;;;; character functions ;;;; ;;;; This implementation assumes the use of ASCII codes and the ;;;; specific character formats used in SBCL (and its ancestor, CMU ;;;; CL). It is optimized for performance rather than for portability ;;;; and elegance, and may have to be rewritten if the character ;;;; representation is changed. ;;;; ;;;; KLUDGE: As of sbcl-0.6.11.25, at least, the ASCII-dependence is ;;;; not confined to this file. E.g. there are DEFTRANSFORMs in ;;;; srctran.lisp for CHAR-UPCASE, CHAR-EQUAL, and CHAR-DOWNCASE, and ;;;; they assume ASCII. -- WHN 2001-03-25 ;;;; 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") ;;; We compile some trivial character operations via inline expansion. #!-sb-fluid (declaim (inline standard-char-p graphic-char-p alpha-char-p upper-case-p lower-case-p both-case-p alphanumericp char-int)) (declaim (maybe-inline digit-char-p digit-weight)) (deftype char-code () `(integer 0 (,char-code-limit))) ;;; This is the alist of (character-name . character) for characters ;;; with long names. The first name in this list for a given character ;;; is used on typeout and is the preferred form for input. (macrolet ((frob (char-names-list) (collect ((results)) (dolist (code char-names-list) (destructuring-bind (ccode names) code (dolist (name names) (results (cons name (code-char ccode)))))) `(defparameter *char-name-alist* ',(results))))) ;; Note: The *** markers here indicate character names which are ;; required by the ANSI specification of #'CHAR-NAME. For the others, ;; we prefer the ASCII standard name. (frob ((#x00 ("Nul" "Null" "^@")) (#x01 ("Soh" "^a")) (#x02 ("Stx" "^b")) (#x03 ("Etx" "^c")) (#x04 ("Eot" "^d")) (#x05 ("Enq" "^e")) (#x06 ("Ack" "^f")) (#x07 ("Bel" "Bell" "^g")) (#x08 ("Backspace" "^h" "Bs")) ; *** See Note above. (#x09 ("Tab" "^i" "Ht")) ; *** See Note above. (#x0A ("Newline" "Linefeed" "^j" "Lf" "Nl" )) ; *** See Note above. (#x0B ("Vt" "^k")) (#x0C ("Page" "^l" "Form" "Formfeed" "Ff" "Np")) ; *** See Note above. (#x0D ("Return" "^m" "Cr")) ; *** See Note above. (#x0E ("So" "^n")) (#x0F ("Si" "^o")) (#x10 ("Dle" "^p")) (#x11 ("Dc1" "^q")) (#x12 ("Dc2" "^r")) (#x13 ("Dc3" "^s")) (#x14 ("Dc4" "^t")) (#x15 ("Nak" "^u")) (#x16 ("Syn" "^v")) (#x17 ("Etb" "^w")) (#x18 ("Can" "^x")) (#x19 ("Em" "^y")) (#x1A ("Sub" "^z")) (#x1B ("Esc" "Escape" "^[" "Altmode" "Alt")) (#x1C ("Fs" "^\\")) (#x1D ("Gs" "^]")) (#x1E ("Rs" "^^")) (#x1F ("Us" "^_")) (#x20 ("Space" "Sp")) ; *** See Note above. (#x7f ("Rubout" "Delete" "Del"))))) ; *** See Note above. ;;;; accessor functions (defun char-code (char) #!+sb-doc "Return the integer code of CHAR." (etypecase char (base-char (char-code (truly-the base-char char))))) (defun char-int (char) #!+sb-doc "Return the integer code of CHAR. (In SBCL this is the same as CHAR-CODE, as there are no character bits or fonts.)" (char-code char)) (defun code-char (code) #!+sb-doc "Return the character with the code CODE." (code-char code)) (defun character (object) #!+sb-doc "Coerce OBJECT into a CHARACTER if possible. Legal inputs are characters, strings and symbols of length 1." (flet ((do-error (control args) (error 'simple-type-error :datum object ;;?? how to express "symbol with name of length 1"? :expected-type '(or character (string 1)) :format-control control :format-arguments args))) (typecase object (character object) (string (if (= 1 (length (the string object))) (char object 0) (do-error "String is not of length one: ~S" (list object)))) (symbol (if (= 1 (length (symbol-name object))) (schar (symbol-name object) 0) (do-error "Symbol name is not of length one: ~S" (list object)))) (t (do-error "~S cannot be coerced to a character." (list object)))))) (defun char-name (char) #!