GroffChar: added @ to list of standard escapes.

Because we use it as a delimiter for tables (in man)
and for math (in ms).

src/Text/Pandoc/GroffChar.hs

@@ -37,7 +37,8 @@ module Text.Pandoc.GroffChar (
   ) where
 import Prelude
 
--- | These are the escapes specifically mentioned in groff_man(7).
+-- | These are the escapes specifically mentioned in groff_man(7),
+-- plus @ and ellipsis.
 standardEscapes :: [(Char, String)]
 standardEscapes =
   [ ('\160', "\\ ")
@@ -54,6 +55,7 @@ standardEscapes =
   , ('~', "\\[ti]")
   , ('-', "\\-")  -- minus; - will be interpreted as hyphen U+2010
   , ('\\', "\\[rs]")
+  , ('@', "\\[at]") -- because we use @ as a table and math delimiter
   , ('\x2026', "\\&...")  -- because u2026 doesn't render on tty
   ]
 

test/writer.ms

@@ -925,7 +925,7 @@ It should.
 .LP
 An e\-mail address: \c
 .pdfhref W -D "mailto:nobody%40nowhere.net" -A "\c" \
- -- "nobody@nowhere.net"
+ -- "nobody\[at]nowhere.net"
 \&
 .RS
 .LP