;;; print.lisp ---
;; Copyright (C) 2012, 2013 David Vazquez
;; Copyright (C) 2012 Raimon Grau
;; JSCL is free software: you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation, either version 3 of the
;; License, or (at your option) any later version.
;;
;; JSCL is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;; General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with JSCL. If not, see .
;;; Printer
;;; 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 &optional uppercase)
(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 #\:)
(and uppercase (not (char= ch (char (string-upcase (string ch)) 0))))
(char= 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 &optional uppercase)
(or (potential-number-p string)
(escape-symbol-name-p string uppercase)))
;;; Returns the token in a form that can be used for reading it back.
(defun escape-token (s &optional uppercase)
(if (escape-token-p s uppercase)
(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))
(defvar *print-escape* t)
(defun write-to-string (form)
(cond
((null form) "NIL")
((symbolp form)
(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)))
(escape-token (symbol-name form) (not (eq package *js-package*)))
;; Symbol is not accesible from *PACKAGE*, so let us prefix
;; the symbol with the optional package or uninterned mark.
(concat (cond
((null package) "#")
((eq package (find-package "KEYWORD")) "")
(t (escape-token (package-name package) t)))
":"
(if (and package
(eq (second (multiple-value-list
(find-symbol name package)))
:internal))
":"
"")
(escape-token name (not (eq package *js-package*)))))))
((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) (if *print-escape*
(concat "\"" (escape-string form) "\"")
form))
((functionp form)
(let ((name (oget form "fname")))
(if name
(concat "#")
(concat "#"))))
((listp form)
(concat "("
(join-trailing (mapcar #'write-to-string (butlast form)) " ")
(let ((last (last form)))
(if (null (cdr last))
(write-to-string (car last))
(concat (write-to-string (car last)) " . " (write-to-string (cdr last)))))
")"))
((arrayp form)
(concat "#" (if (zerop (length form))
"()"
(write-to-string (vector-to-list form)))))
((packagep form)
(concat "#"))
(t
(concat "#"))))
(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 write-line (x)
(write-string x)
(write-string *newline*)
x)
(defun warn (string)
(write-string "WARNING: ")
(write-line string))
(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 *newline*))
(t
(concatf res (format-special next (car arguments)))
(pop arguments))))
(setq res (concat res (char-to-string c))))
(incf i)))
(if destination
(progn
(write-string res)
nil)
res)))
(defun format-special (chr arg)
(case chr
(#\S (prin1-to-string arg))
(#\a (princ-to-string arg))))