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@c -*-texinfo-*- |
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@c This is part of the GNU Guile Reference Manual. |
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@c Copyright (C) 1996, 1997, 2000, 2001, 2002, 2003, 2004, 2006, 2007, |
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@c 2009, 2010, 2017 Free Software Foundation, Inc. |
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@c See the file guile.texi for copying conditions. |
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@node Internationalization |
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@section Support for Internationalization |
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@cindex internationalization |
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@cindex i18n |
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Guile provides internationalization@footnote{For concision and style, |
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programmers often like to refer to internationalization as ``i18n''.} |
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support for Scheme programs in two ways. First, procedures to |
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manipulate text and data in a way that conforms to particular cultural |
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conventions (i.e., in a ``locale-dependent'' way) are provided in the |
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@code{(ice-9 i18n)}. Second, Guile allows the use of GNU |
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@code{gettext} to translate program message strings. |
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@menu |
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* i18n Introduction:: Introduction to Guile's i18n support. |
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* Text Collation:: Sorting strings and characters. |
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* Character Case Mapping:: Case mapping. |
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* Number Input and Output:: Parsing and printing numbers. |
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* Accessing Locale Information:: Detailed locale information. |
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* Gettext Support:: Translating message strings. |
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@end menu |
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@node i18n Introduction, Text Collation, Internationalization, Internationalization |
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@subsection Internationalization with Guile |
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In order to make use of the functions described thereafter, the |
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@code{(ice-9 i18n)} module must be imported in the usual way: |
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@example |
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(use-modules (ice-9 i18n)) |
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@end example |
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@cindex cultural conventions |
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The @code{(ice-9 i18n)} module provides procedures to manipulate text |
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and other data in a way that conforms to the cultural conventions |
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chosen by the user. Each region of the world or language has its own |
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customs to, for instance, represent real numbers, classify characters, |
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collate text, etc. All these aspects comprise the so-called |
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``cultural conventions'' of that region or language. |
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@cindex locale |
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@cindex locale category |
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Computer systems typically refer to a set of cultural conventions as a |
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@dfn{locale}. For each particular aspect that comprise those cultural |
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conventions, a @dfn{locale category} is defined. For instance, the |
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way characters are classified is defined by the @code{LC_CTYPE} |
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category, while the language in which program messages are issued to |
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the user is defined by the @code{LC_MESSAGES} category |
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(@pxref{Locales, General Locale Information} for details). |
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@cindex locale object |
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The procedures provided by this module allow the development of |
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programs that adapt automatically to any locale setting. As we will |
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see later, many of these procedures can optionally take a @dfn{locale |
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object} argument. This additional argument defines the locale |
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settings that must be followed by the invoked procedure. When it is |
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omitted, then the current locale settings of the process are followed |
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(@pxref{Locales, @code{setlocale}}). |
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The following procedures allow the manipulation of such locale |
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objects. |
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@deffn {Scheme Procedure} make-locale category-list locale-name [base-locale] |
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@deffnx {C Function} scm_make_locale (category_list, locale_name, base_locale) |
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Return a reference to a data structure representing a set of locale |
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datasets. @var{locale-name} should be a string denoting a particular |
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locale (e.g., @code{"aa_DJ"}) and @var{category-list} should be either |
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a list of locale categories or a single category as used with |
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@code{setlocale} (@pxref{Locales, @code{setlocale}}). Optionally, if |
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@code{base-locale} is passed, it should be a locale object denoting |
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settings for categories not listed in @var{category-list}. |
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The following invocation creates a locale object that combines the use |
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of Swedish for messages and character classification with the |
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default settings for the other categories (i.e., the settings of the |
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default @code{C} locale which usually represents conventions in use in |
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the USA): |
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@example |
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(make-locale (list LC_MESSAGES LC_CTYPE) "sv_SE") |
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@end example |
