NIL, ;;; then the pretty printer will be used for any components of OBJECT, ;;; just not for OBJECT itself. (defun output-ugly-object (object stream) (typecase object ;; KLUDGE: The TYPECASE approach here is non-ANSI; the ANSI definition of ;; PRINT-OBJECT says it provides printing and we're supposed to provide ;; PRINT-OBJECT methods covering all classes. We deviate from this ;; by using PRINT-OBJECT only when we print instance values. However, ;; ANSI makes it hard to tell that we're deviating from this: ;; (1) ANSI specifies that the user isn't supposed to call PRINT-OBJECT ;; directly. ;; (2) ANSI (section 11.1.2.1.2) says it's undefined to define ;; a method on an external symbol in the CL package which is ;; applicable to arg lists containing only direct instances of ;; standardized classes. ;; Thus, in order for the user to detect our sleaziness in conforming ;; code, he has to do something relatively obscure like ;; (1) actually use tools like FIND-METHOD to look for PRINT-OBJECT ;; methods, or ;; (2) define a PRINT-OBJECT method which is specialized on the stream ;; value (e.g. a Gray stream object). ;; As long as no one comes up with a non-obscure way of detecting this ;; sleaziness, fixing this nonconformity will probably have a low ;; priority. -- WHN 2001-11-25 (fixnum (output-integer object stream)) (list (if (null object) (output-symbol object stream) (output-list object stream))) (instance (cond ((not (and (boundp '*print-object-is-disabled-p*) *print-object-is-disabled-p*)) (print-object object stream)) ((typep object 'structure-object) (default-structure-print object stream *current-level-in-print*)) (t (write-string "#" stream)))) (function (unless (and (funcallable-instance-p object) (printed-as-funcallable-standard-class object stream)) (output-fun object stream))) (symbol (output-symbol object stream)) (number (etypecase object (integer (output-integer object stream)) (float (output-float object stream)) (ratio (output-ratio object stream)) (ratio (output-ratio object stream)) (complex (output-complex object stream)))) (character (output-character object stream)) (vector (output-vector object stream)) (array (output-array object stream)) (system-area-pointer (output-sap object stream)) (weak-pointer (output-weak-pointer object stream)) (lra (output-lra object stream)) (code-component (output-code-component object stream)) (fdefn (output-fdefn object stream)) (t (output-random object stream)))) ;;;; symbols ;;; values of *PRINT-CASE* and (READTABLE-CASE *READTABLE*) the last ;;; time the printer was called (defvar *previous-case* nil) (defvar *previous-readtable-case* nil) ;;; This variable contains the current definition of one of three ;;; symbol printers. SETUP-PRINTER-STATE sets this variable. (defvar *internal-symbol-output-fun* nil) ;;; This function sets the internal global symbol ;;; *INTERNAL-SYMBOL-OUTPUT-FUN* to the right function depending on ;;; the value of *PRINT-CASE*. See the manual for details. The print ;;; buffer stream is also reset. (defun setup-printer-state () (unless (and (eq *print-case* *previous-case*) (eq (readtable-case *readtable*) *previous-readtable-case*)) (setq *previous-case* *print-case*) (setq *previous-readtable-case* (readtable-case *readtable*)) (unless (member *print-case* '(:upcase :downcase :capitalize)) (setq *print-case* :upcase) (error "invalid *PRINT-CASE* value: ~S" *previous-case*)) (unless (member *previous-readtable-case* '(:upcase :downcase :invert :preserve)) (setf (readtable-case *readtable*) :upcase) (error "invalid READTABLE-CASE value: ~S" *previous-readtable-case*)) (setq *internal-symbol-output-fun* (case *previous-readtable-case* (:upcase (case *print-case* (:upcase #'output-preserve-symbol) (:downcase #'output-lowercase-symbol) (:capitalize #'output-capitalize-symbol))) (:downcase (case *print-case* (:upcase #'output-uppercase-symbol) (:downcase #'output-preserve-symbol) (:capitalize #'output-capitalize-symbol))) (:preserve #'output-preserve-symbol) (:invert #'output-invert-symbol))))) ;;; Output PNAME (a symbol-name or package-name) surrounded with |'s, ;;; and with any embedded |'s or \'s escaped. (defun output-quoted-symbol-name (pname stream) (write-char #\| stream) (dotimes (index (length pname)) (let ((char (schar pname index))) (when (or (char= char #\\) (char= char #\|)) (write-char #\\ stream)) (write-char char stream))) (write-char #\| stream)) (defun output-symbol (object stream) (if (or *print-escape* *print-readably*) (let ((package (symbol-package object)) (name (symbol-name object))) (cond ;; The ANSI spec "22.1.3.3.1 Package Prefixes for Symbols" ;; requires that keywords be printed with preceding colons ;; always, regardless of the value of *PACKAGE*. ((eq package *keyword-package*) (write-char #\: stream)) ;; Otherwise, if the symbol's home package is the current ;; one, then a prefix is never necessary. ((eq package (sane-package))) ;; Uninterned symbols print with a leading #:. ((null package) (when (or *print-gensym* *print-readably*) (write-string "#:" stream))) (t (multiple-value-bind (symbol accessible) (find-symbol name (sane-package)) ;; If we can find the symbol by looking it up, it need not ;; be qualified. This can happen if the symbol has been ;; inherited from a package other than its home package. (unless (and accessible (eq symbol object)) (output-symbol-name (package-name package) stream) (multiple-value-bind (symbol externalp) (find-external-symbol name package) (declare (ignore symbol)) (if externalp (write-char #\: stream) (write-string "::" stream))))))) (output-symbol-name name stream)) (output-symbol-name (symbol-name object) stream nil))) ;;; Output the string NAME as if it were a symbol name. In other ;;; words, diddle its case according to *PRINT-CASE* and ;;; READTABLE-CASE. (defun output-symbol-name (name stream &optional (maybe-quote t)) (declare (type simple-base-string name)) (setup-printer-state) (if (and maybe-quote (symbol-quotep name)) (output-quoted-symbol-name name stream) (funcall *internal-symbol-output-fun* name stream))) ;;;; escaping symbols ;;; When we print symbols we have to figure out if they need to be ;;; printed with escape characters. This isn't a whole lot easier than ;;; reading symbols in the first place. ;;; ;;; For each character, the value of the corresponding element is a ;;; fixnum with bits set corresponding to attributes that the ;;; character has. At characters have at least one bit set, so we can ;;; search for any character with a positive test. (defvar *character-attributes* (make-array char-code-limit :element-type '(unsigned-byte 16) :initial-element 0)) (declaim (type (simple-array (unsigned-byte 16) (#.char-code-limit)) *character-attributes*)) ;;; constants which are a bit-mask for each interesting character attribute (defconstant other-attribute (ash 1 0)) ; Anything else legal. (defconstant number-attribute (ash 1 1)) ; A numeric digit. (defconstant uppercase-attribute (ash 1 2)) ; An uppercase letter. (defconstant lowercase-attribute (ash 1 3)) ; A lowercase letter. (defconstant sign-attribute (ash 1 4)) ; +- (defconstant extension-attribute (ash 1 5)) ; ^_ (defconstant dot-attribute (ash 1 6)) ; . (defconstant slash-attribute (ash 1 7)) ; / (defconstant funny-attribute (ash 1 8)) ; Anything illegal. (eval-when (:compile-toplevel :load-toplevel :execute) ;;; LETTER-ATTRIBUTE is a local of SYMBOL-QUOTEP. It matches letters ;;; that don't need to be escaped (according to READTABLE-CASE.) (defparameter *attribute-names* `((number . number-attribute) (lowercase . lowercase-attribute) (uppercase . uppercase-attribute) (letter . letter-attribute) (sign . sign-attribute) (extension . extension-attribute) (dot . dot-attribute) (slash . slash-attribute) (other . other-attribute) (funny . funny-attribute))) ) ; EVAL-WHEN (flet ((set-bit (char bit) (let ((code (char-code char))) (setf (aref *character-attributes* code) (logior bit (aref *character-attributes* code)))))) (dolist (char '(#\! #\@ #\$ #\% #\& #\* #\= #\~ #\[ #\] #\{ #\} #\? #\< #\>)) (set-bit char other-attribute)) (dotimes (i 10) (set-bit (digit-char i) number-attribute)) (do ((code (char-code #\A) (1+ code)) (end (char-code #\Z))) ((> code end)) (declare (fixnum code end)) (set-bit (code-char code) uppercase-attribute) (set-bit (char-downcase (code-char code)) lowercase-attribute)) (set-bit #\- sign-attribute) (set-bit #\+ sign-attribute) (set-bit #\^ extension-attribute) (set-bit #\_ extension-attribute) (set-bit #\. dot-attribute) (set-bit #\/ slash-attribute) ;; Mark anything not explicitly allowed as funny. (dotimes (i char-code-limit) (when (zerop (aref *character-attributes* i)) (setf (aref *character-attributes* i) funny-attribute)))) ;;; For each character, the value of the corresponding element is the ;;; lowest base in which that character is a digit. (defvar *digit-bases* (make-array char-code-limit :element-type '(unsigned-byte 8) :initial-element 36)) (declaim (type (simple-array (unsigned-byte 8) (#.char-code-limit)) *digit-bases*)) (dotimes (i 36) (let ((char (digit-char i 36))) (setf (aref *digit-bases* (char-code char)) i))) ;;; A FSM-like thingie that determines whether a symbol is a potential ;;; number or has evil characters in it. (defun symbol-quotep (name) (declare (simple-string name)) (macrolet ((advance (tag &optional (at-end t)) `(progn (when (= index len) ,(if at-end '(go TEST-SIGN) '(return nil))) (setq current (schar name index) code (char-code current) bits (aref attributes code)) (incf index) (go ,tag))) (test (&rest attributes) `(not (zerop (the fixnum (logand (logior ,@(mapcar (lambda (x) (or (cdr (assoc x *attribute-names*)) (error "Blast!"))) attributes)) bits))))) (digitp () `(< (the fixnum (aref bases code)) base))) (prog ((len (length name)) (attributes *character-attributes*) (bases *digit-bases*) (base *print-base*) (letter-attribute (case (readtable-case *readtable*) (:upcase uppercase-attribute) (:downcase lowercase-attribute) (t (logior lowercase-attribute uppercase-attribute)))) (index 0) (bits 0) (code 