src/code/target-char.lisp

   1 ;;;; character functions
   2 ;;;;
   3 ;;;; This implementation assumes the use of ASCII codes and the
   4 ;;;; specific character formats used in SBCL (and its ancestor, CMU
   5 ;;;; CL). It is optimized for performance rather than for portability
   6 ;;;; and elegance, and may have to be rewritten if the character
   7 ;;;; representation is changed.
   8 ;;;;
   9 ;;;; KLUDGE: As of sbcl-0.6.11.25, at least, the ASCII-dependence is
  10 ;;;; not confined to this file. E.g. there are DEFTRANSFORMs in
  11 ;;;; srctran.lisp for CHAR-UPCASE, CHAR-EQUAL, and CHAR-DOWNCASE, and
  12 ;;;; they assume ASCII. -- WHN 2001-03-25
  13
  14 ;;;; This software is part of the SBCL system. See the README file for
  15 ;;;; more information.
  16 ;;;;
  17 ;;;; This software is derived from the CMU CL system, which was
  18 ;;;; written at Carnegie Mellon University and released into the
  19 ;;;; public domain. The software is in the public domain and is
  20 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  21 ;;;; files for more information.
  22
  23 (in-package "SB!IMPL")
  24
  25 ;;; We compile some trivial character operations via inline expansion.
  26 #!-sb-fluid
  27 (declaim (inline standard-char-p graphic-char-p alpha-char-p
  28                  upper-case-p lower-case-p both-case-p alphanumericp
  29                  char-int))
  30 (declaim (maybe-inline digit-char-p digit-weight))
  31
  32 (deftype char-code ()
  33   `(integer 0 (,char-code-limit)))
  34
  35 (defvar *character-database*)
  36 (declaim (type (simple-array (unsigned-byte 8) (*)) *character-database*))
  37
  38 #!+sb-unicode
  39 (progn
  40  (defvar *unicode-character-name-database*)
  41  (defvar *unicode-character-name-huffman-tree*))
  42
  43 (macrolet ((frob ()
  44              (flet ((file (name type)
  45                       (merge-pathnames (make-pathname
  46                                         :directory
  47                                         '(:relative :up :up "output")
  48                                         :name name :type type)
  49                                        sb!xc:*compile-file-truename*)))
  50                `(progn
  51                   ,(with-open-file (stream (file "ucd" "dat")
  52                                            :direction :input
  53                                            :element-type '(unsigned-byte 8))
  54                      (let* ((length (file-length stream))
  55                             (array (make-array
  56                                     length :element-type '(unsigned-byte 8))))
  57                        (read-sequence array stream)
  58                        `(defun !character-database-cold-init ()
  59                           (setq *character-database* ',array))))
  60                   ,(with-open-file (stream (file "ucd-names" "lisp-expr")
  61                                            :direction :input
  62                                            :element-type 'character)
  63                      (let ((names (make-hash-table)))
  64                        #!+sb-unicode
  65                        (loop
  66                           for code-point = (read stream nil nil)
  67                           for char-name = (string-upcase (read stream nil nil))
  68                           while code-point
  69                           do (setf (gethash code-point names) char-name))
  70                        (let ((tree
  71                               #!+sb-unicode
  72                                (make-huffman-tree
  73                                 (let (list)
  74                                       (maphash (lambda (code name)
  75                                                  (declare (ignore code))
  76                                                  (push name list))
  77                                                names)
  78                                       list)))
  79                              (code->name
  80                               (make-array (hash-table-count names)
  81                                           :fill-pointer 0))
  82                              (name->code nil))
  83                          (maphash (lambda (code name)
  84                                     (vector-push
  85                                      (cons code (huffman-encode name tree))
  86                                      code->name))
  87                                    names)
  88                          (setf name->code
  89                                (sort (copy-seq code->name) #'< :key #'cdr))
  90                          (setf code->name
  91                                (sort (copy-seq name->code) #'< :key #'car))
  92                          (setf names nil)
  93                          `(defun !character-name-database-cold-init ()
  94                             #!+sb-unicode
  95                             (setq *unicode-character-name-database*
  96                                   (cons ',code->name ',name->code)
  97                                   *unicode-character-name-huffman-tree* ',tree)))))))))
  98   (frob))
  99 #+sb-xc-host (!character-database-cold-init)
 100 #+sb-xc-host (!character-name-database-cold-init)
 101
 102 (defparameter *base-char-name-alist*
 103   ;; Note: The *** markers here indicate character names which are
 104   ;; required by the ANSI specification of #'CHAR-NAME. For the others,
 105   ;; we prefer the ASCII standard name.
