| Andrew Cooke | Contents | Latest | RSS | Twitter | Previous | Next

C[omp]ute

Welcome to my blog, which was once a mailing list of the same name and is still generated by mail. Please reply via the "comment" links.

Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

Personal Projects

Lepl parser for Python.

Colorless Green.

Photography around Santiago.

SVG experiment.

Professional Portfolio

Calibration of seismometers.

Data access via web services.

Cache rewrite.

Extending OpenSSH.

Last 100 entries

I Want To Be A Redneck!; Reverse Racism; The Lost Art Of Nomography; IBM Data Center (Photo); Interesting Account Of Gamma Hack; The Most Interesting Audiophile In The World; How did the first world war actually end?; Ky - Restaurant Santiago; The Black Dork Lives!; The UN Requires Unaninmous Decisions; LPIR - Steganography in Practice; How I Am 6; Clear Explanation of Verizon / Level 3 / Netflix; Teenage Girls; Formalising NSA Attacks; Switching Brakes (Tektro Hydraulic); Naim NAP 100 (Power Amp); AKG 550 First Impressions; Facebook manipulates emotions (no really); Map Reduce "No Longer Used" At Google; Removing RAID metadata; New Bike (Good Bike Shop, Santiago Chile); Removing APE Tags in Linux; Compiling Python 3.0 With GCC 4.8; Maven is Amazing; Generating Docs from a GitHub Wiki; Modular Shelves; Bash Best Practices; Good Emergency Gasfiter (Santiago, Chile); Readings in Recent Architecture; Roger Casement; Integrated Information Theory (Or Not); Possibly undefined macro AC_ENABLE_SHARED; Update on Charges; Sunburst Visualisation; Spectral Embeddings (Distances -> Coordinates); Introduction to Causality; Filtering To Help Colour-Blindness; ASUS 1015E-DS02 Too; Ready Player One; Writing Clear, Fast Julia Code; List of LatAm Novels; Running (for women); Building a Jenkins Plugin and a Jar (for Command Line use); Headphone Test Recordings; Causal Consistency; The Quest for Randomness; Chat Wars; Real-life Financial Co Without ACID Database...; Flexible Muscle-Based Locomotion for Bipedal Creatures; SQL Performance Explained; The Little Manual of API Design; Multiple Word Sizes; CRC - Next Steps; FizzBuzz; Update on CRCs; Decent Links / Discussion Community; Automated Reasoning About LLVM Optimizations and Undefined Behavior; A Painless Guide To CRC Error Detection Algorithms; Tests in Julia; Dave Eggers: what's so funny about peace, love and Starship?; Cello - High Level C Programming; autoreconf needs tar; Will Self Goes To Heathrow; Top 5 BioInformatics Papers; Vasovagal Response; Good Food in Vina; Chilean Drug Criminals Use Subsitution Cipher; Adrenaline; Stiglitz on the Impact of Technology; Why Not; How I Am 5; Lenovo X240 OpenSuse 13.1; NSA and GCHQ - Psychological Trolls; Finite Fields in Julia (Defining Your Own Number Type); Julian Assange; Starting Qemu on OpenSuse; Noisy GAs/TMs; Venezuela; Reinstalling GRUB with EFI; Instructions For Disabling KDE Indexing; Evolving Speakers; Changing Salt Size in Simple Crypt 3.0.0; Logarithmic Map (Moved); More Info; Words Found in Voynich Manuscript; An Inventory Of 3D Space-Filling Curves; Foxes Using Magnetic Fields To Hunt; 5 Rounds RC5 No Rotation; JP Morgan and Madoff; Ori - Secure, Distributed File System; Physical Unclonable Functions (PUFs); Prejudice on Reddit; Recursion OK; Optimizing Julia Code; Cash Handouts in Brazil; Couple Nice Music Videos; It Also Works!; Adaptive Plaintext; It Works!; RC5 Without Rotation (2)

© 2006-2013 Andrew Cooke (site) / post authors (content).

Tiny Workflow Language

From: "andrew cooke" <andrew@...>

Date: Wed, 8 Mar 2006 08:54:18 -0300 (CLST)

I think I may finally have understood this "business process" thing at
work today.  If the following still makes sense in the cold light of
tomorrow morning then I will implement it at work.

tiny.package-info: "A tiny workflow"
tiny.Annotated: class annotation:DomXml payload:Object
tiny.Test: interface DomXml->boolean
tiny.Sink: interface Annotated->void
tiny.Flow: interface extends Test, Sink
tiny.Process: class Filter Flow Object->void
tiny.sink.package-info: "Simple sinks for error handling"
tiny.sink.Throw: class<Sink Class<Exception>
tiny.sink.Silent: class<Sink
tiny.sink.LogMsg: class<Sink String (or XPath?)
tiny.sink.Log: class<Sink String (or XPath?)
tiny.test.package-info: "Tests using XML annotation"
tiny.test.Always: class<Test
tiny.test.Never: class<Test
tiny.test.XPath: class<Test XPathExpression
tiny.flow.package-info: "Build Flow-based sequences"
tiny.flow.All: class<Flow Test List<Flow>
tiny.flow.First: class<Flow Test List<Flow> Sink
tiny.flow.Pair: class<Flow Test Sink
tiny.input.package-info: "Conversion to the internal format"
tiny.input.Normalize: interface Object->boolean Object->Annotated
tiny.input.Filter: class List<Normalize> Sink
tiny.input.Name: class<Normalize String

Notes
- the Sinks in First and Filter are exception handlers
- assembly via constructors or setters (Spring)
- All + First give basic logic, sequencing, etc
- Support for single elements/arrays as well as lists, for easy config

The basic idea is that you define a Process that accepts an Object and
calls an appropriate Sink.  The input Object is processed by a matching
Filter to give an Annotated which combines the original Object with an Xml
annotation.  Subsequent processing decisions are based on the annotation,
which is passed to various Tests.

Realising that Flow was the only necessary component for constructing more
complex logic (ie that Test could be Always if the test were irrelevant)
was critical in simplifying the types.  Without that, classes in the flow
package had to manage various combinations of Test and Sink.

I think the set of operations above is sufficient for quite a range of
tasks.  It'll be interesting to see if (1) this is anything like the right
idea and (2) if so, how it compares to something like BEPL.

The most obvious things that are missing at the moment are:
- the ability to modify the annotation (state)
- sophisticated error handling

An example in Java might be:

  new Process(
    new Filter(
      new IngestRequestNormalize(),
      new Throw("Cannot normalize")),
    new First(
      new Flow[] {
        new TestSinkPair(
          new XPath("a/b/c/Mosaic"),
          new MosaicIngest())
        new TestSinkPair(
          new XPath("p/q/r/Echelle"),
          new EchelleIngest())},
      new Throw("Cannot ingest")))

That's a process that converts incoming data if it's an IngestRequest.
Converted data are then tested to see if they are from a Mosaic and, if
so, ingested.  If not, a test is made for Echelle data.  If that fails
too, an exception is raised.

In Spring it would be similar, but with properties.  I think it will look
pretty good.

Now I need to sleep.  Want to run tomorrow before work.

Andrew

Comment on this post