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The following example combines the use of Esperanto messages and |
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conventions with monetary conventions from Croatia: |
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@example |
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(make-locale LC_MONETARY "hr_HR" |
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(make-locale LC_ALL "eo_EO")) |
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@end example |
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A @code{system-error} exception (@pxref{Handling Errors}) is raised by |
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@code{make-locale} when @var{locale-name} does not match any of the |
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locales compiled on the system. Note that on non-GNU systems, this |
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error may be raised later, when the locale object is actually used. |
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@end deffn |
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@deffn {Scheme Procedure} locale? obj |
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@deffnx {C Function} scm_locale_p (obj) |
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Return true if @var{obj} is a locale object. |
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@end deffn |
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@defvr {Scheme Variable} %global-locale |
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@defvrx {C Variable} scm_global_locale |
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This variable is bound to a locale object denoting the current process |
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locale as installed using @code{setlocale ()} (@pxref{Locales}). It |
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may be used like any other locale object, including as a third |
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argument to @code{make-locale}, for instance. |
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@end defvr |
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@node Text Collation, Character Case Mapping, i18n Introduction, Internationalization |
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@subsection Text Collation |
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The following procedures provide support for text collation, i.e., |
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locale-dependent string and character sorting. |
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@deffn {Scheme Procedure} string-locale<? s1 s2 [locale] |
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@deffnx {C Function} scm_string_locale_lt (s1, s2, locale) |
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@deffnx {Scheme Procedure} string-locale>? s1 s2 [locale] |
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@deffnx {C Function} scm_string_locale_gt (s1, s2, locale) |
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@deffnx {Scheme Procedure} string-locale-ci<? s1 s2 [locale] |
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@deffnx {C Function} scm_string_locale_ci_lt (s1, s2, locale) |
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@deffnx {Scheme Procedure} string-locale-ci>? s1 s2 [locale] |
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@deffnx {C Function} scm_string_locale_ci_gt (s1, s2, locale) |
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Compare strings @var{s1} and @var{s2} in a locale-dependent way. If |
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@var{locale} is provided, it should be locale object (as returned by |
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@code{make-locale}) and will be used to perform the comparison |
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otherwise, the current system locale is used. For the @code{-ci} |
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variants, the comparison is made in a case-insensitive way. |
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@end deffn |
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@deffn {Scheme Procedure} string-locale-ci=? s1 s2 [locale] |
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@deffnx {C Function} scm_string_locale_ci_eq (s1, s2, locale) |
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Compare strings @var{s1} and @var{s2} in a case-insensitive, and |
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locale-dependent way. If @var{locale} is provided, it should be |
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a locale object (as returned by @code{make-locale}) and will be used to |
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perform the comparison |
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@end deffn |
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@deffn {Scheme Procedure} char-locale<? c1 c2 [locale] |
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@deffnx {C Function} scm_char_locale_lt (c1, c2, locale) |
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@deffnx {Scheme Procedure} char-locale>? c1 c2 [locale] |
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@deffnx {C Function} scm_char_locale_gt (c1, c2, locale) |
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@deffnx {Scheme Procedure} char-locale-ci<? c1 c2 [locale] |
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@deffnx {C Function} scm_char_locale_ci_lt (c1, c2, locale) |
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@deffnx {Scheme Procedure} char-locale-ci>? c1 c2 [locale] |
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@deffnx {C Function} scm_char_locale_ci_gt (c1, c2, locale) |
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Compare characters @var{c1} and @var{c2} according to either |
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@var{locale} (a locale object as returned by @code{make-locale}) or |
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the current locale. For the @code{-ci} variants, the comparison is |
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made in a case-insensitive way. |
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@end deffn |
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@deffn {Scheme Procedure} char-locale-ci=? c1 c2 [locale] |
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@deffnx {C Function} scm_char_locale_ci_eq (c1, c2, locale) |
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Return true if character @var{c1} is equal to @var{c2}, in a case |
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insensitive way according to @var{locale} or to the current locale. |
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@end deffn |
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@node Character Case Mapping, Number Input and Output, Text Collation, Internationalization |
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@subsection Character Case Mapping |
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The procedures below provide support for ``character case mapping'', |
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i.e., to convert characters or strings to their upper-case or |
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lower-case equivalent. Note that SRFI-13 provides procedures that |
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look similar (@pxref{Alphabetic Case Mapping}). However, the SRFI-13 |
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procedures are locale-independent. Therefore, they do not take into |
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account specificities of the customs in use in a particular language |
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or region of the world. For instance, while most languages using the |
