28042: transpose-lines widget

ChangeLog

@@ -1,3 +1,8 @@
+2010-06-16  Peter Stephenson  <p.w.stephenson@ntlworld.com>
+
+	* 28042: Doc/Zsh/contrib.yo, Functions/Zle/.distfiles,
+	Functions/Zle/transpose-lines: new widget.
+
 2010-06-14  Peter Stephenson  <pws@csr.com>
 
 	* 28038: Index: Completion/Zsh/Command/_zstyle, Doc/Zsh/calsys.yo,
@@ -13297,5 +13302,5 @@
 
 *****************************************************
 * This is used by the shell to define $ZSH_PATCHLEVEL
-* $Revision: 1.5005 $
+* $Revision: 1.5006 $
 *****************************************************

Doc/Zsh/contrib.yo

@@ -2073,6 +2073,23 @@ a true value, the search continues upward through the history.  When
 tt(auto-previous) is unset or false (the default), the widget must be
 invoked repeatedly in order to search earlier history lines.
 )
+tindex(transpose-lines)
+item(tt(transpose-lines))(
+Only useful with a multi-line editing buffer; the lines here are
+lines within the current on-screen buffer, not history lines.
+The effect is similar to the function of the same name in Emacs.
+
+Transpose the current line with the previous line and move the cursor
+to the start of the next line.  Repeating this (which can be done by
+providing a positive numeric prefix argument) has the effect of moving
+the line above the cursor down by a number of lines.
+
+With a negative numeric prefix argument, requires two lines above the
+cursor.  These two lines are transposed and the cursor moved to the
+start of the previous line.  Using a numeric prefix less than -1
+has the effect of moving the line above the cursor up by minus that
+number of lines.
+)
 tindex(which-command)
 item(tt(which-command))(
 This function is a drop-in replacement for the builtin widget

Functions/Zle/.distfiles

@@ -1,28 +1,45 @@
 DISTFILES_SRC='
 .distfiles
-backward-kill-word-match       backward-word-match
-capitalize-word-match          copy-earlier-word
-cycle-completion-positions     define-composed-chars
-delete-whole-word-match        down-case-word-match
-down-line-or-beginning-search  edit-command-line
-forward-word-match             history-beginning-search-menu
-history-pattern-search         history-search-end
-incarg                         incremental-complete-word
-insert-composed-char           insert-files
-insert-unicode-char            keeper
-keymap+widget                  kill-word-match
+backward-kill-word-match
+backward-word-match
+capitalize-word-match
+copy-earlier-word
+cycle-completion-positions
+define-composed-chars
+delete-whole-word-match
+down-case-word-match
+down-line-or-beginning-search
+edit-command-line
+forward-word-match
+history-beginning-search-menu
+history-pattern-search
+history-search-end
+incarg
+incremental-complete-word
+insert-composed-char
+insert-files
+insert-unicode-char
+keeper
+keymap+widget
+kill-word-match
 match-word-context
 match-words-by-style
 modify-current-argument
 narrow-to-region
-narrow-to-region-invisible     predict-on
-quote-and-complete-word        read-from-minibuffer
-replace-string                 select-word-style
+narrow-to-region-invisible
+predict-on
+quote-and-complete-word
+read-from-minibuffer
+replace-string
 replace-string-again
+select-word-style
 smart-insert-last-word
 split-shell-arguments
+transpose-lines
 transpose-words-match
-up-case-word-match             up-line-or-beginning-search
-url-quote-magic                which-command
+up-case-word-match
+up-line-or-beginning-search
+url-quote-magic
+which-command
 zed-set-file-name
 '

Functions/Zle/transpose-lines

@@ -0,0 +1,43 @@
+# Transpose lines.  This is like in emacs: with a positive argument
+# (default 1) the current line and the previous line are swapped and the
+# cursor goes down one line; with a negative argument the previous two
+# lines are swapped and the cursor goes up one line.
+
+emulate -L zsh
+setopt extendedglob # xtrace
+
+local -a match mbegin mend
+integer count=${NUMERIC:-1}
+local init prev lline final rrline
+
+if (( ${NUMERIC:-1} < 0 )); then
+  while (( count++ )); do
+    [[ $LBUFFER != (#b)(|*$'\n')([^$'\n']#$'\n')([^$'\n']#$'\n')([^$'\n']#) ]] && return 1
+    
+    LBUFFER=$match[1]$match[3]
+    RBUFFER=$match[2]$match[4]$RBUFFER
+  done
+else
+  while (( count-- )); do
+    [[ $LBUFFER != (#b)(*)$'\n'([^$'\n']#) ]] && return 1
+
+    prev=$match[1]
+    lline=$match[2]
+
+    if [[ $prev = (#b)(*$'\n')([^$'\n']#) ]]; then
+      init=$match[1]
+      prev=$match[2]
+    fi
+
+    if [[ $RBUFFER = (#b)([^$'\n']#)$'\n'(*) ]]; then
+      rline=$match[1]
+      final=$match[2]
+      prev+=$'\n'
+    else
+      rline=$RBUFFER
+    fi
+
+    LBUFFER=$init$lline$rline$'\n'$prev
+    RBUFFER=$final
+  done
+fi