Re: backward-kill-word behavior

[Peter Stephenson <pws@pwstephenson.fsnet.co.uk>]

"Bart Schaefer" wrote:
> On Jun 25, 10:36pm, Peter Stephenson wrote:
> > 
> > We can supply functions that do this.  The deletion is a trivial one-line
> > parameter substitution.  However, pushing the deleted part onto the kill
> > ring appears to be rather harder.  You can manipulate point and mark, but
> > that messes up the user's state.  Is it really impossible to do this as the
> > internals do, or have I missed something?
> 
> Is there something wrong with:
> 
>     function bash-backward-kill-word {
> 	local WORDCHARS=''
> 	zle .backward-kill-word
>     }

No, apart from it not being very flexible.  If bash compatibility is all
you want, that should be fine.

Here's my proposal for allowing text to be put into the kill buffer (and
hence onto the kill ring).  I put together some functions to use these with
patterns instead of character list for words, which I may rewrite a bit
more, although the default effect is identical to the above.

Index: Doc/Zsh/zle.yo
===================================================================
RCS file: /cvsroot/zsh/zsh/Doc/Zsh/zle.yo,v
retrieving revision 1.13
diff -u -r1.13 zle.yo
--- Doc/Zsh/zle.yo	2001/04/19 19:43:45	1.13
+++ Doc/Zsh/zle.yo	2001/06/25 22:46:44
@@ -295,6 +295,7 @@
 xitem(tt(zle) tt(-C) var(widget) var(completion-widget) var(function))
 xitem(tt(zle) tt(-R) [ tt(-c) ] [ var(display-string) ] [ var(string) ... ])
 xitem(tt(zle) tt(-M) var(string))
+xitem(tt(zle) tt(-P) [ tt(-bk) ] var(string))
 xitem(tt(zle) tt(-U) var(string))
 xitem(tt(zle) tt(-I))
 xitem(tt(zle) var(widget) tt([ -n) var(num) tt(]) tt([ -N ]) var(args) ...)
@@ -374,6 +375,16 @@
 the status line but will instead be printed normally below the
 prompt.  This means that the var(string) will still be displayed after
 the widget returns (until it is overwritten by subsequent commands).
+)
+item(tt(-P) [ tt(-bk) ] var(string))(
+This puts var(string) into zsh's kill buffer for use with a subsequent
+tt(yank), causing the kill-ring to be rotated.   By default, var(string)
+will simply overwrite the text in the buffer; if the tt(-k) option is
+given, it behaves instead like a kill command in that subsequent kills or
+calls to tt(zle -P) cause var(string) to be appended to the existing text
+in the kill buffer.  If the flag tt(-b) is given, the the var(string) is
+instead inserted before any existing text in the kill buffer; this is used
+when emulating kills in the backward direction.
 )
 item(tt(-U) var(string))(
 This pushes the characters in the var(string) onto the input stack of
Index: Src/Zle/zle_main.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_main.c,v
retrieving revision 1.18
diff -u -r1.18 zle_main.c
--- Src/Zle/zle_main.c	2001/05/17 15:56:13	1.18
+++ Src/Zle/zle_main.c	2001/06/25 22:47:01
@@ -93,6 +93,11 @@
 /**/
 mod_export int lastcmd;
 
+/* flags to be or'd into lastcmd for present command */
+
+/**/
+mod_export int thiscmd;
+
 /**/
 mod_export Widget compwidget;
 
@@ -526,7 +531,7 @@
 #endif
     undoing = 1;
     line = (unsigned char *)zalloc((linesz = 256) + 2);
-    virangeflag = lastcmd = done = cs = ll = mark = 0;
+    virangeflag = lastcmd = thiscmd = done = cs = ll = mark = 0;
     vichgflag = 0;
     viinsbegin = 0;
     statusline = NULL;
@@ -701,7 +706,8 @@
 	    lastval = olv;
 	    sfcontext = osc;
 	    endparamscope();
-	    lastcmd = 0;
+	    lastcmd = thiscmd;
+	    thiscmd = 0;
 	    r = 1;
 	    redup(osi, 0);
 	}
@@ -1096,7 +1102,7 @@
 static struct builtin bintab[] = {
     BUILTIN("bindkey", 0, bin_bindkey, 0, -1, 0, "evaMldDANmrsLRp", NULL),
     BUILTIN("vared",   0, bin_vared,   1,  7, 0, NULL,             NULL),
-    BUILTIN("zle",     0, bin_zle,     0, -1, 0, "lDANCLmMgGcRaUI", NULL),
+    BUILTIN("zle",     0, bin_zle,     0, -1, 0, "AabCcDGgIkLlMmNPRU", NULL),
 };
 
