libtextstyle: Add ostream_printf, ostream_vprintf functions.

Suggested by José Marchesi.

* libtextstyle/autogen.sh (GNULIB_MODULES): Add 'vasprintf-posix'.
* libtextstyle/gnulib-local/lib/ostream.oo.h: Include <stdarg.h>.
(ostream_printf, ostream_vprintf): New declarations.
* libtextstyle/gnulib-local/lib/ostream.oo.c: Include <stdio.h>.
(ostream_printf, ostream_vprintf): New functions.
* libtextstyle/gnulib-local/lib/styled-ostream.oo.h: Update comments.
* libtextstyle/gnulib-local/lib/term-ostream.oo.h: Likewise.
* libtextstyle/gnulib-local/lib/html-ostream.oo.h: Likewise.
* libtextstyle/lib/textstyle.h: Include <stdio.h>.
(ostream_printf, ostream_vprintf): New functions.
(styled_ostream_flush_to_current_style, term_ostream_flush_to_current_style,
html_ostream_flush_to_current_style): Update comments.
* libtextstyle/doc/libtextstyle.texi (The ostream class): Document
ostream_printf, ostream_vprintf.
(The styled_ostream class, The term_ostream class, The html_ostream class):
Update comments.
* libtextstyle/NEWS: Mention it.
* NEWS: Likewise.

1 files changed, 11 insertions, 3 deletions

diff --git a/libtextstyle/doc/libtextstyle.texi b/libtextstyle/doc/libtextstyle.texi
index f65a0f928..1dd344152 100644
--- a/libtextstyle/doc/libtextstyle.texi
+++ b/libtextstyle/doc/libtextstyle.texi
@@ -853,6 +853,14 @@ Writes a sequence of bytes to a stream.
 Writes a string's contents to a stream.
 @end deftypefn
 
+@deftypefn Function ptrdiff_t ostream_printf (ostream_t@tie{}@var{stream}, const@tie{}char@tie{}*@var{format}, ...)
+@deftypefnx Function ptrdiff_t ostream_vprintf (ostream_t@tie{}@var{stream}, const@tie{}char@tie{}*@var{format}, va_list args)
+Writes formatted output to a stream.
+
+These functions return the size of formatted output, or a negative value
+in case of an error.
+@end deftypefn
+
 @deftypefn Function void ostream_flush (ostream_t@tie{}@var{stream}, ostream_flush_scope_t@tie{}@var{scope})
 Brings buffered data to its destination.
 @end deftypefn
@@ -918,7 +926,7 @@ instead of with the default text style.
 
 After calling this function, you can output strings without newlines(!) to the
 underlying stream, and they will be rendered like strings passed to
-@code{ostream_write_mem} or @code{ostream_write_str}.
+@code{ostream_write_mem}, @code{ostream_write_str}, or @code{ostream_printf}.
 @end deftypefn
 
 @node ostream subclasses without styling
@@ -1062,7 +1070,7 @@ instead of with the default text attributes.
 
 After calling this function, you can output strings without newlines(!) to the
 underlying file descriptor, and they will be rendered like strings passed to
-@code{ostream_write_mem} or @code{ostream_write_str}.
+@code{ostream_write_mem}, @code{ostream_write_str}, or @code{ostream_printf}.
 @end deftypefn
 
 @node The html_ostream class
@@ -1129,7 +1137,7 @@ instead of with the default text style.
 
 After calling this function, you can output strings without newlines(!) to the
 underlying stream, and they will be rendered like strings passed to
-@code{ostream_write_mem} or @code{ostream_write_str}.
+@code{ostream_write_mem}, @code{ostream_write_str}, or @code{ostream_printf}.
 @end deftypefn
 
 @node The memory_ostream class