0) current) (declare (fixnum len base index bits code)) (advance START t) TEST-SIGN ; At end, see whether it is a sign... (return (not (test sign))) OTHER ; not potential number, see whether funny chars... (let ((mask (logxor (logior lowercase-attribute uppercase-attribute funny-attribute) letter-attribute))) (do ((i (1- index) (1+ i))) ((= i len) (return-from symbol-quotep nil)) (unless (zerop (logand (aref attributes (char-code (schar name i))) mask)) (return-from symbol-quotep t)))) START (when (digitp) (if (test letter) (advance LAST-DIGIT-ALPHA) (advance DIGIT))) (when (test letter number other slash) (advance OTHER nil)) (when (char= current #\.) (advance DOT-FOUND)) (when (test sign extension) (advance START-STUFF nil)) (return t) DOT-FOUND ; leading dots... (when (test letter) (advance START-DOT-MARKER nil)) (when (digitp) (advance DOT-DIGIT)) (when (test number other) (advance OTHER nil)) (when (test extension slash sign) (advance START-DOT-STUFF nil)) (when (char= current #\.) (advance DOT-FOUND)) (return t) START-STUFF ; leading stuff before any dot or digit (when (digitp) (if (test letter) (advance LAST-DIGIT-ALPHA) (advance DIGIT))) (when (test number other) (advance OTHER nil)) (when (test letter) (advance START-MARKER nil)) (when (char= current #\.) (advance START-DOT-STUFF nil)) (when (test sign extension slash) (advance START-STUFF nil)) (return t) START-MARKER ; number marker in leading stuff... (when (test letter) (advance OTHER nil)) (go START-STUFF) START-DOT-STUFF ; leading stuff containing dot without digit... (when (test letter) (advance START-DOT-STUFF nil)) (when (digitp) (advance DOT-DIGIT)) (when (test sign extension dot slash) (advance START-DOT-STUFF nil)) (when (test number other) (advance OTHER nil)) (return t) START-DOT-MARKER ; number marker in leading stuff with dot.. ;; leading stuff containing dot without digit followed by letter... (when (test letter) (advance OTHER nil)) (go START-DOT-STUFF) DOT-DIGIT ; in a thing with dots... (when (test letter) (advance DOT-MARKER)) (when (digitp) (advance DOT-DIGIT)) (when (test number other) (advance OTHER nil)) (when (test sign extension dot slash) (advance DOT-DIGIT)) (return t) DOT-MARKER ; number marker in number with dot... (when (test letter) (advance OTHER nil)) (go DOT-DIGIT) LAST-DIGIT-ALPHA ; previous char is a letter digit... (when (or (digitp) (test sign slash)) (advance ALPHA-DIGIT)) (when (test letter number other dot) (advance OTHER nil)) (return t) ALPHA-DIGIT ; seen a digit which is a letter... (when (or (digitp) (test sign slash)) (if (test letter) (advance LAST-DIGIT-ALPHA) (advance ALPHA-DIGIT))) (when (test letter) (advance ALPHA-MARKER)) (when (test number other dot) (advance OTHER nil)) (return t) ALPHA-MARKER ; number marker in number with alpha digit... (when (test letter) (advance OTHER nil)) (go ALPHA-DIGIT) DIGIT ; seen only ordinary (non-alphabetic) numeric digits... (when (digitp) (if (test letter) (advance ALPHA-DIGIT) (advance DIGIT))) (when (test number other) (advance OTHER nil)) (when (test letter) (advance MARKER)) (when (test extension slash sign) (advance DIGIT)) (when (char= current #\.) (advance DOT-DIGIT)) (return t) MARKER ; number marker in a numeric number... (when (test letter) (advance OTHER nil)) (go DIGIT)))) ;;;; *INTERNAL-SYMBOL-OUTPUT-FUN* ;;;; ;;;; case hackery: These functions are stored in ;;;; *INTERNAL-SYMBOL-OUTPUT-FUN* according to the values of ;;;; *PRINT-CASE* and READTABLE-CASE. ;;; called when: ;;; READTABLE-CASE *PRINT-CASE* ;;; :UPCASE :UPCASE ;;; :DOWNCASE :DOWNCASE ;;; :PRESERVE any (defun output-preserve-symbol (pname stream) (declare (simple-string pname)) (write-string pname stream)) ;;; called when: ;;; READTABLE-CASE *PRINT-CASE* ;;; :UPCASE :DOWNCASE (defun output-lowercase-symbol (pname stream) (declare (simple-string pname)) (dotimes (index (length pname)) (let ((char (schar pname index))) (write-char (char-downcase char) stream)))) ;;; called when: ;;; READTABLE-CASE *PRINT-CASE* ;;; :DOWNCASE :UPCASE (defun output-uppercase-symbol (pname stream) (declare (simple-string pname)) (dotimes (index (length pname)) (let ((char (schar pname index))) (write-char (char-upcase char) stream)))) ;;; called when: ;;; READTABLE-CASE *PRINT-CASE* ;;; :UPCASE :CAPITALIZE ;;; :DOWNCASE :CAPITALIZE (defun output-capitalize-symbol (pname stream) (declare (simple-string pname)) (let ((prev-not-alpha t) (up (eq (readtable-case *readtable*) :upcase))) (dotimes (i (length pname)) (let ((char (char pname i))) (write-char (if up (if (or prev-not-alpha (lower-case-p char)) char (char-downcase char)) (if prev-not-alpha (char-upcase char) char)) stream) (setq prev-not-alpha (not (alpha-char-p char))))))) ;;; called when: ;;; READTABLE-CASE *PRINT-CASE* ;;; :INVERT any (defun output-invert-symbol (pname stream) (declare (simple-string pname)) (let ((all-upper t) (all-lower t)) (dotimes (i (length pname)) (let ((ch (schar pname i))) (when (both-case-p ch) (if (upper-case-p ch) (setq all-lower nil) (setq all-upper