 106   '((#x00 "Nul" "Null" "^@")
 107     (#x01 "Soh" "^a")
 108     (#x02 "Stx" "^b")
 109     (#x03 "Etx" "^c")
 110     (#x04 "Eot" "^d")
 111     (#x05 "Enq" "^e")
 112     (#x06 "Ack" "^f")
 113     (#x07 "Bel" "Bell" "^g")
 114     (#x08 "Backspace" "^h" "Bs") ; *** See Note above
 115     (#x09 "Tab" "^i" "Ht") ; *** See Note above
 116     (#x0A "Newline" "Linefeed" "^j" "Lf" "Nl") ; *** See Note above
 117     (#x0B "Vt" "^k")
 118     (#x0C "Page" "^l" "Form" "Formfeed" "Ff" "Np") ; *** See Note above
 119     (#x0D "Return" "^m" "Cr") ; *** See Note above
 120     (#x0E "So" "^n")
 121     (#x0F "Si" "^o")
 122     (#x10 "Dle" "^p")
 123     (#x11 "Dc1" "^q")
 124     (#x12 "Dc2" "^r")
 125     (#x13 "Dc3" "^s")
 126     (#x14 "Dc4" "^t")
 127     (#x15 "Nak" "^u")
 128     (#x16 "Syn" "^v")
 129     (#x17 "Etb" "^w")
 130     (#x18 "Can" "^x")
 131     (#x19 "Em" "^y")
 132     (#x1A "Sub" "^z")
 133     (#x1B "Esc" "Escape" "^[" "Altmode" "Alt")
 134     (#x1C "Fs" "^\\")
 135     (#x1D "Gs" "^]")
 136     (#x1E "Rs" "^^")
 137     (#x1F "Us" "^_")
 138     (#x20 "Space" "Sp") ; *** See Note above
 139     (#x7f "Rubout" "Delete" "Del")
 140     (#x80 "C80")
 141     (#x81 "C81")
 142     (#x82 "Break-Permitted")
 143     (#x83 "No-Break-Permitted")
 144     (#x84 "C84")
 145     (#x85 "Next-Line")
 146     (#x86 "Start-Selected-Area")
 147     (#x87 "End-Selected-Area")
 148     (#x88 "Character-Tabulation-Set")
 149     (#x89 "Character-Tabulation-With-Justification")
 150     (#x8A "Line-Tabulation-Set")
 151     (#x8B "Partial-Line-Forward")
 152     (#x8C "Partial-Line-Backward")
 153     (#x8D "Reverse-Linefeed")
 154     (#x8E "Single-Shift-Two")
 155     (#x8F "Single-Shift-Three")
 156     (#x90 "Device-Control-String")
 157     (#x91 "Private-Use-One")
 158     (#x92 "Private-Use-Two")
 159     (#x93 "Set-Transmit-State")
 160     (#x94 "Cancel-Character")
 161     (#x95 "Message-Waiting")
 162     (#x96 "Start-Guarded-Area")
 163     (#x97 "End-Guarded-Area")
 164     (#x98 "Start-String")
 165     (#x99 "C99")
 166     (#x9A "Single-Character-Introducer")
 167     (#x9B "Control-Sequence-Introducer")
 168     (#x9C "String-Terminator")
 169     (#x9D "Operating-System-Command")
 170     (#x9E "Privacy-Message")
 171     (#x9F "Application-Program-Command"))) ; *** See Note above
 172 \f
 173 ;;;; accessor functions
 174
 175 ;; (* 8 186) => 1488
 176 ;; (+ 1488 (ash #x110000 -8)) => 5840
 177 (defun ucd-index (char)
 178   (let* ((cp (char-code char))
 179          (cp-high (ash cp -8))
 180          (page (aref *character-database* (+ 1488 cp-high))))
 181     (+ 5840 (ash page 10) (ash (ldb (byte 8 0) cp) 2))))
 182
 183 (defun ucd-value-0 (char)
 184   (aref *character-database* (ucd-index char)))
 185
 186 (defun ucd-value-1 (char)
 187   (let ((index (ucd-index char)))
 188     (dpb (aref *character-database* (+ index 3))
 189          (byte 8 16)
 190          (dpb (aref *character-database* (+ index 2))
 191               (byte 8 8)
