;;;; 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*) #!+sb-doc (setf (fdocumentation '*print-pprint-dispatch* 'variable) "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 ;;; keyword variables shared by WRITE and WRITE-TO-STRING, and ;;; the bindings they map to. (eval-when (:compile-toplevel :load-toplevel) (defvar *printer-keyword-variables* '(:escape *print-escape* :radix *print-radix* :base *print-base* :circle *print-circle* :pretty *print-pretty* :level *print-level* :length *print-length* :case *print-case* :array *print-array* :gensym *print-gensym* :readably *print-readably* :right-margin *print-right-margin* :miser-width *print-miser-width* :lines *print-lines* :pprint-dispatch *print-pprint-dispatch*))) (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) ;;; Optimize common case of constant keyword arguments (define-compiler-macro write (&whole form object &rest keys) (let (bind ignore) (do () ((not (cdr keys)) ;; Odd number of keys, punt (when keys (return-from write form))) (let* ((key (pop keys)) (value (pop keys)) (variable (or (getf *printer-keyword-variables* key) (when (eq :stream key) 'stream) (return-from write form)))) (when (assoc variable bind) ;; First key has precedence, but we still need to execute the ;; argument, and in the right order. (setf variable (gensym "IGNORE")) (push variable ignore)) (push (list variable value) bind))) (unless (assoc 'stream bind) (push (list 'stream '*standard-output*) bind)) `(let ,(nreverse bind) ,@(when ignore `((declare (ignore ,@ignore)))) (output-object ,object stream)))) (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)) ;;; Optimize common case of constant keyword arguments (define-compiler-macro write-to-string (&whole form object &rest keys) (let (bind ignore) (do () ((not (cdr keys)) ;; Odd number of keys, punt (when keys (return-from write-to-string form))) (let* ((key (pop keys)) (value (pop keys)) (variable (or (getf *printer-keyword-variables* key) (return-from write-to-string form)))) (when (assoc variable bind) ;; First key has precedence, but we still need to execute the ;; argument, and in the right order. (setf variable (gensym "IGNORE")) (push variable ignore)) (push (list variable value) bind))) (if bind `(let ,(nreverse bind) ,@(when ignore `((declare (ignore ,@ignore)))) (stringify-object ,object)) `(stringify-object ,object)))) (defun prin1-to-string (object) #!+sb-doc "Return the printed representation of OBJECT as a string with slashification on." (let ((*print-escape* t)) (stringify-object object))) (defun princ-to-string (object) #!+sb-doc "Return the printed representation of OBJECT as a string with slashification off." (let ((*print-escape* nil) (*print-readably* nil)) (stringify-object object))) ;;; This produces the printed representation of an object as a string. ;;; The few ...-TO-STRING functions above call this. (defun stringify-object (object) (let ((stream (make-string-output-stream))) (setup-printer-state) (output-object object stream) (get-output-stream-string stream))) ;;;; 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) (write-char #\space stream)) (when body (funcall body)) (when identity (when (or body (not type)) (write-char #\space 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) ;;;; 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) (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 (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)))) (funcallable-instance (cond ((not (and (boundp '*print-object-is-disabled-p*) *print-object-is-disabled-p*)) (print-object object stream)) (t (output-fun object stream)))) (function (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)) (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-string name)) (let ((*readtable* (if *print-readably* *standard-readtable* *readtable*))) (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 160 ; FIXME :element-type '(unsigned-byte 