nil))))) (cond (all-upper (output-lowercase-symbol pname stream)) (all-lower (output-uppercase-symbol pname stream)) (t (write-string pname stream))))) #| (defun test1 () (let ((*readtable* (copy-readtable nil))) (format t "READTABLE-CASE Input Symbol-name~@ ----------------------------------~%") (dolist (readtable-case '(:upcase :downcase :preserve :invert)) (setf (readtable-case *readtable*) readtable-case) (dolist (input '("ZEBRA" "Zebra" "zebra")) (format t "~&:~A~16T~A~24T~A" (string-upcase readtable-case) input (symbol-name (read-from-string input))))))) (defun test2 () (let ((*readtable* (copy-readtable nil))) (format t "READTABLE-CASE *PRINT-CASE* Symbol-name Output Princ~@ --------------------------------------------------------~%") (dolist (readtable-case '(:upcase :downcase :preserve :invert)) (setf (readtable-case *readtable*) readtable-case) (dolist (*print-case* '(:upcase :downcase :capitalize)) (dolist (symbol '(|ZEBRA| |Zebra| |zebra|)) (format t "~&:~A~15T:~A~29T~A~42T~A~50T~A" (string-upcase readtable-case) (string-upcase *print-case*) (symbol-name symbol) (prin1-to-string symbol) (princ-to-string symbol))))))) |# ;;;; recursive objects (defun output-list (list stream) (descend-into (stream) (write-char #\( stream) (let ((length 0) (list list)) (loop (punt-print-if-too-long length stream) (output-object (pop list) stream) (unless list (return)) (when (or (atom list) (check-for-circularity list)) (write-string " . " stream) (output-object list stream) (return)) (write-char #\space stream) (incf length))) (write-char #\) stream))) (defun output-vector (vector stream) (declare (vector vector)) (cond ((stringp vector) (cond ((or *print-escape* *print-readably*) (write-char #\" stream) (quote-string vector stream) (write-char #\" stream)) (t (write-string vector stream)))) ((not (or *print-array* *print-readably*)) (output-terse-array vector stream)) ((bit-vector-p vector) (write-string "#*" stream) (dovector (bit vector) ;; (Don't use OUTPUT-OBJECT here, since this code ;; has to work for all possible *PRINT-BASE* values.) (write-char (if (zerop bit) #\0 #\1) stream))) (t (when (and *print-readably* (not (array-readably-printable-p array))) (error 'print-not-readable :object vector)) (descend-into (stream) (write-string "#(" stream) (dotimes (i (length vector)) (unless (zerop i) (write-char #\space stream)) (punt-print-if-too-long i stream) (output-object (aref vector i) stream)) (write-string ")" stream))))) ;;; This function outputs a string quoting characters sufficiently ;;; so that someone can read it in again. Basically, put a slash in ;;; front of an character satisfying NEEDS-SLASH-P. (defun quote-string (string stream) (macrolet ((needs-slash-p (char) ;; KLUDGE: We probably should look at the readtable, but just do ;; this for now. [noted by anonymous long ago] -- WHN 19991130 `(or (char= ,char #\\) (char= ,char #\")))) (with-array-data ((data string) (start) (end (length string))) (do ((index start (1+ index))) ((>= index end)) (let ((char (schar data index))) (when (needs-slash-p char) (write-char #\\ stream)) (write-char char stream)))))) (defun array-readably-printable-p (array) (and (eq (array-element-type array) t) (let ((zero (position 0 (array-dimensions array))) (number (position 0 (array-dimensions array) :test (complement #'eql) :from-end t))) (or (null zero) (null number) (> zero number))))) ;;; Output the printed representation of any array in either the #< or #A ;;; form. (defun output-array (array stream) (if (or *print-array* *print-readably*) (output-array-guts array stream) (output-terse-array array stream))) ;;; Output the abbreviated #< form of an array. (defun output-terse-array (array stream) (let ((*print-level* nil) (*print-length* nil)) (print-unreadable-object (array stream :type t :identity t)))) ;;; Output the readable #A form of an array. (defun output-array-guts (array stream) (when (and *print-readably* (not (array-readably-printable-p array))) (error 'print-not-readable :object array)) (write-char #\# stream) (let ((*print-base* 10)) (output-integer (array-rank array) stream)) (write-char #\A stream) (with-array-data ((data array) (start) (end)) (declare (ignore end)) (sub-output-array-guts data (array-dimensions array) stream start))) (defun sub-output-array-guts (array dimensions stream index) (declare (type (simple-array * (*)) array) (fixnum index)) (cond ((null dimensions) (output-object (aref array index) stream)) (t (descend-into (stream) (write-char #\( stream) (let* ((dimension (car dimensions)) (dimensions (cdr dimensions)) (count (reduce #'* dimensions))) (dotimes (i dimension) (unless (zerop i) (write-char #\space stream)) (punt-print-if-too-long i stream) (sub-output-array-guts array dimensions stream index) (incf index count))) (write-char #\) stream))))) ;;; a trivial non-generic-function placeholder for PRINT-OBJECT, for ;;; use until CLOS is set up (at which time it will be replaced with ;;; the real generic function implementation) (defun print-object (instance