Improved support for Unicode title case in Guile's string and character APIs.

* doc/ref/api-data.texi (Characters): Documentation for `char-titlecase'.
* doc/ref/api-i18n.texi (Character Case Mapping): Documentation for
  `char-locale-titlecase' and `string-locale-titlecase'.

* libguile/chars.c, libguile/chars.h (scm_char_titlecase, scm_c_titlecase): New
  functions.

* libguile/i18n.c, libguile/i18n.h (chr_to_case, scm_char_locale_titlecase,
  str_to_case, scm_string_locale_titlecase): New functions.
* libguile/i18n.c (scm_char_locale_downcase, scm_char_locale_upcase,
  scm_string_locale_downcase, scm_string_locale_upcase): Refactor to share code
  via chr_to_case and str_to_case, as appropriate.
* module/ice-9/i18n.scm (char-locale-title-case, string-locale-titlecase): New
  functions.

* libguile/srfi-13.c (string_titlecase_x): Use uc_totitle instead of uc_toupper.

* test-suite/tests/chars.test: Tests for `char-titlecase'.
* test-suite/tests/i18n.test: Tests for `char-locale-titlecase' and
  `string-locale-titlecase'.
* test-suite/tests/srfi-13.test: Tests for `string-titlecase'.

1 files changed, 12 insertions, 0 deletions

diff --git a/doc/ref/api-i18n.texi b/doc/ref/api-i18n.texi
index ee76544eb..b82a3a276 100644
--- a/doc/ref/api-i18n.texi
+++ b/doc/ref/api-i18n.texi
@@ -197,6 +197,12 @@ Return the uppercase character that corresponds to @var{chr} according
 to either @var{locale} or the current locale.
 @end deffn
 
+@deffn {Scheme Procedure} char-locale-titlecase chr [locale]
+@deffnx {C Function} scm_char_locale_titlecase (chr, locale)
+Return the titlecase character that corresponds to @var{chr} according
+to either @var{locale} or the current locale.
+@end deffn
+
 @deffn {Scheme Procedure} string-locale-upcase str [locale]
 @deffnx {C Function} scm_string_locale_upcase (str, locale)
 Return a new string that is the uppercase version of @var{str}
@@ -209,6 +215,12 @@ Return a new string that is the down-case version of @var{str}
 according to either @var{locale} or the current locale.
 @end deffn
 
+@deffn {Scheme Procedure} string-locale-titlecase str [locale]
+@deffnx {C Function} scm_string_locale_titlecase (str, locale)
+Return a new string that is the titlecase version of @var{str}
+according to either @var{locale} or the current locale.
+@end deffn
+
 Note that in the current implementation Guile has no notion of
 multibyte characters and in a multibyte locale characters may not be
 converted correctly.