Clarify and complete documentation for in-place reverse

[perl5.git] / pod / perlreguts.pod

diff --git a/pod/perlreguts.pod b/pod/perlreguts.pod
index 125a9f9..9c54ec4 100644 (file)
--- a/pod/perlreguts.pod
+++ b/pod/perlreguts.pod
@@ -385,7 +385,7 @@ A grammar form might be something like this:
 
 =head3 Debug Output
 
-In the 5.9.x development version of perl you can C<<use re Debug => 'PARSE'>>
+In the 5.9.x development version of perl you can C<< use re Debug => 'PARSE' >>
 to see some trace information about the parse process. We will start with some
 simple patterns and build up to more complex patterns.
 
@@ -810,13 +810,12 @@ value to other engine implementations.
 
 =item C<swap>
 
-C<swap> is an extra set of startp/endp stored in a C<regexp_paren_ofs>
-struct. This is used when the last successful match was from the same pattern
-as the current pattern, so that a partial match doesn't overwrite the
-previous match's results. When this field is data filled the matching
-engine will swap buffers before every match attempt. If the match fails,
-then it swaps them back. If it's successful it leaves them. This field
-is populated on demand and is by default null.
+C<swap> formerly was an extra set of startp/endp stored in a
+C<regexp_paren_ofs> struct. This was used when the last successful match
+was from the same pattern as the current pattern, so that a partial
+match didn't overwrite the previous match's results, but it caused a
+problem with re-entrant code such as trying to build the UTF-8 swashes.
+Currently unused and left for backward compatibility with 5.10.0.
 
 =item C<offsets>