stream) (default-structure-print instance stream *current-level-in-print*)) ;;;; integer, ratio, and complex printing (i.e. everything but floats) (defun output-integer (integer stream) ;; FIXME: This UNLESS form should be pulled out into something like ;; (SANE-PRINT-BASE), along the lines of (SANE-PACKAGE) for the ;; *PACKAGE* variable. (unless (and (fixnump *print-base*) (< 1 *print-base* 37)) (let ((obase *print-base*)) (setq *print-base* 10.) (error "~A is not a reasonable value for *PRINT-BASE*." obase))) (when (and (not (= *print-base* 10.)) *print-radix*) ;; First print leading base information, if any. (write-char #\# stream) (write-char (case *print-base* (2. #\b) (8. #\o) (16. #\x) (T (let ((fixbase *print-base*) (*print-base* 10.) (*print-radix* ())) (sub-output-integer fixbase stream)) #\r)) stream)) ;; Then output a minus sign if the number is negative, then output ;; the absolute value of the number. (cond ((bignump integer) (print-bignum integer stream)) ((< integer 0) (write-char #\- stream) (sub-output-integer (- integer) stream)) (t (sub-output-integer integer stream))) ;; Print any trailing base information, if any. (if (and (= *print-base* 10.) *print-radix*) (write-char #\. stream))) (defun sub-output-integer (integer stream) (let ((quotient ()) (remainder ())) ;; Recurse until you have all the digits pushed on the stack. (if (not (zerop (multiple-value-setq (quotient remainder) (truncate integer *print-base*)))) (sub-output-integer quotient stream)) ;; Then as each recursive call unwinds, turn the digit (in remainder) ;; into a character and output the character. (write-char (code-char (if (and (> remainder 9.) (> *print-base* 10.)) (+ (char-code #\A) (- remainder 10.)) (+ (char-code #\0) remainder))) stream))) ;;;; bignum printing ;;; *BASE-POWER* holds the number that we keep dividing into the ;;; bignum for each *print-base*. We want this number as close to ;;; *most-positive-fixnum* as possible, i.e. (floor (log ;;; most-positive-fixnum *print-base*)). (defparameter *base-power* (make-array 37 :initial-element nil)) ;;; *FIXNUM-POWER--1* holds the number of digits for each *PRINT-BASE* ;;; that fit in the corresponding *base-power*. (defparameter *fixnum-power--1* (make-array 37 :initial-element nil)) ;;; Print the bignum to the stream. We first generate the correct ;;; value for *base-power* and *fixnum-power--1* if we have not ;;; already. Then we call bignum-print-aux to do the printing. (defun print-bignum (big stream) (unless (aref *base-power* *print-base*) (do ((power-1 -1 (1+ power-1)) (new-divisor *print-base* (* new-divisor *print-base*)) (divisor 1 new-divisor)) ((not (fixnump new-divisor)) (setf (aref *base-power* *print-base*) divisor) (setf (aref *fixnum-power--1* *print-base*) power-1)))) (bignum-print-aux (cond ((minusp big) (write-char #\- stream) (- big)) (t big)) (aref *base-power* *print-base*) (aref *fixnum-power--1* *print-base*) stream) big) (defun bignum-print-aux (big divisor power-1 stream) (multiple-value-bind (newbig fix) (truncate big divisor) (if (fixnump newbig) (sub-output-integer newbig stream) (bignum-print-aux newbig divisor power-1 stream)) (do ((zeros power-1 (1- zeros)) (base-power *print-base* (* base-power *print-base*))) ((> base-power fix) (dotimes (i zeros) (write-char #\0 stream)) (sub-output-integer fix stream))))) (defun output-ratio (ratio stream) (when *print-radix* (write-char #\# stream) (case *print-base* (2 (write-char #\b stream)) (8 (write-char #\o stream)) (16 (write-char #\x stream)) (t (write *print-base* :stream stream :radix nil :base 10))) (write-char #\r stream)) (let ((*print-radix* nil)) (output-integer (numerator ratio) stream) (write-char #\/ stream) (output-integer (denominator ratio) stream))) (defun output-complex (complex stream) (write-string "#C(" stream) (output-object (realpart complex) stream) (write-char #\space stream) (output-object (imagpart complex) stream) (write-char #\) stream)) ;;;; float printing ;;; FLONUM-TO-STRING (and its subsidiary function FLOAT-STRING) does ;;; most of the work for all printing of floating point numbers in the ;;; printer and in FORMAT. It converts a floating point number to a ;;; string in a free or fixed format with no exponent. The ;;; interpretation of the arguments is as follows: ;;; ;;; X - The floating point number to convert, which must not be ;;; negative. ;;; WIDTH - The preferred field width, used to determine the number ;;; of fraction digits to produce if the FDIGITS parameter ;;; is unspecified or NIL. If the non-fraction digits and the ;;; decimal point alone exceed this width, no fraction digits ;;; will be produced unless a non-NIL value of FDIGITS has been ;;; specified. Field overflow is not considerd an error at this ;;; level. ;;; FDIGITS - The number of fractional digits to produce. Insignificant ;;; trailing zeroes may be introduced as needed. May be ;;; unspecified or NIL, in which case as many digits as possible ;;; are generated, subject to the constraint that there are no ;;; trailing