Re: Enum'Image (Was: Improving Ada's image)

["Dr. Adrian Wrigley" <amtw@linuxchip.demon.co.uk.uk.uk>]

On Wed, 23 Jun 2004 15:29:23 -0500, Randy Brukardt wrote:
...
> In any case, Text_IO.Enumeration_IO does let you set the case of the
> output. (It could use a Mixed_Case option, though). Remember that 'image
> is for Q&D output, not the fancy stuff (something we all forget often).

I fear that none of the proposed solutions would be without
heavy (perhaps reasonably justified) criticism from some quarters.

A Mixed_Case option in Enumeration_IO seems pretty harmless though.
I guess we have to wait another ten years for a chance of this
to appear though :(  (Ada 201Z) (I presume it can't be sneaked
in to '0Y :()

Most of the suggestions fail to get the right case for enumeration output
from generic functions, where the type has been passed as a parameter.
Possibiliies that get this right are rejected as having the
potential to break existing code.

Saying that 'Image is for Q&D programming might be true, but ignores
the fact that that's what programmers often want.  Ada is sometimes
shunned because of the presumed costs of meeting the language discipline.
In my experience, however, Ada is well suited to Q&D programming,
because the integrity and clarity of the interfaces, and exceptionally
low debugging time.

Having to define functions that simply convert each enumeration
into the corresponding string, then passing them as generic
parameters really grates against my aesthetic sense, particularly
since it just seems to be working around a language mis-feature.

Curiously, when I first came across the 'Image function attribute
(actually in VHDL, IIRC), I automatically assumed you could
provide your own (as others here have suggesed).  I was quickly
disappointed to find out just how limited it was.

Here's a few enumerations that really need verbatim output of case:
Ada, COBOL, Pascal, PostScript - languages
kWh, Joules, kCal  - energy units
ms, MS             - milliseconds? megasiemens?
Mbps, MBPS, mbps   - megabits per second? millibytes per second?
nVIDIA, ATI, Intel, AMD  - technology companies

I guess there are much more important things for Ada users to
be worried about though...
-- 
Adrian