Update the documentation of 'perform-replace'

* doc/lispref/searching.texi (Search and Replace): Update the
documentation of 'perform-replace'.

1 files changed, 8 insertions, 2 deletions

diff --git a/doc/lispref/searching.texi b/doc/lispref/searching.texi
index e759967aa8a..fca877117d9 100644
--- a/doc/lispref/searching.texi
+++ b/doc/lispref/searching.texi
@@ -1751,13 +1751,14 @@ of matching @var{regexp} against a substring of @var{string}.
   If you want to write a command along the lines of @code{query-replace},
 you can use @code{perform-replace} to do the work.
 
-@defun perform-replace from-string replacements query-flag regexp-flag delimited-flag &optional repeat-count map start end
+@defun perform-replace from-string replacements query-flag regexp-flag delimited-flag &optional repeat-count map start end backward region-noncontiguous-p
 This function is the guts of @code{query-replace} and related
 commands.  It searches for occurrences of @var{from-string} in the
 text between positions @var{start} and @var{end} and replaces some or
 all of them.  If @var{start} is @code{nil} (or omitted), point is used
 instead, and the end of the buffer's accessible portion is used for
-@var{end}.
+@var{end}.  (If the optional argument @var{backward} is
+non-@code{nil}, the search starts at @var{end} and goes backward.)
 
 If @var{query-flag} is @code{nil}, it replaces all
 occurrences; otherwise, it asks the user what to do about each one.
@@ -1789,6 +1790,11 @@ user responses for queries.  The argument @var{map}, if
 non-@code{nil}, specifies a keymap to use instead of
 @code{query-replace-map}.
 
+Non-@code{nil} @var{region-noncontiguous-p} means that the region
+between @var{start} and @var{end} is composed of noncontiguous pieces.
+The most common example of this is a rectangular region, where the
+pieces are separated by newline characters.
+
 This function uses one of two functions to search for the next
 occurrence of @var{from-string}.  These functions are specified by the
 values of two variables: @code{replace-re-search-function} and