Ordering of versions

[Glyn Normington]

Thanks Mark - that's helpful. One other thing: are qualifiers treated as strings from an ordering perspective?

Regards,
Glyn

On 8 Nov 2011, at 22:54, mark.reinhold at oracle.com wrote:

> 2011/11/7 2:10 -0800, gnormington at vmware.com:
>> The requirements document description of versioning ([1]) says:
>> 
>> "Version strings must be totally ordered but otherwise the module
>> system must not impose any particular structure or semantics upon
>> them."
>> 
>> Dalibor Topic's presentation on Jigsaw at EclipseCon Europe gave some
>> interesting examples of versions supported by Jigsaw, but it wasn't
>> clear how a total ordering could be defined that preserved the total
>> ordering of multiple version conventions.
>> 
>> For example, what is the order of the following versions, where "-" is
>> taken to delimit a qualifier: 1.2-3,1.2.1-3, 1.2.3?
> 
> Exactly the order you gave: 1.2-3 < 1.2.1-3 < 1.2.3
> 
> Jigsaw presently treats the last '-' as introducing a qualifier or branch
> version.  When comparing two version strings the qualifiers are tested
> only if the segments preceding them are identical.
> 
> This design is imperfect.  If nothing else, a direct mapping to Debian
> package versions violates the Debian versioning policy [1].
> 
> - Mark
> 
> 
> [1] http://www.debian.org/doc/debian-policy/ch-controlfields.html#s-f-Version