16) :initial-element 0)) (declaim (type (simple-array (unsigned-byte 16) (#.160)) ; FIXME *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 160) ; FIXME (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 128 ; FIXME :element-type '(unsigned-byte 8) :initial-element 36)) (declaim (type (simple-array (unsigned-byte 8) (#.128)) ; FIXME *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 (cond ; FIXME ((< code 160) (aref attributes code)) ((upper-case-p current) uppercase-attribute) ((lower-case-p current) lowercase-attribute) (t other-attribute))) (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 () `(and (< code 128) ; FIXME (< (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 (let* ((char (schar name i)) (code (char-code char))) (cond ((< code 160) (aref attributes code)) ((upper-case-p char) uppercase-attribute) ((lower-case-p char) lowercase-attribute) (t other-attribute))) 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... ;; ("What," you may ask, "is a 'number marker'?" It's something ;; that a conforming implementation might use in number syntax. ;; See ANSI 2.3.1.1 "Potential Numbers as Tokens".) (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-alphanum t) (up (eq (readtable-case *readtable*) :upcase))) (dotimes (i (length pname)) (let ((char (char pname i))) (write-char (if up (if (or prev-not-alphanum (lower-case-p char)) char (char-downcase char)) (if prev-not-alphanum (char-upcase char) char)) stream) (setq prev-not-alphanum (not (alphanumericp 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 ((and *print-readably* (not (eq (array-element-type vector) (load-time-value (array-element-type (make-array 0 :element-type 'character)))))) (error 'print-not-readable :object vector)) ((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 vector))) (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) :check-fill-pointer t) (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) (*print-radix* nil)) (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-radix (base stream) (write-char #\# stream) (write-char (case base (2 #\b) (8 #\o) (16 #\x) (t (%output-reasonable-integer-in-base base 10 stream) #\r)) stream)) (defun %output-reasonable-integer-in-base (n base stream) (multiple-value-bind (q r) (truncate n base) ;; Recurse until you have all the digits pushed on ;; the stack. (unless (zerop q) (%output-reasonable-integer-in-base q base stream)) ;; Then as each recursive call unwinds, turn the ;; digit (in remainder) into a character and output ;; the character. (write-char (schar "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" r) stream))) ;;; *POWER-CACHE* is an alist mapping bases to power-vectors. It is ;;; filled and probed by POWERS-FOR-BASE. SCRUB-POWER-CACHE is called ;;; always prior a GC to drop overly large bignums from the cache. ;;; ;;; It doesn't need a lock, but if you work on SCRUB-POWER-CACHE or ;;; POWERS-FOR-BASE, see that you don't break the assumptions! (defvar *power-cache* nil) (defconstant +power-cache-integer-length-limit+ 2048) (defun scrub-power-cache () (let ((cache *power-cache*)) (dolist (cell cache) (let ((powers (cdr cell))) (declare (simple-vector powers)) (let ((too-big (position-if (lambda (x) (>= (integer-length x) +power-cache-integer-length-limit+)) powers))) (when too-big (setf (cdr cell) (subseq powers 0 too-big)))))) ;; Since base 10 is overwhelmingly common, make sure it's at head. ;; Try to keep other bases in a hopefully sensible order as well. (if (eql 10 (caar cache)) (setf *power-cache* cache) ;; If we modify the list destructively we need to copy it, otherwise ;; an alist lookup in progress might be screwed. (setf *power-cache* (sort (copy-list cache) (lambda (a b) (declare (fixnum a b)) (cond ((= 10 a) t) ((= 10 b) nil) ((= 16 a) t) ((= 16 b) nil) ((= 2 a) t) ((= 2 b) nil) (t (< a b)))) :key #'car))))) ;;; Compute (and cache) a power vector for a BASE and LIMIT: ;;; the vector holds integers for which ;;; (aref powers k) == (expt base (expt 2 k)) ;;; holds. (defun powers-for-base (base limit) (flet ((compute-powers (from) (let (powers) (do ((p from (* p p))) ((> p limit) ;; We don't actually need this, but we also ;; prefer not to cons it up a second time... (push p powers)) (push p powers)) (nreverse powers)))) ;; Grab a local reference so that we won't stuff consed at the ;; head by other threads -- or sorting by SCRUB-POWER-CACHE. (let ((cache *power-cache*)) (let ((cell (assoc base cache))) (if cell (let* ((powers (cdr cell)) (len (length powers)) (max (svref powers (1- len)))) (if (> max limit) powers (let ((new (concatenate 'vector powers (compute-powers (* max max))))) (setf (cdr cell) new) new))) (let ((powers (coerce (compute-powers base) 'vector))) ;; Add new base to head: SCRUB-POWER-CACHE will later ;; put it to a better place. (setf *power-cache* (acons base powers cache)) powers)))))) ;; Algorithm by Harald Hanche-Olsen, sbcl-devel 2005-02-05 (defun %output-huge-integer-in-base (n base stream) (declare (type bignum n) (type fixnum base)) ;; POWER is a vector for which the following holds: ;; (aref power k) == (expt base (expt 2 k)) (let* ((power (powers-for-base base n)) (k-start (or (position-if (lambda (x) (> x n)) power) (bug "power-vector too short")))) (labels ((bisect (n k exactp) (declare (fixnum k)) ;; N is the number to bisect ;; K on initial entry BASE^(2^K) > N ;; EXACTP is true if 2^K is the exact number of digits (cond ((zerop n) (when exactp (loop repeat (ash 1 k) do (write-char #\0 stream)))) ((zerop k) (write-char (schar "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" n) stream)) (t (setf k (1- k)) (multiple-value-bind (q r) (truncate n (aref power k)) ;; EXACTP is NIL only at the head of the ;; initial number, as we don't know the number ;; of digits there, but we do know that it ;; doesn't get any leading zeros. (bisect q k exactp) (bisect r k (or exactp (plusp q)))))))) (bisect n k-start nil)))) (defun %output-integer-in-base (integer base stream) (when (minusp integer) (write-char #\- stream) (setf integer (- integer))) ;; The ideal cutoff point between these two algorithms is almost ;; certainly quite platform dependent: this gives 87 for 32 bit ;; SBCL, which is about right at least for x86/Darwin. (if (or (fixnump integer) (< (integer-length integer) (* 3 sb!vm:n-positive-fixnum-bits))) (%output-reasonable-integer-in-base integer base stream) (%output-huge-integer-in-base integer base stream))) (defun output-integer (integer stream) (let ((base *print-base*)) (when (and (/= base 10) *print-radix*) (%output-radix base stream)) (%output-integer-in-base integer base stream) (when (and *print-radix* (= base 10)) (write-char #\. stream)))) (defun output-ratio (ratio stream) (let ((base *print-base*)) (when *print-radix* (%output-radix base stream)) (%output-integer-in-base (numerator ratio) base stream) (write-char #\/ stream) (%output-integer-in-base (denominator ratio) base stream))) (defun output-complex (complex stream) (write-string "#C(" stream) ;; FIXME: Could this just be OUTPUT-NUMBER? (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 ;;; 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. ;;; ;;; 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-DIGITS actually generates the digits for positive numbers; ;;; see below for comments. (defun flonum-to-string (x &optional width fdigits scale fmin) (declare (type float x)) ;; FIXME: I think only FORMAT-DOLLARS calls FLONUM-TO-STRING with ;; possibly-negative X. (setf x (abs x)) (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 (e string) (if fdigits (flonum-to-digits x (min (- (+ fdigits (or scale 0))) (- (or fmin 0)))) (if (and width (> width 1)) (let ((w (multiple-value-list (flonum-to-digits x (max 1 (+ (1- width) (if (and scale (minusp scale)) scale 0))) t))) (f (multiple-value-list (flonum-to-digits