ice-9/i18n.scm

   1 ;;;; i18n.scm --- internationalization support
   2
   3 ;;;;    Copyright (C) 2006, 2007 Free Software Foundation, Inc.
   4 ;;;;
   5 ;;;; This library is free software; you can redistribute it and/or
   6 ;;;; modify it under the terms of the GNU Lesser General Public
   7 ;;;; License as published by the Free Software Foundation; either
   8 ;;;; version 2.1 of the License, or (at your option) any later version.
   9 ;;;;
  10 ;;;; This library is distributed in the hope that it will be useful,
  11 ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 ;;;; Lesser General Public License for more details.
  14 ;;;;
  15 ;;;; You should have received a copy of the GNU Lesser General Public
  16 ;;;; License along with this library; if not, write to the Free Software
  17 ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18
  19 ;;; Author: Ludovic Courtès <ludovic.courtes@laas.fr>
  20
  21 ;;; Commentary:
  22 ;;;
  23 ;;; This module provides a number of routines that support
  24 ;;; internationalization (e.g., locale-dependent text collation, character
  25 ;;; mapping, etc.).  It also defines `locale' objects, representing locale
  26 ;;; settings, that may be passed around to most of these procedures.
  27 ;;;
  28
  29 ;;; Code:
  30
  31 (define-module (ice-9 i18n)
  32   :use-module (ice-9 optargs)
  33   :export (;; `locale' type
  34            make-locale locale?
  35            %global-locale
  36
  37            ;; text collation
  38            string-locale<? string-locale>?
  39            string-locale-ci<? string-locale-ci>? string-locale-ci=?
  40
  41            char-locale<? char-locale>?
  42            char-locale-ci<? char-locale-ci>? char-locale-ci=?
  43
  44            ;; character mapping
  45            char-locale-downcase char-locale-upcase
  46            string-locale-downcase string-locale-upcase
  47
  48            ;; reading numbers
  49            locale-string->integer locale-string->inexact
  50
  51            ;; charset/encoding
  52            locale-encoding
  53
  54            ;; days and months
  55            locale-day-short locale-day locale-month-short locale-month
  56
  57            ;; date and time
  58            locale-am-string locale-pm-string
  59            locale-date+time-format locale-date-format locale-time-format
  60            locale-time+am/pm-format
  61            locale-era locale-era-year
  62            locale-era-date-format locale-era-date+time-format
  63            locale-era-time-format
  64
  65            ;; monetary
  66            locale-currency-symbol
  67            locale-monetary-decimal-point locale-monetary-thousands-separator
  68            locale-monetary-grouping locale-monetary-fractional-digits
  69            locale-currency-symbol-precedes-positive?
  70            locale-currency-symbol-precedes-negative?
  71            locale-positive-separated-by-space?
  72            locale-negative-separated-by-space?
  73            locale-monetary-positive-sign locale-monetary-negative-sign
  74            locale-positive-sign-position locale-negative-sign-position
  75            monetary-amount->locale-string
  76
  77            ;; number formatting
  78            locale-digit-grouping locale-decimal-point
  79            locale-thousands-separator
  80            number->locale-string
  81
  82            ;; miscellaneous
  83            locale-yes-regexp locale-no-regexp))
  84
  85
  86 (load-extension "libguile-i18n-v-0" "scm_init_i18n")
  87
  88 \f
  89 ;;;
  90 ;;; Charset/encoding.
  91 ;;;
  92
  93 (define (locale-encoding . locale)
  94   (apply nl-langinfo CODESET locale))
  95
  96 \f
  97 ;;;
  98 ;;; Months and days.
  99 ;;;
 100
 101 ;; Helper macro: Define a procedure named NAME that maps its argument to
 102 ;; NL-ITEMS (when `nl-langinfo' is provided) or DEFAULTS (when `nl-langinfo'
 103 ;; is not provided).
