Re: Completion problems.

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

Tanaka Akira wrote:

> In article <199908021058.MAA12713@beta.informatik.hu-berlin.de>,
>   Sven Wischnowsky <wischnow@informatik.hu-berlin.de> writes:
> 
> > That's wrong, too. Again, this is a problem with the recently changed
> > quoting behaviour. The prefix is reported in quoted form and appended
> > and prepended to IPREFIX/ISUFFIX -- which will be quoted again when it 
> > is inserted.
> 
> Thanks. It is fixed.  But such a unquoting/re-quoting seems bit
> problematic with variables.
> 
> Z(3):akr@is27e1u11% Src/zsh -f
> is27e1u11% fpath=($PWD/Completion/*(/)); autoload -U compinit; compinit -D; compdef _tst tst
> is27e1u11% _tst () { compset -P '*/'; compadd tst }
> is27e1u11% var=val
> is27e1u11% tst $var/<TAB>
> 
> Then, the last line is changed to:
> 
> is27e1u11% tst \$var/tst 

Ugh. Hm. Since compgen doesn't quote I{PRE,SUF}FIX, compadd shouldn't
do it, either (especially since the strings given with -[iI] aren't
quoted).
This patch tries to make the code use I*FIX as is in all cases.

(...and I still have to look into this multi-quoting thing for
compset-q/compctl-h, sigh.)

> I think automatic unquoting/re-quoting is dangerous.
> 
> Since the completion code works on quoted form and unquoted form is
> only interesting to usual completers, definitely the conversion
> between these forms is required. But it is sometimes very difficult or
> even impossible.
> 
> In following examples, unquoted forms are not known until runtime.
> 
> % if some-complex-command; then var=xxx; else var=yyy; fi; tst $var/<TAB>
> % tst $(some-complex-command)/<TAB>
> 
> So, I think that it is dangerous decision to embed the quoting stuff
> into the completion code.

(I'm not sure what you mean by `embed'.) The problem, err, one of the
problems with quoting and completion is that we have to call the lexer 
to get at the words from the line and then we have to live with what
the lexer gives us -- which is quoted. But for special contexts (such
as parameter expansions) we need to unquote (and probably tokenize) it 
to find out what's going on. Then we have to decide what we give to
the user, which currently is (or should be) the form from the
line. This is also important when it comes to comparing or matching
such strings, of course, and the globcomplete-behaviour comes into
play, too (where we even want the stuff from the line in tokenized
form).
We already had too much trouble with quoting in completion, so I'm
reluctant to change a state which has worked for some time.

I see two ways to go: 1) completely change the completion code to
report strings in unquoted form or 2) add a parameter expansion
modifier which does something like the opposite of `:q'.
Unfortunately, 1) is extremly hard and error-prone.

> I think that it is right way to separate the quoting stuff to builtin
> or variable expansion.

I don't understand you here, sorry. Oh, after reading further: do you
suggest something like the `opposite-of-:q'-thing or a builtin to work 
on quoted/unquoted strings?

> Also, I don't like re-quoting such as:
> 
> % tst a'#'/<TAB>
> ->
> % tst a\#/...
> 
> My expectation to completion is simply inserting something into cursor
> position. So re-quoting surprise me.  If the quoting stuff is
> separated, customizing these behaviours may be easier.

We can't really separate the quoting stuff, see above.

Also: changing a'#' to a\# is intentional and was discussed -- see
6400 and follow-ups (especially 6460 for this example). Even if
completion just inserts something new at the cursor position, this is
not necessarily the case. With completion functions like _path_files
and with match specs using `*'-patterns new stuff can be inserted
anywhere in the word. To retain the single quotes the completion code
would have to keep track of the original positions and would have to
calculate the new positions for every single or double quote inside
the word. This is extremly difficult, expensive (i.e. slow), and at
least I wouldn't implement it (if anyone else is interested: try to
find out how the completion code now handles completion inside braces
-- you would have to do something similar, but not only for two
places, but for a whole list of positions).

> Also, making the quoting stuff usable from completers is useful for
> checking the array words. For example, currentry, following does not
> work because contents of words are quoted form and $words[2] is
> "'-d'".
> 
> % cvs '-d' <TAB>
> 
> If _cvs can unquote the word safely, _cvs can determin options more
> precisely.

Yes, see above.

Bye
 Sven

diff -u os/Zle/compctl.c Src/Zle/compctl.c
--- os/Zle/compctl.c	Mon Aug  2 14:38:03 1999
+++ Src/Zle/compctl.c	Wed Aug  4 10:49:58 1999
@@ -1888,7 +1888,7 @@
     char *tmp, sav = compprefix[l];
 
     compprefix[l] = '\0';
-    tmp = tricat(compiprefix, rembslash(compprefix), "");
+    tmp = tricat(compiprefix, compprefix, "");
     zsfree(compiprefix);
     compiprefix = tmp;
     compprefix[l] = sav;
@@ -1903,7 +1903,7 @@
     char *tmp, sav;
 
     l = strlen(compsuffix) - l;
-    tmp = tricat(rembslash(compsuffix + l), compisuffix, "");
+    tmp = tricat(compsuffix + l, compisuffix, "");
     zsfree(compisuffix);
     compisuffix = tmp;
     sav = compsuffix[l];
@@ -2126,9 +2126,11 @@
     case CVT_RANGEPAT:
 	tokenize(sa);
 	sa = rembslash(sa);
+	remnulargs(sa);
 	if (sb) {
 	    tokenize(sb);
 	    sb = rembslash(sb);
+	    remnulargs(sb);
 	}
 	break;
     case CVT_PRENUM:
@@ -2144,6 +2146,7 @@
 	    na = -1;
 	tokenize(sa);
 	sa = rembslash(sa);
+	remnulargs(sa);
 	break;
     }
     return !do_comp_vars(test, na, sa, nb, sb, 1);
diff -u os/Zle/zle_tricky.c Src/Zle/zle_tricky.c
--- os/Zle/zle_tricky.c	Mon Aug  2 14:38:04 1999
+++ Src/Zle/zle_tricky.c	Wed Aug  4 11:00:31 1999
@@ -3811,13 +3811,8 @@
 	    /* Get the contents of the completion variables if we have
 	     * to perform matching. */
 	    if (dat->aflags & CAF_MATCH) {
-		if (dat->aflags & CAF_QUOTE) {
-		    lipre = dupstring(compiprefix);
-		    lisuf = dupstring(compisuffix);
-		} else {
-		    lipre = quotename(compiprefix, NULL);
-		    lisuf = quotename(compisuffix, NULL);
-		}
+		lipre = dupstring(compiprefix);
+		lisuf = dupstring(compisuffix);
 		lpre = dupstring(compprefix);
 		lsuf = dupstring(compsuffix);
 		llpl = strlen(lpre);
@@ -5030,8 +5025,6 @@
 	remnulargs(p);
 	ctokenize(s);
 	remnulargs(s);
-	ctokenize(ip);
-	remnulargs(ip);
     }
     lp = strlen(p);
     ls = strlen(s);

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