Re: PATCH: Re: The `zle' command and traps

[Sven Wischnowsky <wischnow@informatik.hu-berlin.de>]

I wrote:

> ...
>
> > If we can restrict widgets to those that do "safe" things, then we can
> > allow "zle widgetname" and there's no need for the special parameters to
> > be visible directly to the trap function.  If instead we must prohibit
> > widget-calling entirely, then perhaps the parameters should be available
> > to the trap function.
> 
> No patch for that yet, either. The problem is that traps are called
> from the core (of course) and the zle module might not be there. Maybe 
> calling a hook in dotrapargs() so that zle can install its own hook
> function when it is loaded to make the parameters available read-only
> when zle is active. Or does this sound too complicated to anyone?

Well, it didn't look too complicated to me... this also documents in
zle.yo that the zle parameters are available in completion widgets and 
traps called when zle is active.


Bye
 Sven

diff -ru ../z.old/Doc/Zsh/zle.yo Doc/Zsh/zle.yo
--- ../z.old/Doc/Zsh/zle.yo	Tue Mar 14 10:39:02 2000
+++ Doc/Zsh/zle.yo	Tue Mar 14 10:42:35 2000
@@ -115,6 +115,9 @@
 when the widget function exits.  These special parameters in fact have
 local scope, like parameters created in a function using tt(local).
 
+Inside completion widgets and traps called while ZLE is active, these
+parameters are available read-only.
+
 startitem()
 vindex(BUFFER)
 item(tt(BUFFER) (scalar))(
diff -ru ../z.old/Src/Zle/zle_main.c Src/Zle/zle_main.c
--- ../z.old/Src/Zle/zle_main.c	Tue Mar 14 10:38:53 2000
+++ Src/Zle/zle_main.c	Tue Mar 14 10:41:09 2000
@@ -992,6 +992,28 @@
 	kungetct = 0;
 }
 
+/* Hook functions. Used to allow access to zle parameters if zle is
+ * active. */
+
+static int
+zlebeforetrap(Hookdef dummy, void *dat)
+{
+    if (zleactive) {
+	startparamscope();
+	makezleparams(1);
+    }
+    return 0;
+}
+
+static int
+zleaftertrap(Hookdef dummy, void *dat)
+{
+    if (zleactive)
+	endparamscope();
+
+    return 0;
+}
+
 static struct builtin bintab[] = {
     BUILTIN("bindkey", 0, bin_bindkey, 0, -1, 0, "evaMldDANmrsLR", NULL),
     BUILTIN("vared",   0, bin_vared,   1,  7, 0, NULL,             NULL),
@@ -1049,6 +1071,8 @@
 int
 boot_(Module m)
 {
+    addhookfunc("before_trap", (Hookfn) zlebeforetrap);
+    addhookfunc("after_trap", (Hookfn) zleaftertrap);
     addbuiltins(m->nam, bintab, sizeof(bintab)/sizeof(*bintab));
     addhookdefs(m->nam, zlehooks, sizeof(zlehooks)/sizeof(*zlehooks));
     return 0;
@@ -1063,6 +1087,8 @@
 	    NULL, 0);
 	return 1;
     }
+    deletehookfunc("before_trap", (Hookfn) zlebeforetrap);
+    deletehookfunc("after_trap", (Hookfn) zleaftertrap);
     deletebuiltins(m->nam, bintab, sizeof(bintab)/sizeof(*bintab));
     deletehookdefs(m->nam, zlehooks, sizeof(zlehooks)/sizeof(*zlehooks));
     return 0;
diff -ru ../z.old/Src/init.c Src/init.c
--- ../z.old/Src/init.c	Tue Mar 14 10:38:47 2000
+++ Src/init.c	Tue Mar 14 10:41:09 2000
@@ -90,6 +90,8 @@
 /**/
 mod_export struct hookdef zshhooks[] = {
     HOOKDEF("exit", NULL, HOOKF_ALL),
+    HOOKDEF("before_trap", NULL, HOOKF_ALL),
+    HOOKDEF("after_trap", NULL, HOOKF_ALL),
 };
 
 /* keep executing lists until EOF found */
diff -ru ../z.old/Src/signals.c Src/signals.c
--- ../z.old/Src/signals.c	Tue Mar 14 10:38:49 2000
+++ Src/signals.c	Tue Mar 14 10:41:09 2000
@@ -894,6 +894,7 @@
     lexsave();
     execsave();
     breaks = 0;
+    runhookdef(BEFORETRAPHOOK, NULL);
     if (*sigtr & ZSIG_FUNC) {
 	int osc = sfcontext;
 
@@ -912,6 +913,7 @@
 	zsfree(name);
     } else
 	execode(sigfn, 1, 0);
+    runhookdef(AFTERTRAPHOOK, NULL);
 
     if (trapreturn > 0)
 	trapret = trapreturn;
diff -ru ../z.old/Src/zsh.h Src/zsh.h
--- ../z.old/Src/zsh.h	Tue Mar 14 10:38:50 2000
+++ Src/zsh.h	Tue Mar 14 10:41:10 2000
@@ -1675,4 +1675,6 @@
 /* Hooks in core.                      */
 /***************************************/
 
-#define EXITHOOK (zshhooks + 0)
+#define EXITHOOK       (zshhooks + 0)
+#define BEFORETRAPHOOK (zshhooks + 1)
+#define AFTERTRAPHOOK  (zshhooks + 2)

--
Sven Wischnowsky                         wischnow@informatik.hu-berlin.de