zeroes. ;;; SCALE - If this parameter is specified or non-NIL, then the number ;;; printed is (* x (expt 10 scale)). This scaling is exact, ;;; and cannot lose precision. ;;; FMIN - This parameter, if specified or non-NIL, is the minimum ;;; number of fraction digits which will be produced, regardless ;;; of the value of WIDTH or FDIGITS. This feature is used by ;;; the ~E format directive to prevent complete loss of ;;; significance in the printed value due to a bogus choice of ;;; scale factor. ;;; ;;; Most of the optional arguments are for the benefit for FORMAT and are not ;;; used by the printer. ;;; ;;; Returns: ;;; (VALUES DIGIT-STRING DIGIT-LENGTH LEADING-POINT TRAILING-POINT DECPNT) ;;; where the results have the following interpretation: ;;; ;;; DIGIT-STRING - The decimal representation of X, with decimal point. ;;; DIGIT-LENGTH - The length of the string DIGIT-STRING. ;;; LEADING-POINT - True if the first character of DIGIT-STRING is the ;;; decimal point. ;;; TRAILING-POINT - True if the last character of DIGIT-STRING is the ;;; decimal point. ;;; POINT-POS - The position of the digit preceding the decimal ;;; point. Zero indicates point before first digit. ;;; ;;; NOTE: FLONUM-TO-STRING goes to a lot of trouble to guarantee ;;; accuracy. Specifically, the decimal number printed is the closest ;;; possible approximation to the true value of the binary number to ;;; be printed from among all decimal representations with the same ;;; number of digits. In free-format output, i.e. with the number of ;;; digits unconstrained, it is guaranteed that all the information is ;;; preserved, so that a properly- rounding reader can reconstruct the ;;; original binary number, bit-for-bit, from its printed decimal ;;; representation. Furthermore, only as many digits as necessary to ;;; satisfy this condition will be printed. ;;; ;;; FLOAT-STRING actually generates the digits for positive numbers. ;;; The algorithm is essentially that of algorithm Dragon4 in "How to ;;; Print Floating-Point Numbers Accurately" by Steele and White. The ;;; current (draft) version of this paper may be found in ;;; [CMUC]tradix.press. DO NOT EVEN THINK OF ATTEMPTING TO ;;; UNDERSTAND THIS CODE WITHOUT READING THE PAPER! (defvar *digits* "0123456789") (defun flonum-to-string (x &optional width fdigits scale fmin) (cond ((zerop x) ;; Zero is a special case which FLOAT-STRING cannot handle. (if fdigits (let ((s (make-string (1+ fdigits) :initial-element #\0))) (setf (schar s 0) #\.) (values s (length s) t (zerop fdigits) 0)) (values "." 1 t t 0))) (t (multiple-value-bind (sig exp) (integer-decode-float x) (let* ((precision (float-precision x)) (digits (float-digits x)) (fudge (- digits precision)) (width (if width (max width 1) nil))) (float-string (ash sig (- fudge)) (+ exp fudge) precision width fdigits scale fmin)))))) (defun float-string (fraction exponent precision width fdigits scale fmin) (let ((r fraction) (s 1) (m- 1) (m+ 1) (k 0) (digits 0) (decpnt 0) (cutoff nil) (roundup nil) u low high (digit-string (make-array 50 :element-type 'base-char :fill-pointer 0 :adjustable t))) ;; Represent fraction as r/s, error bounds as m+/s and m-/s. ;; Rational arithmetic avoids loss of precision in subsequent ;; calculations. (cond ((> exponent 0) (setq r (ash fraction exponent)) (setq m- (ash 1 exponent)) (setq m+ m-)) ((< exponent 0) (setq s (ash 1 (- exponent))))) ;; Adjust the error bounds m+ and m- for unequal gaps. (when (= fraction (ash 1 precision)) (setq m+ (ash m+ 1)) (setq r (ash r 1)) (setq s (ash s 1))) ;; Scale value by requested amount, and update error bounds. (when scale (if (minusp scale) (let ((scale-factor (expt 10 (- scale)))) (setq s (* s scale-factor))) (let ((scale-factor (expt 10 scale))) (setq r (* r scale-factor)) (setq m+ (* m+ scale-factor)) (setq m- (* m- scale-factor))))) ;; Scale r and s and compute initial k, the base 10 logarithm of r. (do () ((>= r (ceiling s 10))) (decf k) (setq r (* r 10)) (setq m- (* m- 10)) (setq m+ (* m+ 10))) (do ()(nil) (do () ((< (+ (ash r 1) m+) (ash s 1))) (setq s (* s 10)) (incf k)) ;; Determine number of fraction digits to generate. (cond (fdigits ;; Use specified number of fraction digits. (setq cutoff (- fdigits)) ;;don't allow less than fmin fraction digits (if (and fmin (> cutoff (- fmin))) (setq cutoff (- fmin)))) (width ;; Use as many fraction digits as width will permit but ;; force at least fmin digits even if width will be ;; exceeded. (if (< k 0) (setq cutoff (- 1 width)) (setq cutoff (1+ (- k width)))) (if (and fmin (> cutoff (- fmin))) (setq cutoff (- fmin))))) ;; If we decided to cut off digit generation before precision ;; has been exhausted, rounding the last digit may cause a carry ;; propagation. We can prevent this, preserving left-to-right ;; digit generation, with a few magical adjustments to m- and ;; m+. Of course, correct rounding is also preserved. (when (or fdigits width) (let ((a (- cutoff k)) (y s)) (if (>= a 0) (dotimes (i a) (setq y (* y 10))) (dotimes (i (- a)) (setq y (ceiling