 /* The order of the entries in this table has to match the *HOOK
Index: Src/Zle/zle_thingy.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_thingy.c,v
retrieving revision 1.3
diff -u -r1.3 zle_thingy.c
--- Src/Zle/zle_thingy.c	2000/11/11 19:50:29	1.3
+++ Src/Zle/zle_thingy.c	2001/06/25 22:47:03
@@ -340,6 +340,7 @@
 	{ 'M', bin_zle_mesg, 1, 1 },
 	{ 'U', bin_zle_unget, 1, 1 },
 	{ 'I', bin_zle_invalidate, 0, 0 },
+	{ 'P', bin_zle_push, 1, 1 },
 	{ 0,   bin_zle_call, 0, -1 },
     };
     struct opn const *op, *opp;
@@ -664,6 +665,20 @@
 	return 0;
     } else
 	return 1;
+}
+
+/**/
+static int
+bin_zle_push(char *name, char **args, char *ops, char func)
+{
+    if (!zleactive) {
+	zwarnnam(name, "can only be called from widget function", NULL, 0);
+	return 1;
+    }
+    push_kring(*args, ops['b']);
+    if (ops['k'] || ops['b'])
+	thiscmd |= ZLE_KILL;
+    return 0;
 }
 
 /*******************/
Index: Src/Zle/zle_utils.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_utils.c,v
retrieving revision 1.6
diff -u -r1.6 zle_utils.c
--- Src/Zle/zle_utils.c	2001/03/26 08:58:34	1.6
+++ Src/Zle/zle_utils.c	2001/06/25 22:47:03
@@ -125,6 +125,40 @@
 }
 
 /**/
+static void
+paste(char *str, int ct, int dir)
+{
+    if (!cutbuf.buf) {
+	cutbuf.buf = ztrdup("");
+	cutbuf.len = cutbuf.flags = 0;
+    } else if (!(lastcmd & ZLE_KILL)) {
+	kringnum = (kringnum + 1) % KRINGCT;
+	if (kring[kringnum].buf)
+	    free(kring[kringnum].buf);
+	kring[kringnum] = cutbuf;
+	cutbuf.buf = ztrdup("");
+	cutbuf.len = cutbuf.flags = 0;
+    }
+    if (dir) {
+	char *s = (char *)zalloc(cutbuf.len + ct);
+
+	memcpy(s, str, ct);
+	memcpy(s + ct, cutbuf.buf, cutbuf.len);
+	free(cutbuf.buf);
+	cutbuf.buf = s;
+	cutbuf.len += ct;
+    } else {
+	cutbuf.buf = realloc(cutbuf.buf, cutbuf.len + ct);
+	memcpy(cutbuf.buf + cutbuf.len, str, ct);
+	cutbuf.len += ct;
+    }
+    if(vilinerange)
+	cutbuf.flags |= CUTBUFFER_LINE;
+    else
+	cutbuf.flags &= ~CUTBUFFER_LINE;
+}
+
+/**/
 void
 cut(int i, int ct, int dir)
 {
@@ -163,34 +197,17 @@
 	vibuf[26].len = ct;
 	vibuf[26].flags = vilinerange ? CUTBUFFER_LINE : 0;
     }
-    if (!cutbuf.buf) {
-	cutbuf.buf = ztrdup("");
-	cutbuf.len = cutbuf.flags = 0;
-    } else if (!(lastcmd & ZLE_KILL)) {
-	kringnum = (kringnum + 1) % KRINGCT;
-	if (kring[kringnum].buf)
-	    free(kring[kringnum].buf);
-	kring[kringnum] = cutbuf;
-	cutbuf.buf = ztrdup("");
-	cutbuf.len = cutbuf.flags = 0;
-    }
-    if (dir) {
-	char *s = (char *)zalloc(cutbuf.len + ct);
+    paste((char *)line + i, ct, dir);
+}
 
-	memcpy(s, (char *) line + i, ct);
-	memcpy(s + ct, cutbuf.buf, cutbuf.len);
-	free(cutbuf.buf);
-	cutbuf.buf = s;
-	cutbuf.len += ct;
-    } else {
-	cutbuf.buf = realloc(cutbuf.buf, cutbuf.len + ct);
-	memcpy(cutbuf.buf + cutbuf.len, (char *) line + i, ct);
-	cutbuf.len += ct;
-    }
-    if(vilinerange)
-	cutbuf.flags |= CUTBUFFER_LINE;
-    else
-	cutbuf.flags &= ~CUTBUFFER_LINE;
+/**/
+mod_export void
+push_kring(char *str, int dir)
+{
+    int len;
+
+    unmetafy(str, &len);
+    paste(str, len, dir);
 }
 
 /**/