Re: [Arx-users] Comparing ArX and Arch and larch.

[Walter Landry]

Jarl Friis <address@hidden> wrote:
> Hi.
> 
> I have a few questions regarding arch, larch, and arX.
> 
> Are larch and arX compatible? i.e. can an larch client communicate
> with a arX server? how about the opposite?

Well, actually, there is no such thing as a larch or ArX server.
However, there are archives created by larch and ArX.  Except for some
old broken archives [1], ArX can read everything that larch has
created.  Larch might have problems with ArX archives, because ArX is
more permissive is what it allows you to commit into an archive.

But larch is the original shell implementation.  Tom Lord has since
made a C version, called TLA.  That has introduced another tagging
method, tagline.  It looks like a minor cleanup of the implicit
tagging method.  ArX does not support tagline at this time, though it
probably could be made to without too much effort.

> Is arch the specification/protocol, and larch and arX different
> implementations of the same spec/protocol?

More or less.  The specification isn't really written down, and Tom
and I have different ideas about how it should evolve.

> or are they completely different/incompatible.

They started from the same code base, so they are mostly compatible.
They are likely to diverge, because we have different ideas about how
to proceed.  I don't plan on any backwards incompatible changes in the
near future.

> In what way, if any, does arX take advantage of WebDAV/DeltaX?

It uses WebDAV as a way of reading remote files.  It does not use
DeltaX.  The differences between two revisions are already stored as a
patch, so ArX just gets the patch.

Walter

[1] This is related to automatic Changelogs.  Larch can't read them
either anymore.  If you didn't use them, there shouldn't be a problem.