[cups.general] Why not "recommend" PPDs in the NickName?

[Michael Sweet]

Johannes Meixner wrote:
> Hello,
> 
> On Jan 26 08:30 Michael Sweet wrote (shortened):
> 
>> Johannes Meixner wrote:
>>> ...
>>> Personally I prefer probabilities instead of percentage values
>>> (where 1 means "perfect" and 0 means "useless") and perhaps
>>> optionally additional weights with default weight = 1.
>> Multiply by 100 to get percentages, which can be represented as
>> integers...
> 
> No.
> A probability is in the range [0,1].
> In contrast 120% is an allowed percentage value.

Not as we have defined it (0% to 100% supported; 120% supported
makes no sense!)

> But meanwhile I think probabilities are wrong because
> of their limited range.
> A driver which is considered right now to produce perfect
> printout quality would have the probability 1 regarding quality
> but how should we do the ranking for a new driver which produces
> even better quality (it cannot have a probability of 1.2).

Will the same printer suddenly inherit new features and capabilities?

In my experience (13 years doing printer software, more years using
printers) manufacturers never add features to existing models, they
always create a new model name/number (often a variation of the
original) which requires a new/separate driver.

 > ...
> Then also percentages become misleading because a driver
> which is considered right now to produce perfect printout
> quality would have 100% regarding quality but when we set

WE ARE NOT MEASURING QUALITY!

Quality is subjective and can change over time.  Instead, we
want to recommend a driver that a) supports the most features/
capabilities of a printer and b) provides the fastest printing
for a particular use case.

> ...
> Additionally I think we should allow negative integer values
> to rate also annoying stuff like
>   *DriverRestriction/Works only on 32-bit hardware: "-3"
>   *DriverStability/Craches often for unknown reason: "-5"

Unstable drivers should never be shipped/provided by a distro.
If a user does an install, they will find out how stable the
driver is pretty quickly and remove it if the driver doesn't
work.

Drivers not compatible with a particular architecture will not
be installed and so will not be a choice for the user.

> For example this driver may produce the really best quality
> at high speed (therefore topmost ranking values for quality
> and speed) but at the moment it is in alpha state and therefore
> some other ranking values should be there to get a correct
> overall ranking value for a PPD which uses this driver.
> When it is in a stable state which works also on 64-bit hardware,
> the above entries can be removed from the PPD.

Don't ship alpha-quality software that doesn't work on all of your
supported platforms!

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products           mike at easysw dot com
Internet Printing and Document Software          http://www.easysw.com