Implementing XProc, V

Volume 10, Issue 55; 30 May 2007; last modified 08 Oct 2010

Part the fifth, in which we get the green light!

This essay is part of a series of essays about implementing an XProc processor. XProc: An XML Pipeline Language is a W3C specification for specifying a sequence of operations to be performed on one or more XML documents. I'm implementing XProc as the specification progresses. Elsewhere you'll find background about pipelines and other essays about XProc.

I'm happy (delighted, excited, relieved, …) to report that my request to open source the XProc implementation that I've been working on has been approved.

There's a bit of administrivia still to do: making sure that appropriate copyright statements appear in all the source files, bundling it with the correct license files (GPLv2 and CDDL), writing some release notes, etc.

My implementation has also drifted a bit away from the current public specification, partly in anticipation of, and partly to test the feasibility of, changes that the working group is discussing.

I think the best plan is to bring my code in line with the decisions we make for the next public working draft and release my implementation when that's published.

And I should fix some of the funkiness in the way nested loops behave too…


Great news Norm!. It's good to hear that progress is being made. One question though, why worry too much about spec-conformance when the spec is still a moving target? Release early, release often right?

Also do you know if anybody else from the working-group is planning on is working on or planning to release an implementation?

I'm not sure if I know of any actively developing implementations.

—Posted by Chris Scott on 31 May 2007 @ 05:31 UTC #

I'm not going to worry about it too much, but right now I've implemented things that aren't in the current spec and may not be accepted by the WG for the next spec, so I think it would be just too confusing.

I think several other WG members are working on implementations and I've heard of two others by non-WG members so I think it's looking good.

—Posted by Norman Walsh on 31 May 2007 @ 06:21 UTC #