 192               (aref *character-database* (1+ index))))))
 193
 194 (defun ucd-general-category (char)
 195   (aref *character-database* (* 8 (ucd-value-0 char))))
 196
 197 (defun ucd-decimal-digit (char)
 198   (let ((decimal-digit (aref *character-database*
 199                              (+ 3 (* 8 (ucd-value-0 char))))))
 200     (when (< decimal-digit 10)
 201       decimal-digit)))
 202
 203 (defun char-code (char)
 204   #!+sb-doc
 205   "Return the integer code of CHAR."
 206   ;; FIXME: do we actually need this?
 207   (etypecase char
 208     (character (char-code (truly-the character char)))))
 209
 210 (defun char-int (char)
 211   #!+sb-doc
 212   "Return the integer code of CHAR. (In SBCL this is the same as CHAR-CODE, as
 213    there are no character bits or fonts.)"
 214   (char-code char))
 215
 216 (defun code-char (code)
 217   #!+sb-doc
 218   "Return the character with the code CODE."
 219   (code-char code))
 220
 221 (defun character (object)
 222   #!+sb-doc
 223   "Coerce OBJECT into a CHARACTER if possible. Legal inputs are
 224   characters, strings and symbols of length 1."
 225   (flet ((do-error (control args)
 226            (error 'simple-type-error
 227                   :datum object
 228                   ;;?? how to express "symbol with name of length 1"?
 229                   :expected-type '(or character (string 1))
 230                   :format-control control
 231                   :format-arguments args)))
 232     (typecase object
 233       (character object)
 234       (string (if (= 1 (length (the string object)))
 235                   (char object 0)
 236                   (do-error
 237                    "String is not of length one: ~S" (list object))))
 238       (symbol (if (= 1 (length (symbol-name object)))
 239                   (schar (symbol-name object) 0)
 240                   (do-error
 241                    "Symbol name is not of length one: ~S" (list object))))
 242       (t (do-error "~S cannot be coerced to a character." (list object))))))
 243
 244 (defun char-name (char)
 245   #!+sb-doc
 246   "Return the name (a STRING) for a CHARACTER object."
 247   (let ((char-code (char-code char)))
 248     (or (second (assoc char-code *base-char-name-alist*))
 249         #!+sb-unicode
 250         (let ((h-code (cdr (binary-search char-code
 251                                           (car *unicode-character-name-database*)
 252                                           :key #'car))))
 253           (cond
 254             (h-code
 255              (huffman-decode h-code *unicode-character-name-huffman-tree*))
 256             ((< char-code #x10000)
 257              (format nil "U~4,'0X" char-code))
 258             (t
 259              (format nil "U~8,'0X" char-code)))))))
 260
 261 (defun name-char (name)
 262   #!+sb-doc
 263   "Given an argument acceptable to STRING, NAME-CHAR returns a character
 264   whose name is that string, if one exists. Otherwise, NIL is returned."