 104 (define-macro (define-vector-langinfo-mapping name nl-items defaults)
 105   (let* ((item-count (length nl-items))
 106          (defines    (if (provided? 'nl-langinfo)
 107                          `(define %nl-items (vector #f ,@nl-items))
 108                          `(define %defaults (vector #f ,@defaults))))
 109          (make-body (lambda (result)
 110                       `(if (and (integer? item) (exact? item))
 111                            (if (and (>= item 1) (<= item ,item-count))
 112                                ,result
 113                                (throw 'out-of-range "out of range" item))
 114                            (throw 'wrong-type-arg "wrong argument type" item)))))
 115     `(define (,name item . locale)
 116        ,defines
 117        ,(make-body (if (provided? 'nl-langinfo)
 118                        '(apply nl-langinfo (vector-ref %nl-items item) locale)
 119                        '(vector-ref %defaults item))))))
 120
 121
 122 (define-vector-langinfo-mapping locale-day-short
 123   (ABDAY_1 ABDAY_2 ABDAY_3 ABDAY_4 ABDAY_5 ABDAY_6 ABDAY_7)
 124   ("Sun" "Mon" "Tue" "Wed" "Thu" "Fri" "Sat"))
 125
 126 (define-vector-langinfo-mapping locale-day
 127   (DAY_1 DAY_2 DAY_3 DAY_4 DAY_5 DAY_6 DAY_7)
 128   ("Sunday" "Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday"))
 129
 130 (define-vector-langinfo-mapping locale-month-short
 131   (ABMON_1 ABMON_2 ABMON_3 ABMON_4 ABMON_5 ABMON_6
 132    ABMON_7 ABMON_8 ABMON_9 ABMON_10 ABMON_11 ABMON_12)
 133   ("Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug" "Sep" "Oct" "Nov" "Dec"))
 134
 135 (define-vector-langinfo-mapping locale-month
 136   (MON_1 MON_2 MON_3 MON_4 MON_5 MON_6 MON_7 MON_8 MON_9 MON_10 MON_11 MON_12)
 137   ("January" "February" "March" "April" "May" "June" "July" "August"
 138    "September" "October" "November" "December"))
 139
 140
 141 \f
 142 ;;;
 143 ;;; Date and time.
 144 ;;;
 145
 146 ;; Helper macro: Define a procedure NAME that gets langinfo item ITEM.
 147 (define-macro (define-simple-langinfo-mapping name item default)
 148   (let ((body (if (and (provided? 'nl-langinfo) (defined? item))
 149                   `(apply nl-langinfo ,item locale)
 150                   default)))
 151     `(define (,name . locale)
 152        ,body)))
 153
 154 (define-simple-langinfo-mapping locale-am-string
 155   AM_STR "AM")
 156 (define-simple-langinfo-mapping locale-pm-string
 157   PM_STR "PM")
 158 (define-simple-langinfo-mapping locale-date+time-format
 159   D_T_FMT "%a %b %e %H:%M:%S %Y")
 160 (define-simple-langinfo-mapping locale-date-format
 161   D_FMT   "%m/%d/%y")
 162 (define-simple-langinfo-mapping locale-time-format
 163   T_FMT   "%H:%M:%S")
 164 (define-simple-langinfo-mapping locale-time+am/pm-format
 165   T_FMT_AMPM "%I:%M:%S %p")
 166 (define-simple-langinfo-mapping locale-era
 167   ERA        "")
 168 (define-simple-langinfo-mapping locale-era-year
 169   ERA_YEAR   "")
 170 (define-simple-langinfo-mapping locale-era-date+time-format
 171   ERA_D_T_FMT "")
 172 (define-simple-langinfo-mapping locale-era-date-format
 173   ERA_D_FMT   "")
 174 (define-simple-langinfo-mapping locale-era-time-format
 175   ERA_T_FMT   "")
 176
 177
 178 \f
 179 ;;;
 180 ;;; Monetary information.
 181 ;;;
 182
 183 (define-macro (define-monetary-langinfo-mapping name local-item intl-item
 184                                                 default/local default/intl)
 185   (let ((body
 186          (let ((intl  (if (and (provided? 'nl-langinfo) (defined? intl-item))
 187                           `(apply nl-langinfo ,intl-item locale)
 188                           default/intl))
 189                (local (if (and (provided? 'nl-langinfo) (defined? local-item))
 190                           `(apply nl-langinfo ,local-item locale)
 191                           default/local)))
 192            `(if intl? ,intl ,local))))
 193
 194     `(define (,name intl? . locale)
 195        ,body)))
 196
 197 ;; FIXME: How can we use ALT_DIGITS?
 198 (define-monetary-langinfo-mapping locale-currency-symbol
 199   CRNCYSTR           INT_CURR_SYMBOL
 200   "-"                "")
 201 (define-monetary-langinfo-mapping locale-monetary-fractional-digits
 202   FRAC_DIGITS        INT_FRAC_DIGITS
 203   2                  2)
 204
 205 (define-simple-langinfo-mapping locale-monetary-positive-sign
 206   POSITIVE_SIGN        "+")
 207 (define-simple-langinfo-mapping locale-monetary-negative-sign
 208   NEGATIVE_SIGN        "-")
 209 (define-simple-langinfo-mapping locale-monetary-decimal-point
 210   MON_DECIMAL_POINT    "")
 211 (define-simple-langinfo-mapping locale-monetary-thousands-separator
 212   MON_THOUSANDS_SEP    "")
 213 (define-simple-langinfo-mapping locale-monetary-digit-grouping
 214   MON_GROUPING         '())
 215
 216 (define-monetary-langinfo-mapping locale-currency-symbol-precedes-positive?
