linenoise: selection endpoint toggle with Ctrl-^.

* linenoise/linenoise.c (edit): Implemented.

* txr.1: Documented.

2 files changed, 17 insertions, 0 deletions

diff --git a/linenoise/linenoise.c b/linenoise/linenoise.c
index 782fdfde..7dd29aa5 100644
--- a/linenoise/linenoise.c
+++ b/linenoise/linenoise.c
@@ -1870,6 +1870,15 @@ static int edit(lino_t *l, const char *prompt)
                 l->dsel = l->dend = l->dpos;
             l->need_refresh = 1;
             break;
+        case CTL('^'):
+            if (l->selmode)
+            {
+                size_t tmp = l->dsel;
+                l->dsel = l->dend;
+                l->dend = l->dpos = tmp;
+                l->need_refresh = 1;
+            }
+            break;
         case CTL('Y'):
             yank_sel(l);
             clear_sel(l);
diff --git a/txr.1 b/txr.1
index 76fda8f6..273dd533 100644
--- a/txr.1
+++ b/txr.1
@@ -33909,6 +33909,14 @@ the mode.
 Tab completion, history navigation, history search and editing in an external
 editor all cancel visual selection mode.
 
+.NP* Selection Endpoint Toggle
+
+In visual selection, the starting point of the selection remains fixed, while
+the ending point tracks the movement of the cursor. The Ctrl-^ command will
+exchange the two points. The effect is that the cursor jumps to the opposite
+end of the selection. That end is now the ending point which tracks the cursor
+movement.
+
 .NP* Visual Copy
 
 The Ctrl-Y command ("yank") copies the selected text into a clipboard buffer.