-;;; print.lisp ---
-
-;; Copyright (C) 2012, 2013 David Vazquez
-;; Copyright (C) 2012 Raimon Grau
+;;; print.lisp ---
;; JSCL is free software: you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; You should have received a copy of the GNU General Public License
;; along with JSCL. If not, see <http://www.gnu.org/licenses/>.
+(/debug "loading print.lisp!")
+
;;; Printer
-(defun prin1-to-string (form)
- (cond
- ((symbolp form)
- (multiple-value-bind (symbol foundp)
- (find-symbol (symbol-name form) *package*)
- (if (and foundp (eq symbol form))
- (symbol-name form)
- (let ((package (symbol-package form))
- (name (symbol-name form)))
- (concat (cond
- ((null package) "#")
- ((eq package (find-package "KEYWORD")) "")
- (t (package-name package)))
- ":" name)))))
- ((integerp form) (integer-to-string form))
- ((floatp form) (float-to-string form))
- ((characterp form)
- (concat "#\\"
- (case form
- (#\newline "newline")
- (#\space "space")
- (otherwise (string form)))))
- ((stringp form) (concat "\"" (escape-string form) "\""))
- ((functionp form)
- (let ((name (oget form "fname")))
+(defun lisp-escape-string (string)
+ (let ((output "")
+ (index 0)
+ (size (length string)))
+ (while (< index size)
+ (let ((ch (char string index)))
+ (when (or (char= ch #\") (char= ch #\\))
+ (setq output (concat output "\\")))
+ (when (or (char= ch #\newline))
+ (setq output (concat output "\\"))
+ (setq ch #\n))
+ (setq output (concat output (string ch))))
+ (incf index))
+ (concat "\"" output "\"")))
+
+;;; Return T if the string S contains characters which need to be
+;;; escaped to print the symbol name, NIL otherwise.
+(defun escape-symbol-name-p (s)
+ (let ((dots-only t))
+ (dotimes (i (length s))
+ (let ((ch (char s i)))
+ (setf dots-only (and dots-only (char= ch #\.)))
+ (when (or (terminalp ch)
+ (char= ch #\:)
+ (char= ch #\\)
+ (not (char= ch (char-upcase ch)))
+ (char= ch #\|))
+ (return-from escape-symbol-name-p t))))
+ dots-only))
+
+;;; Return T if the specified string can be read as a number
+;;; In case such a string is the name of a symbol then escaping
+;;; is required when printing to ensure correct reading.
+(defun potential-number-p (string)
+ ;; The four rules for being a potential number are described in
+ ;; 2.3.1.1 Potential Numbers as Token
+ ;;
+ ;; First Rule
+ (dotimes (i (length string))
+ (let ((char (char string i)))
+ (cond
+ ;; Digits TODO: DIGIT-CHAR-P should work with the current
+ ;; radix here. If the radix is not decimal, then we have to
+ ;; make sure there is not a decimal-point in the string.
+ ((digit-char-p char))
+ ;; Signs, ratios, decimal point and extension mark
+ ((find char "+-/._^"))
+ ;; Number marker
+ ((alpha-char-p char)
+ (when (and (< i (1- (length string)))
+ (alpha-char-p (char string (1+ i))))
+ ;; fail: adjacent letters are not number marker, or
+ ;; there is a decimal point in the string.
+ (return-from potential-number-p)))
+ (t
+ ;; fail: there is a non-allowed character
+ (return-from potential-number-p)))))
+ (and
+ ;; Second Rule. In particular string is not empty.
+ (find-if #'digit-char-p string)
+ ;; Third rule
+ (let ((first (char string 0)))
+ (and (not (char= first #\:))
+ (or (digit-char-p first)
+ (find first "+-._^"))))
+ ;; Fourth rule
+ (not (find (char string (1- (length string))) "+-)"))))
+
+#+nil
+(mapcar #'potential-number-p
+ '("1b5000" "777777q" "1.7J" "-3/4+6.7J" "12/25/83" "27^19"
+ "3^4/5" "6//7" "3.1.2.6" "^-43^" "3.141_592_653_589_793_238_4"
+ "-3.7+2.6i-6.17j+19.6k"))
+
+#+nil
+(mapcar #'potential-number-p '("/" "/5" "+" "1+" "1-" "foo+" "ab.cd" "_" "^" "^/-"))
+
+(defun escape-token-p (string)
+ (or (potential-number-p string)
+ (escape-symbol-name-p string)))
+
+;;; Returns the token in a form that can be used for reading it back.