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Latin alphabet map lower-case letter ``i'' to upper-case letter ``I'', |
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Turkish maps lower-case ``i'' to ``Latin capital letter I with dot |
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above''. The following procedures allow programmers to provide |
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idiomatic character mapping. |
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@deffn {Scheme Procedure} char-locale-downcase chr [locale] |
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@deffnx {C Function} scm_char_locale_upcase (chr, locale) |
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Return the lowercase character that corresponds to @var{chr} according |
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to either @var{locale} or the current locale. |
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@end deffn |
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@deffn {Scheme Procedure} char-locale-upcase chr [locale] |
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@deffnx {C Function} scm_char_locale_downcase (chr, locale) |
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Return the uppercase character that corresponds to @var{chr} according |
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to either @var{locale} or the current locale. |
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@end deffn |
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@deffn {Scheme Procedure} char-locale-titlecase chr [locale] |
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@deffnx {C Function} scm_char_locale_titlecase (chr, locale) |
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Return the titlecase character that corresponds to @var{chr} according |
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to either @var{locale} or the current locale. |
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@end deffn |
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@deffn {Scheme Procedure} string-locale-upcase str [locale] |
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@deffnx {C Function} scm_string_locale_upcase (str, locale) |
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Return a new string that is the uppercase version of @var{str} |
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according to either @var{locale} or the current locale. |
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@end deffn |
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@deffn {Scheme Procedure} string-locale-downcase str [locale] |
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@deffnx {C Function} scm_string_locale_downcase (str, locale) |
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Return a new string that is the down-case version of @var{str} |
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according to either @var{locale} or the current locale. |
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@end deffn |
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@deffn {Scheme Procedure} string-locale-titlecase str [locale] |
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@deffnx {C Function} scm_string_locale_titlecase (str, locale) |
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Return a new string that is the titlecase version of @var{str} |
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according to either @var{locale} or the current locale. |
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@end deffn |
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@node Number Input and Output, Accessing Locale Information, Character Case Mapping, Internationalization |
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@subsection Number Input and Output |
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The following procedures allow programs to read and write numbers |
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written according to a particular locale. As an example, in English, |
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``ten thousand and a half'' is usually written @code{10,000.5} while |
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in French it is written @code{10 000,5}. These procedures allow such |
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differences to be taken into account. |
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@findex strtod |
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@deffn {Scheme Procedure} locale-string->integer str [base [locale]] |
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@deffnx {C Function} scm_locale_string_to_integer (str, base, locale) |
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Convert string @var{str} into an integer according to either |
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@var{locale} (a locale object as returned by @code{make-locale}) or |
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the current process locale. If @var{base} is specified, then it |
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determines the base of the integer being read (e.g., @code{16} for an |
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hexadecimal number, @code{10} for a decimal number) |
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decimal numbers are read. Return two values (@pxref{Multiple |
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Values}): an integer (on success) or @code{#f}, and the number of |
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characters read from @var{str} (@code{0} on failure). |
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This function is based on the C library's @code{strtol} function |
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(@pxref{Parsing of Integers, @code{strtol},, libc, The GNU C Library |
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Reference Manual}). |
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@end deffn |
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@findex strtod |
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@deffn {Scheme Procedure} locale-string->inexact str [locale] |
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@deffnx {C Function} scm_locale_string_to_inexact (str, locale) |
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Convert string @var{str} into an inexact number according to either |
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@var{locale} (a locale object as returned by @code{make-locale}) or |
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the current process locale. Return two values (@pxref{Multiple |
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Values}): an inexact number (on success) or @code{#f}, and the number |
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of characters read from @var{str} (@code{0} on failure). |
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This function is based on the C library's @code{strtod} function |
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(@pxref{Parsing of Floats, @code{strtod},, libc, The GNU C Library |
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Reference Manual}). |
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@end deffn |
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@deffn {Scheme Procedure} number->locale-string number [fraction-digits [locale]] |
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Convert @var{number} (an inexact) into a string according to the |
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cultural conventions of either @var{locale} (a locale object) or the |
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current locale. By default, print as many fractional digits as |
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necessary, up to an upper bound. Optionally, @var{fraction-digits} may |
