Additionally permit non-negative integers as key components. A
dictionary's keys must either be all integers or none. If all keys
are integers, convert the dictionary to a list. The set of keys must
be [0,N].
Examples:
* list.1=goner,list.0=null,list.1=eins,list.2=zwei
is equivalent to JSON [ "null", "eins", "zwei" ]
* a.b.c=1,a.b.0=2
is inconsistent: a.b.c clashes with a.b.0
* list.0=null,list.2=eins,list.2=zwei
has a hole: list.1 is missing
Similar design flaw as for objects: there is no way to denote an empty
list. While interpreting "key absent" as empty list seems natural
(removing a list member from the input string works when there are
multiple ones, so why not when there's just one), it doesn't work:
"key absent" already means "optional list absent", which isn't the
same as "empty list present".
Update the keyval object visitor to use this a.0 syntax in error
messages rather than the usual a[0].
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488317230-26248-25-git-send-email-armbru@redhat.com>
[Off-by-one fix squashed in, as per Kevin's review]
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Until now, key components are separated by '.'. This leaves little
room for evolving the syntax, and is incompatible with the __RFQDN_
prefix convention for downstream extensions.
Since key components will be commonly used as QAPI member names by the
QObject input visitor, we can just as well borrow the QAPI naming
rules here: letters, digits, hyphen and period starting with a letter,
with an optional __RFQDN_ prefix for downstream extensions.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-20-git-send-email-armbru@redhat.com>
keyval_parse() parses KEY=VALUE,... into a QDict. Works like
qemu_opts_parse(), except:
* Returns a QDict instead of a QemuOpts (d'oh).
* Supports nesting, unlike QemuOpts: a KEY is split into key
fragments at '.' (dotted key convention; the block layer does
something similar on top of QemuOpts). The key fragments are QDict
keys, and the last one's value is updated to VALUE.
* Each key fragment may be up to 127 bytes long. qemu_opts_parse()
limits the entire key to 127 bytes.
* Overlong key fragments are rejected. qemu_opts_parse() silently
truncates them.
* Empty key fragments are rejected. qemu_opts_parse() happily
accepts empty keys.
* It does not store the returned value. qemu_opts_parse() stores it
in the QemuOptsList.
* It does not treat parameter "id" specially. qemu_opts_parse()
ignores all but the first "id", and fails when its value isn't
id_wellformed(), or duplicate (a QemuOpts with the same ID is
already stored). It also screws up when a value contains ",id=".
* Implied value is not supported. qemu_opts_parse() desugars "foo" to
"foo=on", and "nofoo" to "foo=off".
* An implied key's value can't be empty, and can't contain ','.
I intend to grow this into a saner replacement for QemuOpts. It'll
take time, though.
Note: keyval_parse() provides no way to do lists, and its key syntax
is incompatible with the __RFQDN_ prefix convention for downstream
extensions, because it blindly splits at '.', even in __RFQDN_. Both
issues will be addressed later in the series.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488317230-26248-4-git-send-email-armbru@redhat.com>
