Re: [Groff] : ASCII Minus Sign in man Pages

[Ingo Schwarze]

Hi,

Ingo Schwarze wrote on Tue, May 02, 2017 at 03:45:01PM +0200:

> By the way, in the meantime, i also received support from NetBSD/pkgsrc
> for my proposal (\- always U+002D, \(mi always U+2212).  That's
> Ralph, Branden, NetBSD/pkgsrc, and one relevant FreeBSD developer
> then, and no protest so far from OpenBSD.  I think i'll start
> preparing patches and submit them to the groff bugtracker when they
> are ready.

Let's do that in slow, careful steps.

I just submitted the first, less intrusive patch:

  https://savannah.gnu.org/bugs/index.php?50917
  Make \- consistently render as U+002D across all macro sets and devices

For easy access, i'm also appending the patch below.

See the bug notes for remarks regarding non-UTF-8 output devices.

Comments are welcome, and if consensus emerges, so is a commit.

After that, i would then move on to the next step and submit a patch
to always render unescaped "-" as U+2010 HYPHEN.  Of course, it would
be OK to accept this first patch but reject or delay that second one.

Yours,
  Ingo



diff --git a/font/devutf8/NOTES b/font/devutf8/NOTES
index 8e724703..cd997ac2 100644
--- a/font/devutf8/NOTES
+++ b/font/devutf8/NOTES
@@ -6,9 +6,10 @@ Kernighan) is unmapped:
 
   bs    shaded solid ball (Bell System logo, AT&T logo)
 
-Character 0x002D has not been given a name because its Unicode name
-HYPHEN-MINUS is so ambiguous that it is unusable for serious typographic
-use.
+Even though its Unicode name HYPHEN-MINUS is so ambiguous that it
+is unusable for serious typographic use, the character 0x002D is
+needed to describe the syntax of many programming languages and to
+represent code samples.  It can be obtained with `\-'.
 
 \[wp] has been mapped to 0x2118, because according to Unicode 4.1's
 NamesList.txt, U+2118 SCRIPT CAPITAL P is really a Weierstrass `p',
diff --git a/man/groff_char.7.man b/man/groff_char.7.man
index e38c70b9..a77ca08c 100644
--- a/man/groff_char.7.man
+++ b/man/groff_char.7.man
@@ -279,6 +279,9 @@ hyphen (Unicode u2010).
 The same output glyph can be requested explicitly
 with \[oq]\f(CW\e(hy\fP\[cq].
 A minus sign can be obtained with \[oq]\f(CW\e(mi\fP\[cq] (Unicode u2212).
+To describe programming language syntax or present code samples,
+the original character can be obtained
+with \[oq]\f(CW\e-\fP\[cq] (Unicode u002D).
 .
 .
 .TP
@@ -315,6 +318,7 @@ _
 \[char43]      \[char43]       43      plus    u002B   plus
 \[char44]      \[char44]       44      comma   u002C   comma
 \[char45]      \[char45]       45      hyphen  u2010   hyphen
+\-     \e-             minus   u002D   hyphen-minus
 \[char46]      \[char46]       46      period  u002E   period, dot
 \[char47]      \[char47]       47      slash   u002F   slash
 \[char58]      \[char58]       58      colon   u003A   colon
@@ -753,6 +757,7 @@ _
 \[r?]  \e[r?]  questiondown    u00BF   inverted question mark
 \[em]  \e[em]  emdash  u2014   em-dash symbol +
 \[en]  \e[en]  endash  u2013   en-dash symbol
+\-     \e-     minus   u002D   ASCII hyphen-minus +
 \[hy]  \e[hy]  hyphen  u2010   hyphen symbol +
 .TE
 .ad
diff --git a/src/libs/libgroff/glyphuni.cpp b/src/libs/libgroff/glyphuni.cpp
index 62c81654..c94a37f8 100644
--- a/src/libs/libgroff/glyphuni.cpp
+++ b/src/libs/libgroff/glyphuni.cpp
@@ -55,6 +55,7 @@ struct S {
   { "+", "002B" },
   { "pl", "002B" },
   { ",", "002C" },
+  { "\\-", "002D" },
   { ".", "002E" },
   { "/", "002F" },
   { "sl", "002F" },
@@ -397,11 +398,6 @@ struct S {
   { "product", "220F" },
   { "coproduct", "2210" },
   { "sum", "2211" },
-  // `mi' and `\-' represent a MINUS sign.  But it is used in many man pages
-  // to denote the U+002D character that introduces a command-line option. 
-  // For devices that support copy&paste, such as devhtml and devutf8, the
-  // user can apply the workaround described in the PROBLEMS file.
-  { "\\-", "2212" },
   { "mi", "2212" },
   { "-+", "2213" },
   { "**", "2217" },
diff --git a/src/libs/libgroff/uniglyph.cpp b/src/libs/libgroff/uniglyph.cpp
index 3fafb225..2c773b8b 100644
--- a/src/libs/libgroff/uniglyph.cpp
+++ b/src/libs/libgroff/uniglyph.cpp
@@ -52,6 +52,7 @@ struct S {
 //{ "002B", "+" },
   { "002B", "pl" },
   { "002C", "," },
+  { "002D", "\\-" },
   { "002E", "." },
 //{ "002F", "/" },
   { "002F", "sl" },
@@ -390,7 +391,6 @@ struct S {
   { "2210", "coproduct" },
   { "2211", "sum" },
   { "2212", "mi" },
-//{ "2212", "\\-" },
   { "2213", "-+" },
   { "2217", "**" },
   { "221A", "sr" },
diff --git a/tmac/an-old.tmac b/tmac/an-old.tmac
index 1091e3d2..199baccd 100644
--- a/tmac/an-old.tmac
+++ b/tmac/an-old.tmac
@@ -676,9 +676,8 @@
 .\" of easy cut and paste.
 .
 .if '\*[.T]'utf8' \{\
-.  rchar \- - ' `
+.  rchar - ' `
 .
-.  char \- \N'45'
 .  char  - \N'45'
 .  char  ' \N'39'
 .  char  ` \N'96'
diff --git a/tmac/doc.tmac-u b/tmac/doc.tmac-u
index 8b7ad4cb..01eff136 100644
--- a/tmac/doc.tmac-u
+++ b/tmac/doc.tmac-u
@@ -6550,9 +6550,8 @@
 .\" of easy cut and paste.
 .
 .if '\*[.T]'utf8' \{\
-.  rchar \- - ' `
+.  rchar - ' `
 .
-.  char \- \N'45'
 .  char  - \N'45'
 .  char  ' \N'39'
 .  char  ` \N'96'
diff --git a/PROBLEMS b/PROBLEMS
index e0f1239a..c97f96f5 100644
--- a/PROBLEMS
+++ b/PROBLEMS
@@ -107,7 +107,6 @@ those characters back to the ASCII characters, insert the 
following
 code snippet into the `troffrc' configuration file:
 
 .if '\*[.T]'utf8' \{\
-.  char \- \N'45'
 .  char  - \N'45'
 .  char  ' \N'39'
 .\}