 265   (or (let ((char-code (car (rassoc-if (lambda (names)
 266                                          (member name names :test #'string-equal))
 267                                        *base-char-name-alist*))))
 268         (when char-code
 269           (code-char char-code)))
 270       #!+sb-unicode
 271       (let ((encoding (huffman-encode (string-upcase name)
 272                                        *unicode-character-name-huffman-tree*)))
 273         (when encoding
 274           (let* ((char-code
 275                   (car (binary-search encoding
 276                                       (cdr *unicode-character-name-database*)
 277                                       :key #'cdr)))
 278                  (name-string (string name))
 279                  (name-length (length name-string)))
 280             (cond
 281               (char-code
 282                (code-char char-code))
 283               ((and (or (= name-length 9)
 284                         (= name-length 5))
 285                     (char-equal (char name-string 0) #\U)
 286                     (loop for i from 1 below name-length
 287                           always (digit-char-p (char name-string i) 16)))
 288                (code-char (parse-integer name-string :start 1 :radix 16)))
 289               (t
 290                nil)))))))
 291 \f
 292 ;;;; predicates
 293
 294 (defun standard-char-p (char)
 295   #!+sb-doc
 296   "The argument must be a character object. STANDARD-CHAR-P returns T if the
 297    argument is a standard character -- one of the 95 ASCII printing characters
 298    or <return>."
 299   (and (typep char 'base-char)
 300        (let ((n (char-code (the base-char char))))
 301          (or (< 31 n 127)
 302              (= n 10)))))
 303
 304 (defun %standard-char-p (thing)
 305   #!+sb-doc
 306   "Return T if and only if THING is a standard-char. Differs from
 307   STANDARD-CHAR-P in that THING doesn't have to be a character."
 308   (and (characterp thing) (standard-char-p thing)))
 309
 310 (defun graphic-char-p (char)
 311   #!+sb-doc
 312   "The argument must be a character object. GRAPHIC-CHAR-P returns T if the
 313   argument is a printing character (space through ~ in ASCII), otherwise
 314   returns NIL."
 315   (let ((n (char-code char)))
 316     (or (< 31 n 127)
 317         (< 159 n))))
 318
 319 (defun alpha-char-p (char)
 320   #!+sb-doc
 321   "The argument must be a character object. ALPHA-CHAR-P returns T if the
 322    argument is an alphabetic character, A-Z or a-z; otherwise NIL."
 323   (< (ucd-general-category char) 5))
 324
 325 (defun upper-case-p (char)
 326   #!+sb-doc
 327   "The argument must be a character object; UPPER-CASE-P returns T if the
 328    argument is an upper-case character, NIL otherwise."
 329   (= (ucd-value-0 char) 0))
 330
 331 (defun lower-case-p (char)
 332   #!+sb-doc
 333   "The argument must be a character object; LOWER-CASE-P returns T if the
 334    argument is a lower-case character, NIL otherwise."
 335   (= (ucd-value-0 char) 1))
 336
 337 (defun both-case-p (char)
 338   #!+sb-doc
 339   "The argument must be a character object. BOTH-CASE-P returns T if the
 340   argument is an alphabetic character and if the character exists in
 341   both upper and lower case. For ASCII, this is the same as ALPHA-CHAR-P."
 342   (< (ucd-value-0 char) 2))
 343
 344 (defun digit-char-p (char &optional (radix 10.))
 345   #!+sb-doc
 346   "If char is a digit in the specified radix, returns the fixnum for
 347   which that digit stands, else returns NIL."
 348   (let ((m (- (char-code char) 48)))
 349     (declare (fixnum m))
 350     (cond ((<= radix 10.)
 351            ;; Special-case decimal and smaller radices.
 352            (if (and (>= m 0) (< m radix))  m  nil))
 353           ;; Digits 0 - 9 are used as is, since radix is larger.
 354           ((and (>= m 0) (< m 10)) m)
 355           ;; Check for upper case A - Z.
 356           ((and (>= (setq m (- m 7)) 10) (< m radix)) m)
 357           ;; Also check lower case a - z.
 358           ((and (>= (setq m (- m 32)) 10) (< m radix)) m)
 359           ;; Else, fail.