 217   P_CS_PRECEDES       INT_P_CS_PRECEDES
 218   #t                  #t)
 219 (define-monetary-langinfo-mapping locale-currency-symbol-precedes-negative?
 220   N_CS_PRECEDES       INT_N_CS_PRECEDES
 221   #t                  #t)
 222
 223
 224 (define-monetary-langinfo-mapping locale-positive-separated-by-space?
 225   ;; Whether a space should be inserted between a positive amount and the
 226   ;; currency symbol.
 227   P_SEP_BY_SPACE      INT_P_SEP_BY_SPACE
 228   #t                  #t)
 229 (define-monetary-langinfo-mapping locale-negative-separated-by-space?
 230   ;; Whether a space should be inserted between a negative amount and the
 231   ;; currency symbol.
 232   N_SEP_BY_SPACE      INT_N_SEP_BY_SPACE
 233   #t                  #t)
 234
 235 (define-monetary-langinfo-mapping locale-positive-sign-position
 236   ;; Position of the positive sign wrt. currency symbol and quantity in a
 237   ;; monetary amount.
 238   P_SIGN_POSN         INT_P_SIGN_POSN
 239   'unspecified        'unspecified)
 240 (define-monetary-langinfo-mapping locale-negative-sign-position
 241   ;; Position of the negative sign wrt. currency symbol and quantity in a
 242   ;; monetary amount.
 243   N_SIGN_POSN         INT_N_SIGN_POSN
 244   'unspecified        'unspecified)
 245
 246
 247 (define (%number-integer-part int grouping separator)
 248   ;; Process INT (a string denoting a number's integer part) and return a new
 249   ;; string with digit grouping and separators according to GROUPING (a list,
 250   ;; potentially circular) and SEPARATOR (a string).
 251
 252   ;; Process INT from right to left.
 253   (let loop ((int      int)
 254              (grouping grouping)
 255              (result   '()))
 256     (cond ((string=? int "") (apply string-append result))
 257           ((null? grouping)  (apply string-append int result))
 258           (else
 259            (let* ((len (string-length int))
 260                   (cut (min (car grouping) len)))
 261              (loop (substring int 0 (- len cut))
 262                    (cdr grouping)
 263                    (let ((sub (substring int (- len cut) len)))
 264                      (if (> len cut)
 265                          (cons* separator sub result)
 266                          (cons sub result)))))))))
 267
 268 (define (add-monetary-sign+currency amount figure intl? locale)
 269   ;; Add a sign and currency symbol around FIGURE.  FIGURE should be a
 270   ;; formatted unsigned amount (a string) representing AMOUNT.
 271   (let* ((positive? (> amount 0))
 272          (sign
 273           (cond ((> amount 0) (locale-monetary-positive-sign locale))
 274                 ((< amount 0) (locale-monetary-negative-sign locale))
 275                 (else         "")))
 276          (currency (locale-currency-symbol intl? locale))
 277          (currency-precedes?
 278           (if positive?
 279               locale-currency-symbol-precedes-positive?
 280               locale-currency-symbol-precedes-negative?))
 281          (separated?
 282           (if positive?
 283               locale-positive-separated-by-space?
 284               locale-negative-separated-by-space?))
 285          (sign-position
 286           (if positive?
 287               locale-positive-sign-position
 288               locale-negative-sign-position))
 289          (currency-space
 290           (if (separated? intl? locale) " " ""))
 291          (append-currency
 292           (lambda (amt)
 293             (if (currency-precedes? intl? locale)
 294                 (string-append currency currency-space amt)
 295                 (string-append amt currency-space currency)))))
 296
 297     (case (sign-position intl? locale)
 298       ((parenthesize)
 299        (string-append "(" (append-currency figure) ")"))
 300       ((sign-before)
 301        (string-append sign (append-currency figure)))
 302       ((sign-after unspecified)
 303        ;; following glibc's recommendation for `unspecified'.