+sb-doc "Return the name (a STRING) for a CHARACTER object." (car (rassoc char *char-name-alist*))) (defun name-char (name) #!+sb-doc "Given an argument acceptable to STRING, NAME-CHAR returns a character whose name is that string, if one exists. Otherwise, NIL is returned." (cdr (assoc (string name) *char-name-alist* :test #'string-equal))) ;;;; predicates (defun standard-char-p (char) #!+sb-doc "The argument must be a character object. STANDARD-CHAR-P returns T if the argument is a standard character -- one of the 95 ASCII printing characters or ." (and (typep char 'base-char) (let ((n (char-code (the base-char char)))) (or (< 31 n 127) (= n 10))))) (defun %standard-char-p (thing) #!+sb-doc "Return T if and only if THING is a standard-char. Differs from STANDARD-CHAR-P in that THING doesn't have to be a character." (and (characterp thing) (standard-char-p thing))) (defun graphic-char-p (char) #!+sb-doc "The argument must be a character object. GRAPHIC-CHAR-P returns T if the argument is a printing character (space through ~ in ASCII), otherwise returns NIL." (and (typep char 'base-char) (< 31 (char-code (the base-char char)) 127))) (defun alpha-char-p (char) #!+sb-doc "The argument must be a character object. ALPHA-CHAR-P returns T if the argument is an alphabetic character, A-Z or a-z; otherwise NIL." (let ((m (char-code char))) (or (< 64 m 91) (< 96 m 123)))) (defun upper-case-p (char) #!+sb-doc "The argument must be a character object; UPPER-CASE-P returns T if the argument is an upper-case character, NIL otherwise." (< 64 (char-code char) 91)) (defun lower-case-p (char) #!+sb-doc "The argument must be a character object; LOWER-CASE-P returns T if the argument is a lower-case character, NIL otherwise." (< 96 (char-code char) 123)) (defun both-case-p (char) #!+sb-doc "The argument must be a character object. BOTH-CASE-P returns T if the argument is an alphabetic character and if the character exists in both upper and lower case. For ASCII, this is the same as ALPHA-CHAR-P." (let ((m (char-code char))) (or (< 64 m 91) (< 96 m 123)))) (defun digit-char-p (char &optional (radix 10.)) #!+sb-doc "If char is a digit in the specified radix, returns the fixnum for which that digit stands, else returns NIL." (let ((m (- (char-code char) 48))) (declare (fixnum m)) (cond ((<= radix 10.) ;; Special-case decimal and smaller radices. (if (and (>= m 0) (< m radix)) m nil)) ;; Digits 0 - 9 are used as is, since radix is larger. ((and (>= m 0) (< m 10)) m) ;; Check for upper case A - Z. ((and (>= (setq m (- m 7)) 10) (< m radix)) m) ;; Also check lower case a - z. ((and (>= (setq m (- m 32)) 10) (< m radix)) m) ;; Else, fail. (t nil)))) (defun alphanumericp (char) #!+sb-doc "Given a character-object argument, ALPHANUMERICP returns T if the argument is either numeric or alphabetic." (let ((m (char-code char))) (or (< 47 m 58) (< 64 m 91) (< 96 m 123)))) (defun char= (character &rest more-characters) #!+sb-doc "Return T if all of the arguments are the same character." (dolist (c more-characters t) (declare (type character c)) (unless (eq c character) (return nil)))) (defun char/= (character &rest more-characters) #!+sb-doc "Return T if no two of the arguments are the same character." (do* ((head character (car list)) (list more-characters (cdr list))) ((null list) t) (declare (type character head)) (dolist (c list) (declare (type character c)) (when (eq head c) (return-from char/= nil))))) (defun char< (character &rest more-characters) #!+sb-doc "Return T if the arguments are in strictly increasing alphabetic order." (do* ((c character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (< (char-int c) (char-int (car list))) (return nil)))) (defun char> (character &rest more-characters) #!