doc: Update for new behaviour of line breaking functions.

* doc/unilbrk.texi (unilbrk.h): Document UC_BREAK_CR_BEFORE_LF. Mention
that this value can occur in the array returned by
u*_possible_linebreaks and u*_width_linebreaks.
* NEWS: Mention the change.

3 files changed, 25 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 9215fba..cecab08 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2021-12-29  Bruno Haible  <bruno@clisp.org>
+
+	doc: Update for new behaviour of line breaking functions.
+	* doc/unilbrk.texi (unilbrk.h): Document UC_BREAK_CR_BEFORE_LF. Mention
+	that this value can occur in the array returned by
+	u*_possible_linebreaks and u*_width_linebreaks.
+	* NEWS: Mention the change.
+
 2021-12-26  Bruno Haible  <bruno@clisp.org>
 
 	doc: Update for Unicode 10.0.0.
diff --git a/NEWS b/NEWS
index 42b6cd2..f03c616 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,10 @@ New in 0.9.11:
 * The license has changed from "LGPLv3+ or GPLv2" to "LGPLv3+ or GPLv2+".
 * The functions u8_uctomb, u16_uctomb, u32_uctomb now support strings larger
   than 2 GiB by taking an 'n' argument of type ptrdiff_t (instead of int).
+* The functions u*_possible_linebreaks and u*_width_linebreaks now make it
+  easier to work with strings that contain CR-LF sequences: In this case,
+  in the returned array, it will return UC_BREAK_CR_BEFORE_LF followed by
+  UC_BREAK_MANDATORY (instead of twice UC_BREAK_MANDATORY).
 * Fixed multithread-safety bugs on Cygwin, native Windows, and Haiku.
 
 New in 0.9.10:
diff --git a/doc/unilbrk.texi b/doc/unilbrk.texi
index 91e5863..c068704 100644
--- a/doc/unilbrk.texi
+++ b/doc/unilbrk.texi
@@ -20,6 +20,12 @@ following meanings:
 This value indicates that @code{@var{s}[@var{i}]} is a line break character.
 @end deftypevr
 
+@deftypevr Constant int UC_BREAK_CR_BEFORE_LF
+This value is a variant of @code{UC_BREAK_MANDATORY}.  It indicates that
+@code{@var{s}[@var{i}]} is a CR character and that @code{@var{s}[@var{i+1}]}
+is a LF character.
+@end deftypevr
+
 @deftypevr Constant int UC_BREAK_POSSIBLE
 This value indicates that a line break may be inserted between
 @code{@var{s}[@var{i}-1]} and @code{@var{s}[@var{i}]}.
@@ -51,8 +57,9 @@ possible.
 @deftypefunx void ulc_possible_linebreaks (const@tie{}char@tie{}*@var{s}, size_t@tie{}@var{n}, const@tie{}char@tie{}*@var{encoding}, char@tie{}*@var{p})
 Determines the line break points in @var{s}, and stores the result at
 @code{@var{p}[0..@var{n}-1]}.  Every @code{@var{p}[@var{i}]} is assigned one of
-the values @code{UC_BREAK_MANDATORY}, @code{UC_BREAK_POSSIBLE},
-@code{UC_BREAK_HYPHENATION}, @code{UC_BREAK_PROHIBITED}.
+the values @code{UC_BREAK_MANDATORY}, @code{UC_BREAK_CR_BEFORE_LF},
+@code{UC_BREAK_POSSIBLE}, @code{UC_BREAK_HYPHENATION},
+@code{UC_BREAK_PROHIBITED}.
 @end deftypefun
 
 The following functions determine where line breaks should be inserted so that
@@ -82,7 +89,8 @@ The given @var{encoding} is used for disambiguating widths in @code{uc_width}.
 
 Returns the column after the end of the string, and stores the result at
 @code{@var{p}[0..@var{n}-1]}.  Every @code{@var{p}[@var{i}]} is assigned one of
-the values @code{UC_BREAK_MANDATORY}, @code{UC_BREAK_POSSIBLE},
-@code{UC_BREAK_HYPHENATION}, @code{UC_BREAK_PROHIBITED}.  Here the value
-@code{UC_BREAK_POSSIBLE} indicates that a line break @emph{should} be inserted.
+the values @code{UC_BREAK_MANDATORY}, @code{UC_BREAK_CR_BEFORE_LF},
+@code{UC_BREAK_POSSIBLE}, @code{UC_BREAK_HYPHENATION},
+@code{UC_BREAK_PROHIBITED}.  Here the value @code{UC_BREAK_POSSIBLE} indicates
+that a line break @emph{should} be inserted.
 @end deftypefun