y 10)))) (setq m- (max y m-)) (setq m+ (max y m+)) (when (= m+ y) (setq roundup t)))) (when (< (+ (ash r 1) m+) (ash s 1)) (return))) ;; Zero-fill before fraction if no integer part. (when (< k 0) (setq decpnt digits) (vector-push-extend #\. digit-string) (dotimes (i (- k)) (incf digits) (vector-push-extend #\0 digit-string))) ;; Generate the significant digits. (do ()(nil) (decf k) (when (= k -1) (vector-push-extend #\. digit-string) (setq decpnt digits)) (multiple-value-setq (u r) (truncate (* r 10) s)) (setq m- (* m- 10)) (setq m+ (* m+ 10)) (setq low (< (ash r 1) m-)) (if roundup (setq high (>= (ash r 1) (- (ash s 1) m+))) (setq high (> (ash r 1) (- (ash s 1) m+)))) ;; Stop when either precision is exhausted or we have printed as ;; many fraction digits as permitted. (when (or low high (and cutoff (<= k cutoff))) (return)) (vector-push-extend (char *digits* u) digit-string) (incf digits)) ;; If cutoff occurred before first digit, then no digits are ;; generated at all. (when (or (not cutoff) (>= k cutoff)) ;; Last digit may need rounding (vector-push-extend (char *digits* (cond ((and low (not high)) u) ((and high (not low)) (1+ u)) (t (if (<= (ash r 1) s) u (1+ u))))) digit-string) (incf digits)) ;; Zero-fill after integer part if no fraction. (when (>= k 0) (dotimes (i k) (incf digits) (vector-push-extend #\0 digit-string)) (vector-push-extend #\. digit-string) (setq decpnt digits)) ;; Add trailing zeroes to pad fraction if fdigits specified. (when fdigits (dotimes (i (- fdigits (- digits decpnt))) (incf digits) (vector-push-extend #\0 digit-string))) ;; all done (values digit-string (1+ digits) (= decpnt 0) (= decpnt digits) decpnt))) ;;; Given a non-negative floating point number, SCALE-EXPONENT returns ;;; a new floating point number Z in the range (0.1, 1.0] and an ;;; exponent E such that Z * 10^E is (approximately) equal to the ;;; original number. There may be some loss of precision due the ;;; floating point representation. The scaling is always done with ;;; long float arithmetic, which helps printing of lesser precisions ;;; as well as avoiding generic arithmetic. ;;; ;;; When computing our initial scale factor using EXPT, we pull out ;;; part of the computation to avoid over/under flow. When ;;; denormalized, we must pull out a large factor, since there is more ;;; negative exponent range than positive range. (defun scale-exponent (original-x) (let* ((x (coerce original-x 'long-float))) (multiple-value-bind (sig exponent) (decode-float x) (declare (ignore sig)) (if (= x 0.0l0) (values (float 0.0l0 original-x) 1) (let* ((ex (round (* exponent (log 2l0 10)))) (x (if (minusp ex) (if (float-denormalized-p x) #!-long-float (* x 1.0l16 (expt 10.0l0 (- (- ex) 16))) #!+long-float (* x 1.0l18 (expt 10.0l0 (- (- ex) 18))) (* x 10.0l0 (expt 10.0l0 (- (- ex) 1)))) (/ x 10.0l0 (expt 10.0l0 (1- ex)))))) (do ((d 10.0l0 (* d 10.0l0)) (y x (/ x d)) (ex ex (1+ ex))) ((< y 1.0l0) (do ((m 10.0l0 (* m 10.0l0)) (z y (* y m)) (ex ex (1- ex))) ((>= z 0.1l0) (values (float z original-x) ex)))))))))) ;;;; entry point for the float printer ;;; the float printer as called by PRINT, PRIN1, PRINC, etc. The ;;; argument is printed free-format, in either exponential or ;;; non-exponential notation, depending on its magnitude. ;;; ;;; NOTE: When a number is to be printed in exponential format, it is ;;; scaled in floating point. Since precision may be lost in this ;;; process, the guaranteed accuracy properties of FLONUM-TO-STRING ;;; are lost. The difficulty is that FLONUM-TO-STRING performs ;;; extensive computations with integers of similar magnitude to that ;;; of the number being printed. For large exponents, the bignums ;;; really get out of hand. If bignum arithmetic becomes reasonably ;;; fast and the exponent range is not too large, then it might become ;;; attractive to handle exponential notation with the same accuracy ;;; as non-exponential notation, using the method described in the ;;; Steele and White paper. ;;; Print the appropriate exponent marker for X and the specified exponent. (defun print-float-exponent (x exp stream) (declare (type float x) (type integer exp) (type stream stream)) (let ((*print-radix* nil) (plusp (plusp exp))) (if (typep x *read-default-float-format*) (unless (eql exp 0) (format stream "e~:[~;+~]~D" plusp exp)) (format stream "~C~:[~;+~]~D" (etypecase x (single-float #\f) (double-float #\d) (short-float #\s) (long-float #\L)) plusp exp)))) (defun output-float-infinity (x stream) (declare (float x) (stream stream)) (cond (*read-eval* (write-string "#." stream)) (*print-readably* (error 'print-not-readable :object x)) (t (write-string "#<" stream))) (write-string "SB-EXT:" stream) (write-string (symbol-name (float-format-name x)) stream) (write-string (if (plusp x) "-POSITIVE-" "-NEGATIVE-") stream) (write-string "INFINITY" stream) (unless *read-eval* (write-string ">" stream))) (defun output-float-nan (x stream) (print-unreadable-object (x stream) (princ (float-format-name x) stream) (write-string (if (float-trapping-nan-p