I think I'd like to do some Smalltalk (or Squeak) development sometime.  Just for myself.  It would be good for me -- like an artist going to a retreat and setting aside all notions of practicality.  I know I'll never work in Squeak professionally.  That's why it would be like saying to yourself, "In this now, purity of expression is all that matters.  Tomorrow, I will worry about making something I can sell.  Tomorrow I will design so the mediocre masses that follow me cannot corrupt it.  Today, I will work for the joy I find in the work."

Earlier this year, Reading Buses switched over to using bio-ethanol on its No. 17 route, and now, whenever one of these buses passes, you get a distinct whiff of vinegar in the air.  Presumably this a result of incomplete combustion of the ethanol to acetic acid.  Or maybe the ethanol they use is already partly oxidized by bacterial action?  (Photo by Arriva436.)

Market Place, Reading, UK.  Photo taken this morning (2008-08-16).  The dark clouds were threatening rain, but none fell.  The building on the right really is that irregular shape.

One style of functional programming is based purely on recursive equations.  Such equations are easy to explain, and adequate for any computational purpose, but hard to use well as programs get bigger and more complicated.  In a sense, recursive equations are the ‘assembly language’ of functional programming, and direct recursion the goto. As computer scientists discovered in the 1960s with structured programming, it is better to identify common patterns of use of such too-powerful tools, and capture these patterns as new constructions and abstractions.  In functional programming, in contrast to imperative programming, we can often express the new constructions as higher-order operations within the language, whereas the move from unstructured to structured programming entailed the development of new languages.

Well, I think the GADT type definition syntax is the syntax data type definitions should have had from the start. Too bad we didn't realize it 15 years ago.

I agree! In my experience teaching Haskell, the current syntax is a bit confusing for newbies, and for years I've been telling students, "It really means this: ..." and then I write out a syntax more like GADT's.

I spent today in west London and got a little confused when finding my way around.  I have just discovered why:  Google Maps, which I used to plan my route beforehand, incorrectly shows North Kensington about 3km southeast from where it should be (in the same place that it --correctly-- shows South Kensington).  Fortunately the pocket street map I took with me did not contain this error.

A few days ago I noticed some of these on a pile of wood-chips in the woods between Farnborough North and Frimley stations.  I also noticed that they seemed to change form between the mornings and the afternoons.  I have tentatively identified them as Coprinus lagopus, a type of ink-cap mushroom.  In the mornings their stems are straight (up to 12cm long) and their caps neat little inverted translucent grey umbrellas (up to 5cm across), as shown above.  By the late afternoon, the stems have drooped and the caps are ragged, shrivelled and blackened, as shown below.

However, by the afternoon, the next day's mushrooms are already thrusting their heads up:

A hoverfly of the species Episyrphus balteatus (A fairly common species characterized by the two narrow black bands on its abdomen).  Photo taken in Reading University grounds, Reading, UK, on 2008-07-26.  One of the first photos I took with my present camera was of one of these; see here.

Harlequin ladybirds (Harmonia axyridis) vary a lot in appearance from red spot on black forms, through black spot on red, to black spot on yellow.  These are all the same species and, as shown here, interbreed quite freely.  Photo taken in Reading University grounds, Reading, UK, on 2008-07-26. The ladybirds that I photographed last November here also appear to be harlequins.