+sb-doc "Return T if the arguments are in strictly decreasing alphabetic order." (do* ((c character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (> (char-int c) (char-int (car list))) (return nil)))) (defun char<= (character &rest more-characters) #!+sb-doc "Return T if the arguments are in strictly non-decreasing alphabetic order." (do* ((c character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (<= (char-int c) (char-int (car list))) (return nil)))) (defun char>= (character &rest more-characters) #!+sb-doc "Return T if the arguments are in strictly non-increasing alphabetic order." (do* ((c character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (>= (char-int c) (char-int (car list))) (return nil)))) ;;; EQUAL-CHAR-CODE is used by the following functions as a version of CHAR-INT ;;; which loses font, bits, and case info. (defmacro equal-char-code (character) `(let ((ch (char-code ,character))) (if (< 96 ch 123) (- ch 32) ch))) (defun char-equal (character &rest more-characters) #!+sb-doc "Return T if all of the arguments are the same character. Font, bits, and case are ignored." (do ((clist more-characters (cdr clist))) ((null clist) t) (unless (= (equal-char-code (car clist)) (equal-char-code character)) (return nil)))) (defun char-not-equal (character &rest more-characters) #!+sb-doc "Return T if no two of the arguments are the same character. Font, bits, and case are ignored." (do* ((head character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (do* ((l list (cdr l))) ((null l) t) (if (= (equal-char-code head) (equal-char-code (car l))) (return nil))) (return nil)))) (defun char-lessp (character &rest more-characters) #!+sb-doc "Return T if the arguments are in strictly increasing alphabetic order. Font, bits, and case are ignored." (do* ((c character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (< (equal-char-code c) (equal-char-code (car list))) (return nil)))) (defun char-greaterp (character &rest more-characters) #!+sb-doc "Return T if the arguments are in strictly decreasing alphabetic order. Font, bits, and case are ignored." (do* ((c character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (> (equal-char-code c) (equal-char-code (car list))) (return nil)))) (defun char-not-greaterp (character &rest more-characters) #!+sb-doc "Return T if the arguments are in strictly non-decreasing alphabetic order. Font, bits, and case are ignored." (do* ((c character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (<= (equal-char-code c) (equal-char-code (car list))) (return nil)))) (defun char-not-lessp (character &rest more-characters) #!+sb-doc "Return T if the arguments are in strictly non-increasing alphabetic order. Font, bits, and case are ignored." (do* ((c character (car list)) (list more-characters (cdr list))) ((null list) t) (unless (>= (equal-char-code c) (equal-char-code (car list))) (return nil)))) ;;;; miscellaneous functions (defun char-upcase (char) #!+sb-doc "Return CHAR converted to upper-case if that is possible." (if (lower-case-p char) (code-char (- (char-code char) 32)) char)) (defun char-downcase (char) #!+sb-doc "Return CHAR converted to lower-case if that is possible." (if (upper-case-p char) (code-char (+ (char-code char) 32)) char)) (defun digit-char (weight &optional (radix 10)) #!+sb-doc "All arguments must be integers. Returns a character object that represents a digit of the given weight in the specified radix. Returns NIL if no such character exists." (and (typep weight 'fixnum) (>= weight 0) (< weight radix) (< weight 36) (code-char (if (< weight 10) (+ 48 weight) (+ 55 weight)))))