 360           (t (let ((number (ucd-decimal-digit char)))
 361                (when (and number (< number radix))
 362                  number))))))
 363
 364 (defun alphanumericp (char)
 365   #!+sb-doc
 366   "Given a character-object argument, ALPHANUMERICP returns T if the
 367    argument is either numeric or alphabetic."
 368   (let ((gc (ucd-general-category char)))
 369     (or (< gc 5)
 370         (= gc 12))))
 371
 372 (defun char= (character &rest more-characters)
 373   #!+sb-doc
 374   "Return T if all of the arguments are the same character."
 375   (declare (truly-dynamic-extent more-characters))
 376   (dolist (c more-characters t)
 377     (declare (type character c))
 378     (unless (eq c character) (return nil))))
 379
 380 (defun char/= (character &rest more-characters)
 381   #!+sb-doc
 382   "Return T if no two of the arguments are the same character."
 383   (declare (truly-dynamic-extent more-characters))
 384   (do* ((head character (car list))
 385         (list more-characters (cdr list)))
 386        ((null list) t)
 387     (declare (type character head))
 388     (dolist (c list)
 389       (declare (type character c))
 390       (when (eq head c) (return-from char/= nil)))))
 391
 392 (defun char< (character &rest more-characters)
 393   #!+sb-doc
 394   "Return T if the arguments are in strictly increasing alphabetic order."
 395   (declare (truly-dynamic-extent more-characters))
 396   (do* ((c character (car list))
 397         (list more-characters (cdr list)))
 398        ((null list) t)
 399     (unless (< (char-int c)
 400                (char-int (car list)))
 401       (return nil))))
 402
 403 (defun char> (character &rest more-characters)
 404   #!+sb-doc
 405   "Return T if the arguments are in strictly decreasing alphabetic order."
 406   (declare (truly-dynamic-extent more-characters))
 407   (do* ((c character (car list))
 408         (list more-characters (cdr list)))
 409        ((null list) t)
 410     (unless (> (char-int c)
 411                (char-int (car list)))
 412       (return nil))))
 413
 414 (defun char<= (character &rest more-characters)
 415   #!+sb-doc
 416   "Return T if the arguments are in strictly non-decreasing alphabetic order."
 417   (declare (truly-dynamic-extent more-characters))
 418   (do* ((c character (car list))
 419         (list more-characters (cdr list)))
 420        ((null list) t)
 421     (unless (<= (char-int c)
 422                 (char-int (car list)))
 423       (return nil))))
 424
 425 (defun char>= (character &rest more-characters)
 426   #!+sb-doc
 427   "Return T if the arguments are in strictly non-increasing alphabetic order."
 428   (declare (truly-dynamic-extent more-characters))
 429   (do* ((c character (car list))
 430         (list more-characters (cdr list)))
 431        ((null list) t)
 432     (unless (>= (char-int c)
 433                 (char-int (car list)))
 434       (return nil))))
 435
 436 ;;; EQUAL-CHAR-CODE is used by the following functions as a version of CHAR-INT
 437 ;;;  which loses font, bits, and case info.
 438
 439 (defmacro equal-char-code (character)
 440   (let ((ch (gensym)))
 441     `(let ((,ch ,character))
 442       (if (= (ucd-value-0 ,ch) 0)
 443           (ucd-value-1 ,ch)
 444           (char-code ,ch)))))
 445
 446 (defun two-arg-char-equal (c1 c2)
 447   (= (equal-char-code c1) (equal-char-code c2)))
 448
 449 (defun char-equal (character &rest more-characters)
 450   #!+sb-doc
 451   "Return T if all of the arguments are the same character.
 452   Font, bits, and case are ignored."
 453   (declare (truly-dynamic-extent more-characters))
 454   (do ((clist more-characters (cdr clist)))
 455       ((null clist) t)
 456     (unless (two-arg-char-equal (car clist) character)
 457       (return nil))))
 458
 459 (defun two-arg-char-not-equal (c1 c2)
 460   (/= (equal-char-code c1) (equal-char-code c2)))
 461
 462 (defun char-not-equal (character &rest more-characters)
 463   #!+sb-doc
 464   "Return T if no two of the arguments are the same character.
