[groff] 24/53: [me]: Add nroff strings for super-, subscripts.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 3252715c3b8696c373b88de7dd35f84c43d6a39e
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sun Dec 5 23:47:12 2021 +1100

    [me]: Add nroff strings for super-, subscripts.
    
    * tmac/e.tmac: Add nroff mode string definitions for 4.4BSD
      compatibility.
      - Define '{' and '}' (superscripting) strings as '[' and ']'.
      - Define '<' and '>' (subscripting) strings as '\(la and '\(ra' if
        available on the device, otherwise '<' and '>'.
    
    * tmac/tests/e_footnote-marks-work.sh: Update expected output.
    
    * doc/meref.me: Document it.
    
    Fixes <https://savannah.gnu.org/bugs/index.php?61619>.
---
 ChangeLog                           | 14 ++++++++++++++
 doc/meref.me                        | 15 +++++++++++++--
 tmac/e.tmac                         | 29 +++++++++++++++++++++++++++++
 tmac/tests/e_footnote-marks-work.sh |  6 +++---
 4 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a1d6000..18cd721 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -71,6 +71,20 @@
 
 2021-12-05  G. Branden Robinson <g.branden.robinson@gmail.com>
 
+       * tmac/e.tmac: Add nroff mode string definitions for 4.4BSD
+       compatibility.
+         - Define '{' and '}' (superscripting) strings as '[' and ']'.
+         - Define '<' and '>' (subscripting) strings as '\(la and
+           '\(ra' if available on the device, otherwise '<' and '>'.
+
+       * tmac/tests/e_footnote-marks-work.sh: Update expected output.
+
+       * doc/meref.me: Document it.
+
+       Fixes <https://savannah.gnu.org/bugs/index.php?61619>.
+
+2021-12-05  G. Branden Robinson <g.branden.robinson@gmail.com>
+
        * doc/doc.am (doc/meintro_fr.ps): Add target rule (overriding
        suffix rule) to generate this file using `-mfr` (load the French
        localization macro file).
diff --git a/doc/meref.me b/doc/meref.me
index d2c9f43..0756c62 100644
--- a/doc/meref.me
+++ b/doc/meref.me
@@ -1850,12 +1850,16 @@ This string gives upward movement
 and a change to a smaller point size.
 Extra space is left above the line
 to allow room for the superscript.
+In \*N mode,
+it produces a left square bracket.
 .TL
 .ST }
 .DE
 Unsuperscript.
 Inverse to
 .ST { .
+In \*N mode,
+it produces a right square bracket.
 For example,
 to produce a superscript
 you might type
@@ -1863,19 +1867,26 @@ you might type
 .ST { \c
 .b 2 \c
 .ST } ,
-which will produce
-.b x\*{2\*} .
+which will render as
+.b x\*{2\*}
+on typesetters and as
+.b x[2]
+on terminals.
 .TL
 .ST <
 .DE
 Subscript.
 Extra space is left below the line
 to allow for the subscript.
+In \*N mode,
+it produces a left angle bracket.
 .TL
 .ST >
 .DE
 Inverse to
 .ST < .
+In \*N mode,
+it produces a right angle bracket.
 .TL
 .ST (dw
 .DE
diff --git a/tmac/e.tmac b/tmac/e.tmac
index bbb0353..291049a 100644
--- a/tmac/e.tmac
+++ b/tmac/e.tmac
@@ -1988,14 +1988,43 @@
 .\" GNU pic sets this register to 1 to indicate that \x should not be
 .\" used.
 .@R 0x
+.\" Define strings for super- and subscripting.  groff me does not
+.\" bother with half-line motions in nroff mode, since we have no output
+.\" driver (for that mode) that supports them; consequently we don't
+.\" emit \x escape sequences in that case either.  If someone implements
+.\" a Model 37 or line printer emulator we can target, this decision
+.\" could be revisited.
+.ie t \
+\{\
 .ds { \v'-0.4m'\x'\\n(0x=0*-0.2m'\s-3
 .ds } \s+3\v'0.4m'
+.\}
+.el \
+\{\
+.ds { [\"
+.ds } ]\"
+.\}
 .\" for compatibility with traditional -me
 .\" (the first will work only in compatibility mode)
 .ds [ \*{
 .ds ] \*}
+.ds @< <\"
+.ds @> >\"
+.if \n(.g \
+\{\
+.do if c \(la .ds @< \(la\"
+.do if c \(ra .ds @> \(ra\"
+.\}
+.ie t \
+\{\
 .ds < \v'0.4m'\x'\\n(0x=0*0.2m'\s-3
 .ds > \s+3\v'-0.4m'
+.\}
+.el \
+\{\
+.ds < \*(@<
+.ds > \*(@>
+.\}
 .ds - \(em
 .\" Avoid warnings from groff -ww.
 .@S |0
diff --git a/tmac/tests/e_footnote-marks-work.sh 
b/tmac/tests/e_footnote-marks-work.sh
index 031c8e3..616fa9c 100755
--- a/tmac/tests/e_footnote-marks-work.sh
+++ b/tmac/tests/e_footnote-marks-work.sh
@@ -45,18 +45,18 @@ of quartz.\**
 output=$(echo "$input" | "$groff" -Tascii -P-cbou -me)
 
 echo "$output" \
-    | grep -F 'Jackdaws* love my big1 sphinx** of quartz.2'
+    | grep -F 'Jackdaws* love my big[1] sphinx** of quartz.[2]'
 
 echo "$output" \
     | grep -F '* foo'
 
 echo "$output" \
-    | grep -F '1 bar'
+    | grep -F '[1] bar'
 
 echo "$output" \
     | grep -F '** baz'
 
 echo "$output" \
-    | grep -F '2 qux'
+    | grep -F '[2] qux'
 
 # vim:set ai et sw=4 ts=4 tw=72: