Hello Ivan, Thanks for bringing Graphviz to Haskell, and for your continuing dedication to making it more complete! I just tried Graphvis for the first time a few days ago. I regretted the absence of example code, especially as the API has been evolving, so that examples on the Web do not generally work without change. I see that the inclusion of QuickStart-style documentation is on your short-term list of milestones. I suppose an example program is not quite that, but it might help. Do you have something along these lines? Or, if not, if I managed to put something together which exercises a good cross-section of the features, do you think you could include it with the next release? I suppose there's a trade-off between ease of maintaining the code through releases, and feature coverage of the example(s)... I'm CC-ing haskell-cafe in case anyone reading already has some example code like this, which they'd be willing to donate? If possible, it ought to be small yet illustrate a lot of features. Kind Regards, Andrew On Thu, Apr 19, 2012 at 10:10 AM, Ivan Lazar Miljenovic wrote:

I should have pointed out that for most people, there should be minimal to no API change with this release; the only change I needed to make in my own code was that a type-class I had defined in Graphalyze was removed as it provided the impetus for the ToGraphID class mentioned below.

On 19 April 2012 22:52, Ivan Lazar Miljenovic wrote:

...

I'm hoping the second part of the version number isn't ominous, but I've just uploaded the latest release in my bindings for the Graphviz suite of graph visualisation tools.

The changes in this release are:

* Added support for the `osage` and `patchwork` visualisation tools,  available as of Graphviz-2.28.0.

* Updated attributes as of Graphviz-2.28.0:

   - `SVG` colors are now supported, and the support for different      colors has been revamped.

   - `overlap=false` is now equivalent to `overlap=prism` and the      `RemoveOverlaps` option has been removed.

   - `LabelScheme` and `Rotation` are new attributes for use with      `sfdp`.

   - `Scale` is a new attribute for use with `twopi`.

   - Add new italics, bold, underline, superscript and subscript      options for HTML-like labels.

   - `LHeight` and `LWidth` for getting the height and width of the      root graph and clusters.

* Updated attributes from the current development branch of Graphviz  (i.e. 2.29.*).  Please note that these will probably not work yet,  but are implemented now for future-proofing.

   - A new style for edges: `Tapered`.

   - `XLabel` allows you to specify labels external to a node or      edge.  `ForceLabels` allow you to specify that these should be      drawn even when they will cause overlaps.

   - `ImagePath` allows you to specify where to search for images.

   - HTML-like labels now support `ID` values as well as horizontal      and vertical rules.

   - `BgColor` and `FillColor` now take a list of colors: this allows      gradient fills for graphs, clusters and nodes.  The `Radial`      style and `GradientAngle` are also used for this purpose.

   - `FillColor` is now used by edges to set the color of any arrows.

   - [WebP](http://en.wikipedia.org/wiki/WebP) output support added.

* Other attribute changes:

   - Use a specified data type for the `Ordering` attribute rather      than an arbitrary `Text` value, and provide a documented wrapper      in `Data.GraphViz.Attributes`.

   - `Bb` has been renamed `BoundingBox`.

   - `ID` now only takes `EscString` (a type alias for `Text`) values      rather than arbitrary `Label`s.

   - The `Data.GraphViz.Attributes.HTML` module has had all values      re-named and is now meant to be imported qualified.  It is also      no longer re-exported from `Data.GraphViz.Attributes.Complete`.

* The `ToGraphID` class provides a common wrapper to help create  cluster identifiers, etc.

* Cabal's `Test-Suite` functionality is now used.  As part of this,  the `Data.GraphViz.Testing` module and sub-modules are no longer  exported by the library.

* The new `Benchmark` support in Cabal-1.14 is now used for the  benchmark script.

* Dropped support for base-3.

* The `Data.GraphViz.State` module is no longer exposed, as there's no  need for users to use it.

* Bugfixes:

   - Some corner cases in canonicalisation prevented it from being      idempotent.

   - The `TestParsing` script will no longer crash and refuse to      continue if an IO-based error (e.g. unable to successfully call      `dot`) occurs.

   - A typo was spotted by **Gabor Greif**.

-- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com http://IvanMiljenovic.wordpress.com

-- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com http://IvanMiljenovic.wordpress.com

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Alright, thank-you Ivan. I'm not yet using any standard library for my graphs, although no doubt I should, and FGL sounds like the obvious choice. Just hoping for a "tour de force" example of the layout and visualisation possibilities, preferably some Haskell code in the public domain that was guaranteed to work with the current version of the graphviz library, and could be used by newcomers as a springboard. Probably I'm being lazy, and should just start from scratch from the API. Thanks again for your efforts! -Andrew On Thu, Apr 19, 2012 at 6:04 PM, Ivan Lazar Miljenovic wrote:

On 20 April 2012 03:21, Ras Far wrote:

...

Hello Ivan,

Thanks for bringing Graphviz to Haskell, and for your continuing dedication to making it more complete!

I just tried Graphvis for the first time a few days ago.  I regretted the absence of example code, especially as the API has been evolving, so that examples on the Web do not generally work without change.

I see that the inclusion of QuickStart-style documentation is on your short-term list of milestones.  I suppose an example program is not quite that, but it might help.  Do you have something along these lines?  Or, if not, if I managed to put something together which exercises a good cross-section of the features, do you think you could include it with the next release?  I suppose there's a trade-off between ease of maintaining the code through releases, and feature coverage of the example(s)...

Well, one reason I haven't included anything like that is because I'm not sure what to write, or where to put it!

If you're using FGL graphs, you probably want [graphToDot]; otherwise, [graphElemsToDot] might do what you want (for which I've written an [example], which is also linked to from the [FAQ]).

[graphToDot]: http://hackage.haskell.org/packages/archive/graphviz/2999.13.0.1/doc/html/Da... [graphElemsToDot]: http://hackage.haskell.org/packages/archive/graphviz/2999.13.0.1/doc/html/Da... [tutorial](http://ivanmiljenovic.wordpress.com/2011/10/16/graphviz-in-vacuum/) [FAQ]: http://projects.haskell.org/graphviz/faq.html

-- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com http://IvanMiljenovic.wordpress.com