[Kde-hardware-devel] Solid device action predicates

[Ozan Çağlayan]

Kevin Ottens wrote On 08-07-2009 03:23:
>
> It exactly acts like an OR operator, but the binary one so foo.bar == 'X|Y' 
> means that foo.bar should have both X and Y.
>   

So looking at k3b's one which checks for a blank medium:

[[StorageVolume.ignored == false AND OpticalDisc.blank == true ] AND
OpticalDisc.discType == 'CdRecordable|CdRewritable']

It expects both CdRecordable and CdRewritable for the discType property,
right? But a recordable cd has only the first one and a rewriteable has
the second. So it seems like a misusage of that operator?

Or another example:

$ solid-hardware details /org/freedesktop/Hal/devices/acpi_CPU0
udi = '/org/freedesktop/Hal/devices/acpi_CPU0'
  parent = '/org/freedesktop/Hal/devices/computer'  (string)
  vendor = ''  (string)
  product = 'AMD Athlon(tm) 64 X2 Dual Core Processor 4800+'  (string)
  Processor.number = 0  (0x0)  (int)
  Processor.maxSpeed = '0'  (string)
  Processor.canChangeFrequency = false  (bool)
  Processor.instructionSets = 'IntelMmx|IntelSse|IntelSse2|Amd3DNow' 
(0x27)  (flag)

Say that I'm trying to filter processors having only IntelMmx
instruction set. According to your reply, using & makes sense:

$ solid-hardware query "Processor.instructionSets & 'IntelMmx'"
udi = '/org/freedesktop/Hal/devices/acpi_CPU0'
udi = '/org/freedesktop/Hal/devices/acpi_CPU1'

Seems working but try a stupid one:

$ solid-hardware query "Processor.instructionSets & 'foobar'"
udi = '/org/freedesktop/Hal/devices/acpi_CPU0'
udi = '/org/freedesktop/Hal/devices/acpi_CPU1'

It matches too!

And now with the '|' :

$ solid-hardware query "Processor.instructionSets == 'IntelMmx|IntelSse'"
$ solid-hardware query "Processor.instructionSets ==
'IntelMmx|IntelSse|IntelSse2'"
$ solid-hardware query "Processor.instructionSets ==
'IntelMmx|IntelSse|IntelSse2|Amd3DNow'"
udi = '/org/freedesktop/Hal/devices/acpi_CPU0'
udi = '/org/freedesktop/Hal/devices/acpi_CPU1'

It only matches if I check again the whole flag set. So what's the point
in here? It really behaves like I'm checking the instructionSets
property against a string which contains "X|Y|Z|W" having | characters
in it. No?


I'm really confused about the syntax/semantics of the predicates.

Thanks!
Ozan Caglayan