+(defun escape-token (s)
+ (if (escape-token-p s)
+ (let ((result "|"))
+ (dotimes (i (length s))
+ (let ((ch (char s i)))
+ (when (or (char= ch #\|)
+ (char= ch #\\))
+ (setf result (concat result "\\")))
+ (setf result (concat result (string ch)))))
+ (concat result "|"))
+ s))
+
+#+jscl (defvar *print-escape* t)
+#+jscl (defvar *print-circle* nil)
+
+;; To support *print-circle* some objects must be tracked for sharing:
+;; conses, arrays and apparently-uninterned symbols. These objects
+;; are placed in an array and a parallel array is used to mark if
+;; they're found multiple times by assining them an id starting from
+;; 1.
+;;
+;; After the tracking has been completed the printing phase can begin:
+;; if an object has an id > 0 then #<n>= is prefixed and the id is
+;; changed to negative. If an object has an id < 0 then #<-n># is
+;; printed instead of the object.
+;;
+;; The processing is O(n^2) with n = number of tracked
+;; objects. Hopefully it will become good enough when the new compiler
+;; is available.
+(defun scan-multiple-referenced-objects (form)
+ (let ((known-objects (make-array 0 :adjustable t :fill-pointer 0))
+ (object-ids (make-array 0 :adjustable t :fill-pointer 0)))
+ (vector-push-extend nil known-objects)
+ (vector-push-extend 0 object-ids)
+ (let ((count 0))
+ (labels ((mark (x)
+ (let ((i (position x known-objects)))
+ (cond
+ ((null i)
+ (vector-push-extend x known-objects)
+ (vector-push-extend 0 object-ids)
+ t)
+ (t
+ (setf (aref object-ids i) (incf count))
+ nil))))
+ (visit (x)
+ (cond
+ ((and x (symbolp x) (null (symbol-package x)))
+ (mark x))
+ ((consp x)
+ (when (mark x)
+ (visit (car x))
+ (visit (cdr x))))
+ ((vectorp x)
+ (when (mark x)
+ (dotimes (i (length x))
+ (visit (aref x i))))))))
+ (visit form)))
+ (values known-objects object-ids)))
+
+;;; Write an integer to stream.
+;;; TODO: Support for different basis.
+(defun write-integer (value stream)
+ (write-string (integer-to-string value) stream))
+
+;;; This version of format supports only ~A for strings and ~D for
+;;; integers. It is used to avoid circularities. Indeed, it just
+;;; ouputs to streams.
+(defun simple-format (stream fmt &rest args)
+ (do ((i 0 (1+ i)))
+ ((= i (length fmt)))
+ (let ((char (char fmt i)))
+ (if (char= char #\~)
+ (let ((next (if (< i (1- (length fmt)))
+ (char fmt (1+ i))
+ (error "`~~' appears in the last position of the format control string ~S." fmt))))
+ (ecase next
+ (#\~ (write-char #\~ stream))
+ (#\d (write-integer (pop args) stream))
+ (#\a (write-string (pop args) stream)))
+ (incf i))
+ (write-char char stream)))))
+
+
+(defun write-aux (form stream known-objects object-ids)
+ (when *print-circle*
+ (let* ((ix (or (position form known-objects) 0))
+ (id (aref object-ids ix)))
+ (cond
+ ((and id (> id 0))
+ (simple-format stream "#~d=" id)
+ (setf (aref object-ids id) (- id)))
+ ((and id (< id 0))
+ (simple-format stream "#~d#" (- id))
+ (return-from write-aux)))))
+ (typecase form
+ ;; NIL
+ (null
+ (write-string "NIL" stream))
+ ;; Symbols
+ (symbol
+ (let ((name (symbol-name form))
+ (package (symbol-package form)))
+ ;; Check if the symbol is accesible from the current package. It
+ ;; is true even if the symbol's home package is not the current
+ ;; package, because it could be inherited.
+ (if (eq form (find-symbol (symbol-name form)))
+ (write-string (escape-token (symbol-name form)) stream)
+ ;; Symbol is not accesible from *PACKAGE*, so let us prefix
+ ;; the symbol with the optional package or uninterned mark.