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be bound to an integer specifying the number of fractional digits to be |
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displayed. |
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@end deffn |
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@deffn {Scheme Procedure} monetary-amount->locale-string amount intl? [locale] |
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Convert @var{amount} (an inexact denoting a monetary amount) into a |
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string according to the cultural conventions of either @var{locale} (a |
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locale object) or the current locale. If @var{intl?} is true, then |
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the international monetary format for the given locale is used |
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(@pxref{Currency Symbol, international and locale monetary formats,, |
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libc, The GNU C Library Reference Manual}). |
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@end deffn |
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@node Accessing Locale Information, Gettext Support, Number Input and Output, Internationalization |
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@subsection Accessing Locale Information |
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@findex nl_langinfo |
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@cindex low-level locale information |
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It is sometimes useful to obtain very specific information about a |
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locale such as the word it uses for days or months, its format for |
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representing floating-point figures, etc. The @code{(ice-9 i18n)} |
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module provides support for this in a way that is similar to the libc |
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functions @code{nl_langinfo ()} and @code{localeconv ()} |
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(@pxref{Locale Information, accessing locale information from C,, |
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libc, The GNU C Library Reference Manual}). The available functions |
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are listed below. |
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@deffn {Scheme Procedure} locale-encoding [locale] |
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Return the name of the encoding (a string whose interpretation is |
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system-dependent) of either @var{locale} or the current locale. |
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@end deffn |
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The following functions deal with dates and times. |
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@deffn {Scheme Procedure} locale-day day [locale] |
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@deffnx {Scheme Procedure} locale-day-short day [locale] |
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@deffnx {Scheme Procedure} locale-month month [locale] |
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@deffnx {Scheme Procedure} locale-month-short month [locale] |
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Return the word (a string) used in either @var{locale} or the current |
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locale to name the day (or month) denoted by @var{day} (or |
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@var{month}), an integer between 1 and 7 (or 1 and 12). The |
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@code{-short} variants provide an abbreviation instead of a full name. |
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@end deffn |
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@deffn {Scheme Procedure} locale-am-string [locale] |
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@deffnx {Scheme Procedure} locale-pm-string [locale] |
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Return a (potentially empty) string that is used to denote @i{ante |
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meridiem} (or @i{post meridiem}) hours in 12-hour format. |
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@end deffn |
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@deffn {Scheme Procedure} locale-date+time-format [locale] |
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@deffnx {Scheme Procedure} locale-date-format [locale] |
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@deffnx {Scheme Procedure} locale-time-format [locale] |
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@deffnx {Scheme Procedure} locale-time+am/pm-format [locale] |
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@deffnx {Scheme Procedure} locale-era-date-format [locale] |
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@deffnx {Scheme Procedure} locale-era-date+time-format [locale] |
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@deffnx {Scheme Procedure} locale-era-time-format [locale] |
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These procedures return format strings suitable to @code{strftime} |
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(@pxref{Time}) that may be used to display (part of) a date/time |
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according to certain constraints and to the conventions of either |
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@var{locale} or the current locale (@pxref{The Elegant and Fast Way, |
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the @code{nl_langinfo ()} items,, libc, The GNU C Library Reference |
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Manual}). |
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@end deffn |
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@deffn {Scheme Procedure} locale-era [locale] |
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@deffnx {Scheme Procedure} locale-era-year [locale] |
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These functions return, respectively, the era and the year of the |
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relevant era used in @var{locale} or the current locale. Most locales |
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do not define this value. In this case, the empty string is returned. |
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An example of a locale that does define this value is the Japanese |
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one. |
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@end deffn |
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The following procedures give information about number representation. |
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@deffn {Scheme Procedure} locale-decimal-point [locale] |
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@deffnx {Scheme Procedure} locale-thousands-separator [locale] |
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These functions return a string denoting the representation of the |
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decimal point or that of the thousand separator (respectively) for |
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either @var{locale} or the current locale. |
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@end deffn |
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@deffn {Scheme Procedure} locale-digit-grouping [locale] |
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Return a (potentially circular) list of integers denoting how digits |
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of the integer part of a number are to be grouped, starting at the |
