Re: doc: New chapter "Strings and Characters"

[Bruno Haible]

Paul Eggert wrote on 2023-05-16:
> Em dash (---) shouldn't have spaces around it; if you like those spaces 
> (which I kind of do) please use en dash (--).

I agree, also after reading [1] and [2]. Thanks for the advice. Done.

[1] https://en.wikipedia.org/wiki/Dash#En_dash_versus_em_dash
[2] 
https://www.smashingmagazine.com/2011/08/mind-your-en-and-em-dashes-typographic-etiquette/


2023-06-19  Bruno Haible  <bruno@clisp.org>

        doc: Use "spaced en dash" style instead of "spaced em dash" style.
        Suggested by Paul Eggert.
        * doc/gnulib.texi: At sentence level, use "spaced en dash" style instead
        of "spaced em dash" style.
        * doc/gnulib-intro.texi: Likewise.
        * doc/multithread.texi: Likewise.
        * doc/strings.texi: Likewise.

diff --git a/doc/gnulib-intro.texi b/doc/gnulib-intro.texi
index c9478d3792..7d7168325c 100644
--- a/doc/gnulib-intro.texi
+++ b/doc/gnulib-intro.texi
@@ -486,7 +486,7 @@
 license.  Most often, they are under the same license.  But files can be
 shared among several modules, and in these cases it can happen that a
 source file is under a weaker license than noted in the module
-description --- namely under the weakest license among the licenses of
+description -- namely under the weakest license among the licenses of
 the modules that contain the file.
 
 Different licenses apply to files in special directories:
diff --git a/doc/gnulib.texi b/doc/gnulib.texi
index 4b47749fe6..f36a0cf720 100644
--- a/doc/gnulib.texi
+++ b/doc/gnulib.texi
@@ -632,7 +632,7 @@
 invocation, you @strong{must} list the source file @code{lib/foo.c}
 in the @code{Files} section.  This is needed even if the module
 depends on another module that already lists @code{lib/foo.c} in its
-@code{Files} section --- because your module might be used among
+@code{Files} section -- because your module might be used among
 the test modules (in the directory specified through @samp{--tests-base})
 and the other module among the main modules (in the directory specified
 through @samp{--source-base}), and in this situation, the
@@ -7214,7 +7214,7 @@
 
 @code{autopull.sh} is a program for fetching dependencies that may
 require network accesses.  It manages the Git submodules, including
-Gnulib --- assuming that Gnulib is a Git submodule. It also can fetch
+Gnulib -- assuming that Gnulib is a Git submodule. It also can fetch
 the PO files for internationalized packages.
 
 @code{autogen.sh} is a program that is meant to be run after
diff --git a/doc/multithread.texi b/doc/multithread.texi
index eef724d2ae..87485e8580 100644
--- a/doc/multithread.texi
+++ b/doc/multithread.texi
@@ -222,7 +222,7 @@
 @section Optimizations of multithreaded code
 
 Despite all the optimizations of multithreading primitives that have been
-implemented over the years --- from
+implemented over the years -- from
 @url{https://en.wikipedia.org/wiki/Compare-and-swap,
 atomic operations in hardware},
 over @url{https://en.wikipedia.org/wiki/Futex, futexes} and
@@ -232,7 +232,7 @@
 @url{https://lwn.net/Articles/534758/, [1]}
 @url{https://www.gnu.org/software/libc/manual/html_node/Elision-Tunables.html,
 [2]})
---- single-threaded programs can still profit performance-wise from the
+-- single-threaded programs can still profit performance-wise from the
 assertion that they are single-threaded.
 
 Gnulib defines four facilities that help optimizing for the single-threaded
diff --git a/doc/strings.texi b/doc/strings.texi
index aa0830f1a5..131221f583 100644
--- a/doc/strings.texi
+++ b/doc/strings.texi
@@ -68,7 +68,7 @@
 locale is some environmental attribute that the user can choose.
 
 Depending on the encoding, in general, every character is represented by
-one or more bytes (up to 4 bytes in practice --- but
+one or more bytes (up to 4 bytes in practice -- but
 use @code{MB_LEN_MAX} instead of the number 4 in the code).
 @cindex unibyte locale
 @cindex multibyte locale
@@ -596,7 +596,7 @@
 @subsection The @code{char} type
 
 The @code{char} type is in the C language since the beginning in the
-1970ies, but --- due to its limitation of 256 possible values --- is no
+1970ies, but -- due to its limitation of 256 possible values -- is no
 longer the adequate type for storing a character.
 
 Technically, it is still adequate in unibyte locales.  But since most
@@ -641,7 +641,7 @@
 16-bit type.  This means that it can never accommodate an entire Unicode
 character.  Either the @code{wchar_t *} strings are limited to
 characters in UCS-2 (the ``Basic Multilingual Plane'' of Unicode), or
---- if @code{wchar_t *} strings are encoded in UTF-16 --- a
+-- if @code{wchar_t *} strings are encoded in UTF-16 -- a
 @code{wchar_t} represents only half of a character in the worst case,
 making the @posixheader{wctype.h} functions pointless.
 
@@ -649,8 +649,8 @@
 On Solaris and FreeBSD, the @code{wchar_t} encoding is locale dependent
 and undocumented.  This means, if you want to know any property of a
 @code{wchar_t} character, other than the properties defined by
-@posixheader{wctype.h} --- such as whether it's a dash, currency symbol,
-paragraph separator, or similar ---, you have to convert it to
+@posixheader{wctype.h} -- such as whether it's a dash, currency symbol,
+paragraph separator, or similar --, you have to convert it to
 @code{char *} encoding first, by use of the function @posixfunc{wctomb}.
 
 @item