Re: [Nexus] Fwd: Re: [MAHID] naming conventions

[Pete R. Jemian]

Suggest a slight change in the syntax to describe a link.

Seems that NeXus uses a different syntax to describe links
(look in these definitions: NXtas, NXtomo, and NXtomoproc
http://trac.nexusformat.org/definitions/browser/trunk/applications)

<link name="ef" target="/NXentry/NXinstrument/NXcrystal:analyzer/ef"/>

Looks like a space, while possible, might cause problems in this syntax.

That would suggest that we use a naming convention (the value of
the name attribute in either a group or the name of a specific variable) of:

[A-Za-z_][A-Za-z0-9_]*

and if we refer to an item by a named link, the syntax would
conform to this naming convention:

/[A-Za-z_][A-Za-z0-9_:]*)+

Also note that HDF4 has a name length limit of 64
characters (possible including NULL) and NeXus, to
be compatible, enforces this via the NX_MAXNAMELEN variable.

On 2/1/2010 9:28 AM, Pete R. Jemian wrote:
> What about referring to a target by both element tag (NXdetector) and
> name attribute ("mca 1")?
> Do we describe that syntax?
> perhaps: /NXentry/NXdetector['mca 1']
>
> On 2/1/2010 7:33 AM, freddie...@stfc.ac.uk wrote:
>> Yes - that is covered in the "validTargetName" definition, which is
>> currently "/[A-Za-z_][A-Za-z0-9_/]*" but could be a little tighter;
>> however as we need to check that targets point to valid location anyway
>> (and all final locations must be valid names) checking a target is a
>> valid path should be sufficient
>>
>> Freddie
>>

--
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Pete R. Jemian, Ph.D. <jem...@anl.gov>
Beam line Controls and Data Acquisition, Group Leader
Advanced Photon Source, Argonne National Laboratory
Argonne, IL 60439 630 - 252 - 3189
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Education is the one thing for which people
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