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decimal point and going to the left. The list contains integers |
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indicating the size of the successive groups, from right to left. If |
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the list is non-circular, then no grouping occurs for digits beyond |
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the last group. |
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For instance, if the returned list is a circular list that contains |
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only @code{3} and the thousand separator is @code{","} (as is the case |
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with English locales), then the number @code{12345678} should be |
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printed @code{12,345,678}. |
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@end deffn |
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The following procedures deal with the representation of monetary |
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amounts. Some of them take an additional @var{intl?} argument (a |
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boolean) that tells whether the international or local monetary |
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conventions for the given locale are to be used. |
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@deffn {Scheme Procedure} locale-monetary-decimal-point [locale] |
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@deffnx {Scheme Procedure} locale-monetary-thousands-separator [locale] |
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@deffnx {Scheme Procedure} locale-monetary-grouping [locale] |
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These are the monetary counterparts of the above procedures. These |
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procedures apply to monetary amounts. |
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@end deffn |
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@deffn {Scheme Procedure} locale-currency-symbol intl? [locale] |
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Return the currency symbol (a string) of either @var{locale} or the |
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current locale. |
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The following example illustrates the difference between the local and |
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international monetary formats: |
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@example |
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(define us (make-locale LC_MONETARY "en_US")) |
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(locale-currency-symbol #f us) |
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@result{} "-$" |
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(locale-currency-symbol #t us) |
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@result{} "USD " |
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@end example |
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@end deffn |
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@deffn {Scheme Procedure} locale-monetary-fractional-digits intl? [locale] |
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Return the number of fractional digits to be used when printing |
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monetary amounts according to either @var{locale} or the current |
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locale. If the locale does not specify it, then @code{#f} is |
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returned. |
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@end deffn |
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@deffn {Scheme Procedure} locale-currency-symbol-precedes-positive? intl? [locale] |
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@deffnx {Scheme Procedure} locale-currency-symbol-precedes-negative? intl? [locale] |
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@deffnx {Scheme Procedure} locale-positive-separated-by-space? intl? [locale] |
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@deffnx {Scheme Procedure} locale-negative-separated-by-space? intl? [locale] |
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These procedures return a boolean indicating whether the currency |
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symbol should precede a positive/negative number, and whether a |
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whitespace should be inserted between the currency symbol and a |
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positive/negative amount. |
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@end deffn |
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@deffn {Scheme Procedure} locale-monetary-positive-sign [locale] |
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@deffnx {Scheme Procedure} locale-monetary-negative-sign [locale] |
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Return a string denoting the positive (respectively negative) sign |
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that should be used when printing a monetary amount. |
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@end deffn |
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@deffn {Scheme Procedure} locale-positive-sign-position |
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@deffnx {Scheme Procedure} locale-negative-sign-position |
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These functions return a symbol telling where a sign of a |
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positive/negative monetary amount is to appear when printing it. The |
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possible values are: |
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@table @code |
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@item parenthesize |
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The currency symbol and quantity should be surrounded by parentheses. |
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@item sign-before |
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Print the sign string before the quantity and currency symbol. |
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@item sign-after |
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Print the sign string after the quantity and currency symbol. |
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@item sign-before-currency-symbol |
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Print the sign string right before the currency symbol. |
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@item sign-after-currency-symbol |
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Print the sign string right after the currency symbol. |
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@item unspecified |
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Unspecified. We recommend you print the sign after the currency |
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symbol. |
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@end table |
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@end deffn |
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Finally, the two following procedures may be helpful when programming |
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user interfaces: |
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@deffn {Scheme Procedure} locale-yes-regexp [locale] |
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@deffnx {Scheme Procedure} locale-no-regexp [locale] |
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Return a string that can be used as a regular expression to recognize |