+ (progn
+ (cond
+ ((null package) (write-char #\# stream))
+ ((eq package (find-package "KEYWORD")))
+ (t (write-char (escape-token (package-name package)) stream)))
+ (write-char #\: stream)
+ (let ((symbtype (and package (second (multiple-value-list (find-symbol name package))))))
+ (when (and package (eq symbtype :internal))
+ (write-char #\: stream)))
+ (write-string (escape-token name) stream)))))
+ ;; Integers
+ (integer
+ (write-integer form stream))
+ ;; Floats
+ (float
+ (write-string (float-to-string form) stream))
+ ;; Characters
+ (character
+ (write-string "#\\" stream)
+ (case form
+ (#\newline (write-string "newline" stream))
+ (#\space (write-string "space" stream))
+ (otherwise (write-char form stream))))
+ ;; Strings
+ (string
+ (if *print-escape*
+ (write-string (lisp-escape-string form) stream)
+ (write-string form stream)))
+ ;; Functions
+ (function
+ (let ((name #+jscl (oget form "fname")
+ #-jscl nil))
(if name
- (concat "#<FUNCTION " name ">")
- (concat "#<FUNCTION>"))))
- ((listp form)
- (concat "("
- (join-trailing (mapcar #'prin1-to-string (butlast form)) " ")
- (let ((last (last form)))
- (if (null (cdr last))
- (prin1-to-string (car last))
- (concat (prin1-to-string (car last)) " . " (prin1-to-string (cdr last)))))
- ")"))
- ((arrayp form)
- (concat "#" (if (zerop (length form))
- "()"
- (prin1-to-string (vector-to-list form)))))
- ((packagep form)
- (concat "#<PACKAGE " (package-name form) ">"))
- (t
- (concat "#<javascript object>"))))
+ (simple-format stream "#<FUNCTION ~a>" name)
+ (write-string "#<FUNCTION>" stream))))
+ ;; Lists
+ (list
+ (write-char #\( stream)
+ (unless (null form)
+ (write-aux (car form) stream known-objects object-ids)
+ (do ((tail (cdr form) (cdr tail)))
+ ;; Stop on symbol OR if the object is already known when we
+ ;; accept circular printing.
+ ((or (atom tail)
+ (and *print-circle*
+ (let* ((ix (or (position tail known-objects) 0))
+ (id (aref object-ids ix)))
+ (not (zerop id)))))
+ (unless (null tail)
+ (write-string " . " stream)
+ (write-aux tail stream known-objects object-ids)))
+ (write-char #\space stream)
+ (write-aux (car tail) stream known-objects object-ids)))
+ (write-char #\) stream))
+ ;; Vectors
+ (vector
+ (write-string "#(" stream)
+ (when (plusp (length form))
+ (write-aux (aref form 0) stream known-objects object-ids)
+ (do ((i 1 (1+ i)))
+ ((= i (length form)))
+ (write-char #\space stream)
+ (write-aux (aref form i) stream known-objects object-ids)))
+ (write-char #\) stream))
+ ;; Packages
+ (package
+ (simple-format stream "#<PACKAGE ~a>" (package-name form)))
+ ;; Others
+ (otherwise
+ (write-string "#<javascript object>" stream))))
+
-(defun write-line (x)
- (write-string x)
- (write-string *newline*)
- x)
+#+jscl
+(defun write (form &key (stream *standard-output*))
+ (write-aux form stream))
-(defun warn (string)
- (write-string "WARNING: ")
- (write-line string))
+(defun !write-to-string (form)
+ (with-output-to-string (output)
+ (multiple-value-bind (objs ids)
+ (scan-multiple-referenced-objects form)
+ (write-aux form output objs ids))))
+#+jscl (fset 'write-to-string (fdefinition '!write-to-string))
+
+#+jscl
+(progn
+
+ (defun prin1-to-string (form)
+ (let ((*print-escape* t))
+ (write-to-string form)))
+
+ (defun princ-to-string (form)
+ (let ((*print-escape* nil))
+ (write-to-string form)))
+
+ (defun terpri ()
+ (write-char #\newline)
+ (values))
+
+ (defun write-line (x)
+ (write-string x)
+ (terpri)
+ x)
+
+ (defun warn (fmt &rest args)
+ (write-string "WARNING: ")
+ (apply #'format t fmt args)
+ (terpri))
+
+ (defun print (x)
+ (write-line (prin1-to-string x))
+ x))
+
+;;; Format
+
+(defun format-special (chr arg)
+ (case (char-upcase chr)
+ (#\S (prin1-to-string arg))
+ (#\A (princ-to-string arg))
+ (#\D (princ-to-string arg))
+ (t
+ (warn "~S is not implemented yet, using ~~S instead" chr)
+ (prin1-to-string arg))))
-(defun print (x)
- (write-line (prin1-to-string x))
- x)
+(defun !format (destination fmt &rest args)
+ (let ((len (length fmt))
+ (i 0)
+ (res "")
+ (arguments args))
+ (while (< i len)
+ (let ((c (char fmt i)))
+ (if (char= c #\~)
+ (let ((next (char fmt (incf i))))
+ (cond
+ ((char= next #\~)
+ (concatf res "~"))
+ ((char= next #\%)
+ (concatf res (string #\newline)))
+ ((char= next #\*)
+ (pop arguments))
+ (t
+ (concatf res (format-special next (car arguments)))
+ (pop arguments))))
+ (setq res (concat res (string c))))
+ (incf i)))
+ (if destination
+ (progn
+ (write-string res)
+ nil)
+ res)))
+#+jscl (fset 'format (fdefinition '!format))
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