x (- (+ (or fmin 0) (if scale scale 0))))))) (cond ((>= (length (cadr w)) (length (cadr f))) (values-list w)) (t (values-list f)))) (flonum-to-digits x))) (let ((e (+ e (or scale 0))) (stream (make-string-output-stream))) (if (plusp e) (progn (write-string string stream :end (min (length string) e)) (dotimes (i (- e (length string))) (write-char #\0 stream)) (write-char #\. stream) (write-string string stream :start (min (length string) e)) (when fdigits (dotimes (i (- fdigits (- (length string) (min (length string) e)))) (write-char #\0 stream)))) (progn (write-string "." stream) (dotimes (i (- e)) (write-char #\0 stream)) (write-string string stream) (when fdigits (dotimes (i (+ fdigits e (- (length string)))) (write-char #\0 stream))))) (let ((string (get-output-stream-string stream))) (values string (length string) (char= (char string 0) #\.) (char= (char string (1- (length string))) #\.) (position #\. string)))))))) ;;; implementation of figure 1 from Burger and Dybvig, 1996. As the ;;; implementation of the Dragon from Classic CMUCL (and previously in ;;; SBCL above FLONUM-TO-STRING) says: "DO NOT EVEN THINK OF ;;; ATTEMPTING TO UNDERSTAND THIS CODE WITHOUT READING THE PAPER!", ;;; and in this case we have to add that even reading the paper might ;;; not bring immediate illumination as CSR has attempted to turn ;;; idiomatic Scheme into idiomatic Lisp. ;;; ;;; FIXME: figure 1 from Burger and Dybvig is the unoptimized ;;; algorithm, noticeably slow at finding the exponent. Figure 2 has ;;; an improved algorithm, but CSR ran out of energy. ;;; ;;; possible extension for the enthusiastic: printing floats in bases ;;; other than base 10. (defconstant single-float-min-e (- 2 sb!vm:single-float-bias sb!vm:single-float-digits)) (defconstant double-float-min-e (- 2 sb!vm:double-float-bias sb!vm:double-float-digits)) #!+long-float (defconstant long-float-min-e (nth-value 1 (decode-float least-positive-long-float))) (defun flonum-to-digits (v &optional position relativep) (let ((print-base 10) ; B (float-radix 2) ; b (float-digits (float-digits v)) ; p (digit-characters "0123456789") (min-e (etypecase v (single-float single-float-min-e) (double-float double-float-min-e) #!+long-float (long-float long-float-min-e)))) (multiple-value-bind (f e) (integer-decode-float v) (let (;; FIXME: these even tests assume normal IEEE rounding ;; mode. I wonder if we should cater for non-normal? (high-ok (evenp f)) (low-ok (evenp f))) (with-push-char (:element-type base-char) (labels ((scale (r s m+ m-) (do ((k 0 (1+ k)) (s s (* s print-base))) ((not (or (> (+ r m+) s) (and high-ok (= (+ r m+) s)))) (do ((k k (1- k)) (r r (* r print-base)) (m+ m+ (* m+ print-base)) (m- m- (* m- print-base))) ((not (or (< (* (+ r m+) print-base) s) (and (not high-ok) (= (* (+ r m+) print-base) s)))) (values k (generate r s m+ m-))))))) (generate (r s m+ m-) (let (d tc1 tc2) (tagbody loop (setf (values d r) (truncate (* r print-base) s)) (setf m+ (* m+ print-base)) (setf m- (* m- print-base)) (setf tc1 (or (< r m-) (and low-ok (= r m-)))) (setf tc2 (or (> (+ r m+) s) (and high-ok (= (+ r m+) s)))) (when (or tc1 tc2) (go end)) (push-char (char digit-characters d)) (go loop) end (let ((d (cond ((and (not tc1) tc2) (1+ d)) ((and tc1 (not tc2)) d) (t ; (and tc1 tc2) (if (< (* r 2) s) d (1+ d)))))) (push-char (char digit-characters d)) (return-from generate (get-pushed-string)))))) (initialize () (let (r s m+ m-) (if (>= e 0) (let* ((be (expt float-radix e)) (be1 (* be float-radix))) (if (/= f (expt float-radix (1- float-digits))) (setf r (* f be 2) s 2 m+ be m- be) (setf r (* f be1 2) s (* float-radix 2) m+ be1 m- be))) (if (or (= e min-e) (/= f (expt float-radix (1- float-digits)))) (setf r (* f 2) s (* (expt float-radix (- e)) 2) m+ 1 m- 1) (setf r (* f float-radix 2) s (* (expt float-radix (- 1 e)) 2) m+ float-radix m- 1))) (when position (when relativep (aver (> position 0)) (do ((k 0 (1+ k)) ;; running