| 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

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); 8 Years...; Attack Against Encrypted Linux Disks; Pushing Back On NSA At IETF; Summary of Experimental Ethics; Very Good Talk On Security, Snowden; Locusts are Grasshoppers!; Vagrant (OpenSuse and IDEs); Interesting Take On Mandela's Context; Haskell Cabal O(n^2) / O(n) Fix; How I Am 4; Chilean Charity Supporting Women; Doing SSH right; Festival of Urban Intervention; Neat Idea - Wormholes Provide Entanglement; And a Link....; Simple Encryption for Python 2.7; OpenSuse 13.1 Is Better!; Little Gain...; More Details on Technofull Damage; Palmrest Cracked Too....; Tecnofull (Lenovo Support) Is Fucking Useless; The Neuroscientist Who Discovered He Was a Psychopath; Interpolating Polynomials; Bottlehead Crack as Pre-amp; Ooops K702!; Bottlehead Crack, AKG K701; Breaking RC5 Without Rotation; Great post thank you; Big Balls of Mud; Phabricator - Tools for working together; Amazing Julia RC5 Code Parameterized By Word Size; Chi-Square Can Be Two-Sided; Why Do Brits Accept Surveillance?; Statistics Done Wrong; Mesas Trape from Bravo; European Report on Crypto Primitives and Protocols; Interesting Omissions; Oryx And Crake (Margaret Atwood); Music and Theory; My Arduino Programs; Elliptic Curve Crypto; Re: Licensing Interpreted Code; Licensing Interpreted Code; ASUS 1015E-DS03 OpenSuse 12.3 SSD; translating lettuce feature files into stub steps files; Re: translating lettuce feature files into stub steps files; A Tale of Two Psychiatrists; The Real Reason the Poor Go Without Bank Accounts; The Rational Choices of Crack Addicts; Forgot grouped

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

Generics + Dynamic = bad

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

Date: Fri, 3 Mar 2006 10:39:28 -0300 (CLST)

This Java ugliness turned up at work, but I don't see how to improve it.

We have are using a messaging system (Mule) that can make routing
decisions based on the message type (messages are POJOs).  Which is cool. 
We also have a need for a generic message:

public Message<E> {
  private E payload;
  public E getPayload() {return payload;}
  public void setPayload(E payoad) {this.paylod = payload;}
}

But Java erases generic types.  So this is sent to the messaging system as
a plain old Message.  Which means we can't route on the payload.  So we
end up writing a subclass:

public StringMessage exetends Message<String> {
  public String getString() {return getPayload();}
  public void setString(String string) {setPayload(string);}
}

Yuck.

Actually, writing that, I wonder what the point of the extra setters is. 
You already inherit a correctly typed getPaload and setPayload.  So it
seems to me that, apart from the slightly less informatitve method names,
the following is equivalent:

public StringMessage extends Message<String> {}

And that raises the question - why didn't Java do this to implement
generics?  It's what C++ templates do, and while there are problems,
they're not insurmountable, AFAIK.

Andrew

Talking of POJOs

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

Date: Fri, 3 Mar 2006 10:46:08 -0300 (CLST)

Etymology - http://www.martinfowler.com/bliki/POJO.html

Via Lambda / Category Theoreticians

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

Date: Tue, 14 Mar 2006 07:28:11 -0400 (CLT)

I forgot to add that the link above was found via Lambda, with the usual
"Java programmers are therfore idiots" snark.

Which is ironic give that the place is full of people who worship a theory
best introduced as:

  Well, you know, there's stuff, right, and you do shit to it and, well
  that gives you more stuff.

  [sounds of amusement/disbelief]

  No really, its cool, because the shit can be, like, anything...

Comment on this post