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a positive (respectively, negative) response to a yes/no question. |
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For the C locale, the default values are typically @code{"^[yY]"} and |
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@code{"^[nN]"}, respectively. |
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Here is an example: |
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@example |
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(use-modules (ice-9 rdelim)) |
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(format #t "Does Guile rock?~%") |
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(let lp ((answer (read-line))) |
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(cond ((string-match (locale-yes-regexp) answer) |
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(format #t "High fives!~%")) |
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((string-match (locale-no-regexp) answer) |
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(format #t "How about now? Does it rock yet?~%") |
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(lp (read-line))) |
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(else |
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(format #t "What do you mean?~%") |
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(lp (read-line))))) |
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@end example |
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For an internationalized yes/no string output, @code{gettext} should |
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be used (@pxref{Gettext Support}). |
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@end deffn |
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Example uses of some of these functions are the implementation of the |
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@code{number->locale-string} and @code{monetary-amount->locale-string} |
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procedures (@pxref{Number Input and Output}), as well as that the |
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SRFI-19 date and time conversion to/from strings (@pxref{SRFI-19}). |
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@node Gettext Support, , Accessing Locale Information, Internationalization |
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@subsection Gettext Support |
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Guile provides an interface to GNU @code{gettext} for translating |
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message strings (@pxref{Introduction,,, gettext, GNU @code{gettext} |
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utilities}). |
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Messages are collected in domains, so different libraries and programs |
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maintain different message catalogs. The @var{domain} parameter in |
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the functions below is a string (it becomes part of the message |
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catalog filename). |
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When @code{gettext} is not available, or if Guile was configured |
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@samp{--without-nls}, dummy functions doing no translation are |
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provided. When @code{gettext} support is available in Guile, the |
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@code{i18n} feature is provided (@pxref{Feature Tracking}). |
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@deffn {Scheme Procedure} gettext msg [domain [category]] |
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@deffnx {C Function} scm_gettext (msg, domain, category) |
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Return the translation of @var{msg} in @var{domain}. @var{domain} is |
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optional and defaults to the domain set through @code{textdomain} |
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below. @var{category} is optional and defaults to @code{LC_MESSAGES} |
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(@pxref{Locales}). |
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Normal usage is for @var{msg} to be a literal string. |
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@command{xgettext} can extract those from the source to form a message |
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catalog ready for translators (@pxref{xgettext Invocation,, Invoking |
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the @command{xgettext} Program, gettext, GNU @code{gettext} |
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utilities}). |
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@example |
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(display (gettext "You are in a maze of twisty passages.")) |
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@end example |
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It is conventional to use @code{G_} as a shorthand for |
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@code{gettext}.@footnote{Users of @code{gettext} might be a bit |
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surprised that @code{G_} is the conventional abbreviation for |
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@code{gettext}. In most other languages, the conventional shorthand is |
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@code{_}. Guile uses @code{G_} because @code{_} is already taken, as it |
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is bound to a syntactic keyword used by @code{syntax-rules}, |
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@code{match}, and other macros.} Libraries can define @code{G_} in such |
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a way to look up translations using its specific @var{domain}, allowing |
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different parts of a program to have different translation sources. |
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@example |
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(define (G_ msg) (gettext msg "mylibrary")) |
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(display (G_ "File not found.")) |
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@end example |
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@code{G_} is also a good place to perhaps strip disambiguating extra |
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text from the message string, as for instance in @ref{GUI program |
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problems,, How to use @code{gettext} in GUI programs, gettext, GNU |
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@code{gettext} utilities}. |
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@end deffn |
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@deffn {Scheme Procedure} ngettext msg msgplural n [domain [category]] |
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@deffnx {C Function} scm_ngettext (msg, msgplural, n, domain, category) |
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Return the translation of @var{msg}/@var{msgplural} in @var{domain}, |
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with a plural form chosen appropriately for the number @var{n}. |
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@var{domain} is optional and defaults to the domain set through |
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@code{textdomain} below. @var{category} is optional and defaults to |
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@code{LC_MESSAGES} (@pxref{Locales}). |
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@var{msg} is the singular form, and @var{msgplural} the plural. When |