x) " trapping" " quiet") stream) (write-string " NaN" stream))) ;;; the function called by OUTPUT-OBJECT to handle floats (defun output-float (x stream) (cond ((float-infinity-p x) (output-float-infinity x stream)) ((float-nan-p x) (output-float-nan x stream)) (t (let ((x (cond ((minusp (float-sign x)) (write-char #\- stream) (- x)) (t x)))) (cond ((zerop x) (write-string "0.0" stream) (print-float-exponent x 0 stream)) (t (output-float-aux x stream (float 1/1000 x) (float 10000000 x)))))))) (defun output-float-aux (x stream e-min e-max) (if (and (>= x e-min) (< x e-max)) ;; free format (multiple-value-bind (str len lpoint tpoint) (flonum-to-string x) (declare (ignore len)) (when lpoint (write-char #\0 stream)) (write-string str stream) (when tpoint (write-char #\0 stream)) (print-float-exponent x 0 stream)) ;; exponential format (multiple-value-bind (f ex) (scale-exponent x) (multiple-value-bind (str len lpoint tpoint) (flonum-to-string f nil nil 1) (declare (ignore len)) (when lpoint (write-char #\0 stream)) (write-string str stream) (when tpoint (write-char #\0 stream)) ;; Subtract out scale factor of 1 passed to FLONUM-TO-STRING. (print-float-exponent x (1- ex) stream))))) ;;;; other leaf objects ;;; If *PRINT-ESCAPE* is false, just do a WRITE-CHAR, otherwise output ;;; the character name or the character in the #\char format. (defun output-character (char stream) (if (or *print-escape* *print-readably*) (let ((name (char-name char))) (write-string "#\\" stream) (if name (quote-string name stream) (write-char char stream))) (write-char char stream))) (defun output-sap (sap stream) (declare (type system-area-pointer sap)) (cond (*read-eval* (format stream "#.(~S #X~8,'0X)" 'int-sap (sap-int sap))) (t (print-unreadable-object (sap stream) (format stream "system area pointer: #X~8,'0X" (sap-int sap)))))) (defun output-weak-pointer (weak-pointer stream) (declare (type weak-pointer weak-pointer)) (print-unreadable-object (weak-pointer stream) (multiple-value-bind (value validp) (weak-pointer-value weak-pointer) (cond (validp (write-string "weak pointer: " stream) (write value :stream stream)) (t (write-string "broken weak pointer" stream)))))) (defun output-code-component (component stream) (print-unreadable-object (component stream :identity t) (let ((dinfo (%code-debug-info component))) (cond ((eq dinfo :bogus-lra) (write-string "bogus code object" stream)) (t (write-string "code object" stream) (when dinfo (write-char #\space stream) (output-object (sb!c::debug-info-name dinfo) stream))))))) (defun output-lra (lra stream) (print-unreadable-object (lra stream :identity t) (write-string "return PC object" stream))) (defun output-fdefn (fdefn stream) (print-unreadable-object (fdefn stream) (write-string "FDEFINITION object for " stream) (output-object (fdefn-name fdefn) stream))) ;;;; functions ;;; Output OBJECT as using PRINT-OBJECT if it's a ;;; FUNCALLABLE-STANDARD-CLASS, or return NIL otherwise. ;;; ;;; The definition here is a simple temporary placeholder. It will be ;;; overwritten by a smarter version (capable of calling generic ;;; PRINT-OBJECT when appropriate) when CLOS is installed. (defun printed-as-clos-funcallable-standard-class (object stream) (declare (ignore object stream)) nil) (defun output-fun (object stream) (let* ((*print-length* 3) ; in case we have to.. (*print-level* 3) ; ..print an interpreted function definition ;; FIXME: This find-the-function-name idiom ought to be ;; encapsulated in a function somewhere. (name (case (fun-subtype object) (#.sb!vm:closure-header-widetag "CLOSURE") (#.sb!vm:simple-fun-header-widetag (%simple-fun-name object)) (t 'no-name-available))) (identified-by-name-p (and (symbolp name) (fboundp name) (eq (fdefinition name) object)))) (print-unreadable-object (object stream :identity (not identified-by-name-p)) (prin1 'function stream) (unless (eq name 'no-name-available) (format stream " ~S" name))))) ;;;; catch-all for unknown things (defun output-random (object stream) (print-unreadable-object (object stream :identity t) (let ((lowtag (lowtag-of object))) (case lowtag (#.sb!vm:other-pointer-lowtag (let ((widetag (widetag-of object))) (case widetag (#.sb!vm:value-cell-header-widetag (write-string "value cell " stream) (output-object (value-cell-ref object) stream)) (t (write-string "unknown pointer object, widetag=" stream) (let ((*print-base* 16) (*print-radix* t)) (output-integer widetag stream)))))) ((#.sb!vm:fun-pointer-lowtag #.sb!vm:instance-pointer-lowtag #.sb!vm:list-pointer-lowtag) (write-string "unknown pointer object, lowtag=" stream) (let ((*print-base* 16) (*print-radix* t)) (output-integer lowtag stream))) (t (case (widetag-of object) (#.sb!vm:unbound-marker-widetag (write-string "unbound marker" stream)) (t (write-string "unknown immediate object, lowtag=" stream) (let ((*print-base* 2) (*print-radix* t)) (output-integer lowtag stream)) (write-string ", widetag=" stream) (let ((*print-base* 16) (*print-radix* t)) (output-integer (widetag-of object) stream)))))))))