Re: delete-to-char

[Peter Stephenson <pws@xxxxxxxxxxxxxxxxx>]

Vin Shelton wrote:
> >>>>> On 20 Sep 1999, I wrote:
> 
> Vin> OK, I'm waking up to the new world of modules and I came across the
> Vin> deltochar module and the delete-to-char function.  I hope I'm not
> Vin> rehashing an old discussion, but both XEmacs (as of 21.0) and FSF
> Vin> Emacs (as of at least 20.4) now define zap-to-char as deleting up to
> Vin> but not including the specified character.  It would be good, IMHO, to
> Vin> have delete-to-char model that functionality.  Currently
> Vin> delete-to-char deletes up to and including the specified character.

Sorry, I meant to reply to this before.  I hadn't changed it before,
firstly because I never understood why they changed the behaviour and don't
like the new one, and secondly because since I wrote delete-to-char it's
become easy to do the same thing as a shell function, which I've included
below.  (Actually, until Sven adapted read -k quite recently, it
wasn't that easy.)  But Sven's right that it should really be in a different
widget.  The patch at the end, after the function, uses your code
to adapt the deltochar() function, but only when called from a different
widget zap-to-char; this makes the change very economical.

> Not waiting for the bits to dry, I generated this patch.  In the
> course of testing this, I found that M-digit did not work for me with
> bindkey -me, even though bindkey thinks they are bound to
> digit-argument.  M-anydigit just beeps.  "od -x" tells me that M-0
> sends 0xb0, M-1 sends 0xb1, etc.  Do I have my xterm/stty settings
> wrong, or is this a bug in zsh.

The other meta things, like M-x, work, right?  I'm having the same problem.
I thought it was just my terminal, but maybe it's zsh.  If I type M-1 it
just beeps, but if I type `bindkey "', then a quoted M-1, then `"<RETURN>',
it says
"\M-1" digit-argument
so something a little weird is happening.


emulate -L zsh
setopt extendedglob

integer num=${NUMERIC:-1} ret
local key match mbegin mend oldrbuf="$RBUFFER" oldlbuf="$LBUFFER"

read -k key
while (( num )); do
  if (( num > 0 )); then
    if [[ $RBUFFER = (#b)[^$key]#$key(*) ]]; then
      if (( num == 1 )); then
	RBUFFER=$key${match[1]}
      else
	RBUFFER=${match[1]}
      fi
      (( num-- ))
    else
      ret=1
      RBUFFER="$oldrbuf"
      break
    fi
  else
    if [[ $LBUFFER = (#b)(*)${key}[^$key]# ]]; then
      if (( num == -1 )); then
	LBUFFER=${match[1]}$key
      else
	LBUFFER=${match[1]}
      fi
      (( num++ ))
    else
      ret=1
      LBUFFER="$oldlbuf"
      break
    fi
  fi
done

return $ret


--- Doc/Zsh/mod_deltochar.yo.dc2	Thu Sep 23 10:31:21 1999
+++ Doc/Zsh/mod_deltochar.yo	Thu Sep 23 10:51:15 1999
@@ -1,6 +1,6 @@
 texinode(The deltochar Module)(The example Module)(The complist Module)(Zsh Modules)
 sect(The deltochar Module)
-The tt(deltochar) module makes available one ZLE function:
+The tt(deltochar) module makes available two ZLE functions:
 
 startitem()
 tindex(delete-to-char)
@@ -8,5 +8,11 @@
 Read a character from the keyboard, and
 delete from the cursor position up to and including the next
 (or, with repeat count var(n), the var(n)th) instance of that character.
+Negative repeat counts mean delete backwards.
+)
+tindex(zap-to-char)
+item(tt(zap-to-char))(
+This behaves like tt(delete-to-char), except that the final occurence of
+the character itself is not deleted.
 )
 enditem()
--- Src/Zle/deltochar.c.dc2	Thu Sep 23 10:31:21 1999
+++ Src/Zle/deltochar.c	Thu Sep 23 10:52:27 1999
@@ -31,19 +31,22 @@
 #include "deltochar.pro"
 
 static Widget w_deletetochar;
+static Widget w_zaptochar;
 
 /**/
 static int
 deltochar(char **args)
 {
     int c = getkey(0), dest = cs, ok = 0, n = zmult;
+    int zap = (bindk->widget == w_zaptochar);
 
     if (n > 0) {
 	while (n-- && dest != ll) {
 	    while (dest != ll && line[dest] != c)
 		dest++;
 	    if (dest != ll) {
-		dest++;
+		if (!zap || n > 0)
+		    dest++;
 		if (!n) {
 		    forekill(dest - cs, 0);
 		    ok++;
@@ -59,7 +62,7 @@
 		dest--;
 	    if (line[dest] == c) {
 		if (!n) {
-		    backkill(cs - dest, 1);
+		    backkill(cs - dest - zap, 1);
 		    ok++;
 		}
 		if (dest)
@@ -83,9 +86,14 @@
 {
     w_deletetochar = addzlefunction("delete-to-char", deltochar,
                                     ZLE_KILL | ZLE_KEEPSUFFIX);
-    if (w_deletetochar)
-	return 0;
-    zwarnnam(m->nam, "name clash when adding ZLE function `delete-to-char'",
+    if (w_deletetochar) {
+	w_zaptochar = addzlefunction("zap-to-char", deltochar,
+				     ZLE_KILL | ZLE_KEEPSUFFIX);
+	if (w_zaptochar)
+	    return 0;
+	deletezlefunction(w_deletetochar);
+    }
+    zwarnnam(m->nam, "deltochar: name clash when adding ZLE functions",
 	     NULL, 0);
     return -1;
 }
@@ -97,6 +105,7 @@
 cleanup_deltochar(Module m)
 {
     deletezlefunction(w_deletetochar);
+    deletezlefunction(w_zaptochar);
     return 0;
 }
 
-- 
Peter Stephenson <pws@xxxxxxxxxxxxxxxxx>       Tel: +39 050 844536
WWW:  http://www.ifh.de/~pws/
Dipartimento di Fisica, Via Buonarroti 2, 56127 Pisa, Italy