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no translation is available, @var{msg} is used if @math{@var{n} = 1}, |
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or @var{msgplural} otherwise. When translated, the message catalog |
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can have a different rule, and can have more than two possible forms. |
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As per @code{gettext} above, normal usage is for @var{msg} and |
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@var{msgplural} to be literal strings, since @command{xgettext} can |
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extract them from the source to build a message catalog. For |
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example, |
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@example |
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(define (done n) |
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(format #t (ngettext "~a file processed\n" |
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"~a files processed\n" n) |
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n)) |
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(done 1) @print{} 1 file processed |
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(done 3) @print{} 3 files processed |
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@end example |
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It's important to use @code{ngettext} rather than plain @code{gettext} |
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for plurals, since the rules for singular and plural forms in English |
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are not the same in other languages. Only @code{ngettext} will allow |
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translators to give correct forms (@pxref{Plural forms,, Additional |
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functions for plural forms, gettext, GNU @code{gettext} utilities}). |
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@end deffn |
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@deffn {Scheme Procedure} textdomain [domain] |
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@deffnx {C Function} scm_textdomain (domain) |
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Get or set the default gettext domain. When called with no parameter |
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the current domain is returned. When called with a parameter, |
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@var{domain} is set as the current domain, and that new value |
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returned. For example, |
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@example |
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(textdomain "myprog") |
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@result{} "myprog" |
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@end example |
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@end deffn |
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@deffn {Scheme Procedure} bindtextdomain domain [directory] |
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@deffnx {C Function} scm_bindtextdomain (domain, directory) |
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Get or set the directory under which to find message files for |
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@var{domain}. When called without a @var{directory} the current |
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setting is returned. When called with a @var{directory}, |
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@var{directory} is set for @var{domain} and that new setting returned. |
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For example, |
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@example |
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(bindtextdomain "myprog" "/my/tree/share/locale") |
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@result{} "/my/tree/share/locale" |
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@end example |
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When using Autoconf/Automake, an application should arrange for the |
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configured @code{localedir} to get into the program (by substituting, |
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or by generating a config file) and set that for its domain. This |
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ensures the catalog can be found even when installed in a |
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non-standard location. |
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@end deffn |
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@deffn {Scheme Procedure} bind-textdomain-codeset domain [encoding] |
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@deffnx {C Function} scm_bind_textdomain_codeset (domain, encoding) |
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Get or set the text encoding to be used by @code{gettext} for messages |
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from @var{domain}. @var{encoding} is a string, the name of a coding |
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system, for instance @nicode{"8859_1"}. (On a Unix/POSIX system the |
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@command{iconv} program can list all available encodings.) |
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When called without an @var{encoding} the current setting is returned, |
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or @code{#f} if none yet set. When called with an @var{encoding}, it |
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is set for @var{domain} and that new setting returned. For example, |
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@example |
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(bind-textdomain-codeset "myprog") |
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@result{} #f |
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(bind-textdomain-codeset "myprog" "latin-9") |
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@result{} "latin-9" |
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@end example |
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The encoding requested can be different from the translated data file, |
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messages will be recoded as necessary. But note that when there is no |
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translation, @code{gettext} returns its @var{msg} unchanged, ie.@: |
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without any recoding. For that reason source message strings are best |
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as plain ASCII. |
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Currently Guile has no understanding of multi-byte characters, and |
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string functions won't recognize character boundaries in multi-byte |
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strings. An application will at least be able to pass such strings |
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through to some output though. Perhaps this will change in the |
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future. |
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@end deffn |
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@c Local Variables: |
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@c TeX-master: "guile.texi" |
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@c ispell-local-dictionary: "american" |
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@c End: |
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