On Tue, Sep 08, 2009 at 10:39:00AM +0200, Mario 'BitKoenig' Holbe wrote:
> On Mon, Sep 07, 2009 at 08:56:31PM +0200, Julian Andres Klode wrote:
> > If there is a statement like 'DPkg::Post-Invoke:: "blah"' a new subitem
> > without a name is added to the configuration option DPkg::Post-Invoke.
> > The same applies to 'DPkg::Post-Invoke { "blah" }'. We create a new option
>
> Ah, I got it now.
> So,
> DPkg::Post-Invoke { "blah" };
> is equal to
> DPkg::Post-Invoke:: "blah";
> while
> DPkg::Post-Invoke:: { "blah" };
> would be equal to
> DPkg::Post-Invoke:::: "blah";
Yes, but its behavior is undefined.
>
> I guess it would be good to explain this in the manpage. Probably at the
> place which talks about the trailing ::.
As far as I can see, it only talks about command-line options, which do
not use curly braces at all.
>
> A few questions remain to me:
> 1. Shouldn't then the "list" term be removed from the manpage? Or is
> Foo::Bar { "foo"; "bar"; }
> the construct which is generally accepted to represent a "list"?
This is accepted, yes. You just add two options to "Foo::Bar" which
both have no name.
> 2. In my #503481 DPkg::Post-Invoke example, why does
> DPkg::Post-Invoke:: { "echo 99test3"; };
> get overwritten by
> DPkg::Post-Invoke:: { "echo 99test4"; };
> To my understanding, this should expand to
> DPkg::Post-Invoke { { "echo 99test3"; "echo 99test4"; }; };
I guess the problem is that you are first appending to the list, so
the situation is (in Python style code):
1. [["echo 99test3"]]
2. [["echo 99test3"], []]
3. [["echo 99test3"], ["echo 99test4"]]
The problem now is that the code loops to the last element of
DPkg::Post-Invoke:: and takes all commands below this
(e.g. "echo 99test4"). At least that's the impression I get
from reading code some time ago.
But all in all, the behavior of unnamed options below an unnamed
option (i.e. lists in lists) is undefined. I guess it would be
possible to check for cases where '::::' is specified and throw
an error.
> 3. Why does "echo 99test4" gets executed at all, it is not in the same
> scope as the "normal"/other DPkg::Post-Invoke commands.
No idea yet. I guess I should look at the code again.
--
Julian Andres Klode - Debian Developer, Ubuntu Member
See http://wiki.debian.org/JulianAndresKlode and http://jak-linux.org/.
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