* tmac/strip.sed: Strip `\#' also.

* doc/groff.texinfo: Document usage of \? for string comparison.

3 files changed, 47 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 67487227..e4a32260 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2006-06-05  Werner LEMBERG  <wl@gnu.org>
+
+	* tmac/strip.sed: Strip `\#' also.
+
+	* doc/groff.texinfo: Document usage of \? for string comparison.
+
 2006-06-04  Werner LEMBERG  <wl@gnu.org>
 
 	* doc/groff.texinfo: Add more index entries for copy-in mode.
diff --git a/doc/groff.texinfo b/doc/groff.texinfo
index 4a3cb3eb..bfdd8616 100644
--- a/doc/groff.texinfo
+++ b/doc/groff.texinfo
@@ -10586,8 +10586,9 @@ nodes inserted additionally by @code{gtroff}.
 @subsection Operators in Conditionals
 
 @cindex @code{if} request, operators to use with
+@cindex @code{ie} request, operators to use with
 @cindex @code{while} request, operators to use with
-In @code{if} and @code{while} requests, there are several more
+In @code{if}, @code{ie}, and @code{while} requests, there are several more
 operators available:
 
 @table @code
@@ -10608,10 +10609,12 @@ Always false.  This condition is for compatibility with other
 @code{troff} versions only (identifying a @code{-Tversatec} device).
 
 @item '@var{xxx}'@var{yyy}'
-True if the string @var{xxx} is equal to the string @var{yyy}.  Other
-characters can be used in place of the single quotes; the same set of
-delimiters as for the @code{\D} escape is used (@pxref{Escapes}).
-@code{gtroff} formats the strings before being compared:
+True if the output produced by @var{xxx} is equal to the output
+produced by @var{yyy}.  Other characters can be used in place of the
+single quotes; the same set of delimiters as for the @code{\D} escape
+is used (@pxref{Escapes}).  @code{gtroff} formats @var{xxx} and @var{yyy}
+in separate environments; after the comparison the resulting data is
+discarded.
 
 @Example
 .ie "|"\fR|\fP" \
@@ -10632,6 +10635,36 @@ at the same location on the page, so the strings are equal.  If
 would be ``false'' because (the first) @samp{|} produces an italic
 @samp{|} rather than a roman one.
 
+@cindex string comparison
+@cindex comparison of strings
+To compare strings without processing, surround the data with
+@code{\?}.
+
+@Example
+.ie "\?|\?"\?\fR|\fP\?" \
+true
+.el \
+false
+    @result{} false
+@endExample
+
+@cindex @code{\?}, and copy-in mode
+@cindex copy-in mode, and @code{\?}
+@cindex mode, copy-in, and @code{\?}
+@noindent
+Since data protected with @code{\?} is read in copy-in mode it is even
+possible to use incomplete input without causing an error.
+
+@Example
+.ds a \[
+.ds b \[
+.ie '\?\*a\?'\?\*b\?' \
+true
+.el \
+false
+    @result{} true
+@endExample
+
 @item r @var{xxx}
 True if there is a number register named @var{xxx}.
 
diff --git a/tmac/strip.sed b/tmac/strip.sed
index 069c3db1..0bb59f8f 100644
--- a/tmac/strip.sed
+++ b/tmac/strip.sed
@@ -1,8 +1,10 @@
-# strip comments, spaces, etc. after a line containing `%beginstrip%'
+# strip comments, spaces, etc., after a line containing `%beginstrip%'
 /%beginstrip%/,$ {
   s/^\.[	 ]*/./
   s/^\.\\".*/./
+  s/^\\#.*/./
   s/\\".*/\\"/
+  s/\\#.*/\\/
   /\(.[ad]s\)/!s/[	 ]*\\"//
   /\(.[ad]s\)/s/\([^	 ]*\)\\"/\1/
   s/\([^/]\)doc-/\1/g