 304        (if (currency-precedes? intl? locale)
 305            (string-append currency currency-space sign figure)
 306            (string-append figure currency-space currency sign)))
 307       ((sign-before-currency-symbol)
 308        (if (currency-precedes? intl? locale)
 309            (string-append sign currency currency-space figure)
 310            (string-append figure currency-space sign currency))) ;; unlikely
 311       ((sign-after-currency-symbol)
 312        (if (currency-precedes? intl? locale)
 313            (string-append currency sign currency-space figure)
 314            (string-append figure currency-space currency sign)))
 315       (else
 316        (error "unsupported sign position" (sign-position intl? locale))))))
 317
 318
 319 (define* (monetary-amount->locale-string amount intl?
 320                                          #:optional (locale %global-locale))
 321   "Convert @var{amount} (an inexact) into a string according to the cultural
 322 conventions of either @var{locale} (a locale object) or the current locale.
 323 If @var{intl?} is true, then the international monetary format for the given
 324 locale is used."
 325
 326   (let* ((fraction-digits
 327           (or (locale-monetary-fractional-digits intl? locale) 2))
 328          (decimal-part
 329           (lambda (dec)
 330             (if (or (string=? dec "") (eq? 0 fraction-digits))
 331                 ""
 332                 (string-append (locale-monetary-decimal-point locale)
 333                                (if (< fraction-digits (string-length dec))
 334                                    (substring dec 0 fraction-digits)
 335                                    dec)))))
 336
 337          (external-repr (number->string (if (> amount 0) amount (- amount))))
 338          (int+dec   (string-split external-repr #\.))
 339          (int       (car int+dec))
 340          (dec       (decimal-part (if (null? (cdr int+dec))
 341                                       ""
 342                                       (cadr int+dec))))
 343          (grouping  (locale-monetary-digit-grouping locale))
 344          (separator (locale-monetary-thousands-separator locale)))
 345
 346       (add-monetary-sign+currency amount
 347                                   (string-append
 348                                    (%number-integer-part int grouping
 349                                                          separator)
 350                                    dec)
 351                                   intl? locale)))
 352
 353
 354 \f
 355 ;;;
 356 ;;; Number formatting.
 357 ;;;
 358
 359 (define-simple-langinfo-mapping locale-digit-grouping
 360   GROUPING             '())
 361 (define-simple-langinfo-mapping locale-decimal-point
 362   RADIXCHAR            ".")
 363 (define-simple-langinfo-mapping locale-thousands-separator
 364   THOUSEP              "")
 365
 366 (define* (number->locale-string number
 367                                 #:optional (fraction-digits #t)
 368                                            (locale %global-locale))
 369   "Convert @var{number} (an inexact) into a string according to the cultural
 370 conventions of either @var{locale} (a locale object) or the current locale.
 371 Optionally, @var{fraction-digits} may be bound to an integer specifying the
 372 number of fractional digits to be displayed."
 373
 374   (let* ((sign
 375           (cond ((> number 0) "")
 376                 ((< number 0) "-")
 377                 (else         "")))
 378          (decimal-part
 379           (lambda (dec)
 380             (if (or (string=? dec "") (eq? 0 fraction-digits))
 381                 ""
 382                 (string-append (locale-decimal-point locale)
 383                                (if (and (integer? fraction-digits)
 384                                         (< fraction-digits
 385                                            (string-length dec)))
 386                                    (substring dec 0 fraction-digits)
 387                                    dec))))))
 388
 389     (let* ((external-repr (number->string (if (> number 0)
 390                                               number
 391                                               (- number))))
 392            (int+dec   (string-split external-repr #\.))
 393            (int       (car int+dec))
 394            (dec       (decimal-part (if (null? (cdr int+dec))
 395                                         ""
 396                                         (cadr int+dec))))
 397            (grouping  (locale-digit-grouping locale))
 398            (separator (locale-thousands-separator locale)))
 399
 400       (string-append sign
 401                      (%number-integer-part int grouping separator)
 402                      dec))))
 403
 404 \f
 405 ;;;
 406 ;;; Miscellaneous.
 407 ;;;
 408
 409 (define-simple-langinfo-mapping locale-yes-regexp
 410   YESEXPR              "^[yY]")
 411 (define-simple-langinfo-mapping locale-no-regexp
 412   NOEXPR               "^[nN]")
 413
 414 ;; `YESSTR' and `NOSTR' are considered deprecated so we don't provide them.
 415
 416
 417 ;;; Local Variables:
 418 ;;; coding: latin-1
 419 ;;; End:
 420
 421 ;;; i18n.scm ends here