 465    Font, bits, and case are ignored."
 466   (declare (truly-dynamic-extent more-characters))
 467   (do* ((head character (car list))
 468         (list more-characters (cdr list)))
 469        ((null list) t)
 470     (unless (do* ((l list (cdr l)))
 471                  ((null l) t)
 472               (if (two-arg-char-equal head (car l))
 473                   (return nil)))
 474       (return nil))))
 475
 476 (defun two-arg-char-lessp (c1 c2)
 477   (< (equal-char-code c1) (equal-char-code c2)))
 478
 479 (defun char-lessp (character &rest more-characters)
 480   #!+sb-doc
 481   "Return T if the arguments are in strictly increasing alphabetic order.
 482    Font, bits, and case are ignored."
 483   (declare (truly-dynamic-extent more-characters))
 484   (do* ((c character (car list))
 485         (list more-characters (cdr list)))
 486        ((null list) t)
 487     (unless (two-arg-char-lessp c (car list))
 488       (return nil))))
 489
 490 (defun two-arg-char-greaterp (c1 c2)
 491   (> (equal-char-code c1) (equal-char-code c2)))
 492
 493 (defun char-greaterp (character &rest more-characters)
 494   #!+sb-doc
 495   "Return T if the arguments are in strictly decreasing alphabetic order.
 496    Font, bits, and case are ignored."
 497   (declare (truly-dynamic-extent more-characters))
 498   (do* ((c character (car list))
 499         (list more-characters (cdr list)))
 500        ((null list) t)
 501     (unless (two-arg-char-greaterp c (car list))
 502       (return nil))))
 503
 504 (defun two-arg-char-not-greaterp (c1 c2)
 505   (<= (equal-char-code c1) (equal-char-code c2)))
 506
 507 (defun char-not-greaterp (character &rest more-characters)
 508   #!+sb-doc
 509   "Return T if the arguments are in strictly non-decreasing alphabetic order.
 510    Font, bits, and case are ignored."
 511   (declare (truly-dynamic-extent more-characters))
 512   (do* ((c character (car list))
 513         (list more-characters (cdr list)))
 514        ((null list) t)
 515     (unless (two-arg-char-not-greaterp c (car list))
 516       (return nil))))
 517
 518 (defun two-arg-char-not-lessp (c1 c2)
 519   (>= (equal-char-code c1) (equal-char-code c2)))
 520
 521 (defun char-not-lessp (character &rest more-characters)
 522   #!+sb-doc
 523   "Return T if the arguments are in strictly non-increasing alphabetic order.
 524    Font, bits, and case are ignored."
 525   (declare (truly-dynamic-extent more-characters))
 526   (do* ((c character (car list))
 527         (list more-characters (cdr list)))
 528        ((null list) t)
 529     (unless (two-arg-char-not-lessp c (car list))
 530       (return nil))))
 531 \f
 532 ;;;; miscellaneous functions
 533
 534 (defun char-upcase (char)
 535   #!+sb-doc
 536   "Return CHAR converted to upper-case if that is possible.  Don't convert
 537    lowercase eszet (U+DF)."
 538   (if (= (ucd-value-0 char) 1)
 539       (code-char (ucd-value-1 char))
 540       char))
 541
 542 (defun char-downcase (char)
 543   #!+sb-doc
 544   "Return CHAR converted to lower-case if that is possible."
 545   (if (= (ucd-value-0 char) 0)
 546       (code-char (ucd-value-1 char))
 547       char))
 548
 549 (defun digit-char (weight &optional (radix 10))
 550   #!+sb-doc
 551   "All arguments must be integers. Returns a character object that
 552   represents a digit of the given weight in the specified radix. Returns
 553   NIL if no such character exists."
 554   (and (typep weight 'fixnum)
 555        (>= weight 0) (< weight radix) (< weight 36)
 556        (code-char (if (< weight 10) (+ 48 weight) (+ 55 weight)))))