out of letters here (l 1 (* l print-base))) ((>= (* s l) (+ r m+)) ;; k is now \hat{k} (if (< (+ r (* s (/ (expt print-base (- k position)) 2))) (* s (expt print-base k))) (setf position (- k position)) (setf position (- k position 1)))))) (let ((low (max m- (/ (* s (expt print-base position)) 2))) (high (max m+ (/ (* s (expt print-base position)) 2)))) (when (<= m- low) (setf m- low) (setf low-ok t)) (when (<= m+ high) (setf m+ high) (setf high-ok t)))) (values r s m+ m-)))) (multiple-value-bind (r s m+ m-) (initialize) (scale r s m+ m-)))))))) ;;; 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. (eval-when (:compile-toplevel :execute) (setf *read-default-float-format* #!+long-float 'long-float #!-long-float 'double-float)) (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 0.0e0) (values (float 0.0e0 original-x) 1) (let* ((ex (locally (declare (optimize (safety 0))) (the fixnum (round (* exponent ;; this is the closest double float ;; to (log 2 10), but expressed so ;; that we're not vulnerable to the ;; host lisp's interpretation of ;; arithmetic. (FIXME: it turns ;; out that sbcl itself is off by 1 ;; ulp in this value, which is a ;; little unfortunate.) (load-time-value #!-long-float (sb!kernel:make-double-float 1070810131 1352628735) #!+long-float (error "(log 2 10) not computed"))))))) (x (if (minusp ex) (if (float-denormalized-p x) #!-long-float (* x 1.0e16 (expt 10.0e0 (- (- ex) 16))) #!+long-float (* x 1.0e18 (expt 10.0e0 (- (- ex) 18))) (* x 10.0e0 (expt 10.0e0 (- (- ex) 1)))) (/ x 10.0e0 (expt 10.0e0 (1- ex)))))) (do ((d 10.0e0 (* d 10.0e0)) (y x (/ x d)) (ex ex (1+ ex))) ((< y 1.0e0) (do ((m 10.0e0 (* m 10.0e0)) (z y (* y m)) (ex ex (1- ex))) ((>= z 0.1e0) (values (float z original-x) ex)) (declare (long-float m) (integer ex)))) (declare (long-float d)))))))) (eval-when (:compile-toplevel :execute) (setf *read-default-float-format* 'single-float)) ;;;; 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. ;;; ;;; NOTE II: this has been bypassed slightly by implementing Burger ;;; and Dybvig, 1996. When someone has time (KLUDGE) they can ;;; probably (a) implement the optimizations suggested by Burger and ;;; Dyvbig, and (b) remove all vestiges of Dragon4, including from ;;; fixed-format printing. ;;; 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)) (if (typep x *read-default-float-format*) (unless (eql exp 0) (format stream "e~D" exp)) (format stream "~C~D" (etypecase x (single-float #\f) (double-float #\d) (short-float #\s) (long-float #\L)) 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 -3 8))))))) (defun output-float-aux (x stream e-min e-max) (multiple-value-bind (e string) (flonum-to-digits x) (cond ((< e-min e e-max) (if (plusp e) (progn (write-string string stream :end (min (length string) e)) (dotimes (i (- e (length string))) (write-char #\0 stream)) (write-char #\. stream) (write-string string stream :start (min (length string) e)) (when (<= (length string) e) (write-char #\0 stream)) (print-float-exponent x 0 stream)) (progn (write-string "0." stream) (dotimes (i (- e)) (write-char #\0 stream)) (write-string string stream) (print-float-exponent x 0 stream)))) (t (write-string string stream :end 1) (write-char #\. stream) (write-string string stream :start 1) (print-float-exponent x (1- e) 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 ((graphicp (and (graphic-char-p char) (standard-char-p char))) (name (char-name char))) (write-string "#\\" stream) (if (and name (not graphicp)) (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-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 (name (%fun-name object)) (proper-name-p (and (legal-fun-name-p name) (fboundp name) (eq (fdefinition name) object)))) (print-unreadable-object (object stream :identity (not proper-name-p)) (format stream "~:[FUNCTION~;CLOSURE~]~@[ ~S~]" (closurep object) 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)))))))))