05 June
2004

State Machines

Dave Roberts reflects upon the importance of state machines in computing and laments that programmers must reinvent them when needed for lack of language support. He's using Lisp macros to implement a state machine mini-language.

At least one language does have built in support for state machines. New in J 5.03 is a state machine primitive. From the J Dictionary:

x;:y implements a sequential machine (finite state machine, finite state automaton). x is the specification of a machine, including the state transition table, and y is the input. A sequential machine solves the problem of recognizing the "words" in the input. The machine starts in some initial state and processes the input one item at a time; given the current state and input item, the new state and output are determined by the state transition table. The machine then proceeds to process the next input item.

Though not a primitive, Lush includes a state machine library for manipulating grammars and graphs.


Posted by Steve at 18:15 | Comments (0) | Trackbacks (0)

Clearsilver

Clearsilver is an interesting web templating system that enforces strong separation of application logic and display format. It's written in C for speed and is language neutral with API's for C/C++, Python, Perl, and Java.


Posted by Steve at 06:36 | Comments (0) | Trackbacks (0)
03 June
2004

SpaceShipOne Launch Set

Burt Rutan's SpaceShipOne will make its first space launch attempt on 21 June 2004. If successful, this will be the first privately developed manned vehicle to reach space (100 km altitude).


Posted by Steve at 04:33 | Comments (0) | Trackbacks (0)
31 May
2004

More Snow and Another Fox

Yesterday evening it looked like the weather was starting to clear, but the wind picked up late last night and we woke to more snow, with periodic white outs and visibility down to about 100 meters. It began clearing about mid morning and we headed back toward Lyons. We stopped near the fox den to see if we could get a photo, but no such luck. We didn't see the kits, but did see an adult fox, though we didn't manage to get a clear shot at it.

We stopped in Longmont on the way home to walk around down town and have lunch. Not much was open, but the Pump House did serve a good meal.


Posted by Steve at 13:44 | Comments (0) | Trackbacks (0)
30 May
2004

All Corvettes Are Red

I finished reading All Corvettes Are Red which tells the story of the creation of the C5, the fifth generation Corvette. GM came close to killing it, and the book is as much about GM's corporate culture as it is the car. It is worth reading for both Corvette fans and anyone interested in new product development. The C5 is truly a great car, and it's interesting to see how a company that has often stumbled in recent years could bring it to market.

Red is perhaps the natural color for Corvettes, just as it is for Ferraris and other sports cars. My C5 was silver, but my Honda S2000 is red, as was my del Sol. If I get a C6 it might be red, but I think I might be ready for another silver car.


Posted by Steve at 21:30 | Comments (0) | Trackbacks (0)

Foxes in the Snow

Yesterday's snow flurries turned into a real snow storm today. We spent most of the day in the cozy log house reading and watching the snow fall. It slacked off in the afternoon and we went for a walk in the fresh snow. We spied a pair of fox kits playing outside their den.


Posted by Steve at 19:30 | Comments (0) | Trackbacks (0)
29 May
2004

St. Mary's Glacier

We're spending the Memorial Day weekend at the St. Mary's Glacier Bed & Breakfast Lodge. It's beautiful here, if a little remote. This log house is a twenty minute drive north of Idaho Springs at an elevation of 10,500 feet and the glacier's 300 feet higher. You ford a (very small) stream to get here.

It's Springtime in the Rockies, with snow flurries off and on all day, interspersed with sunny periods. It only accumulated in sheltered areas until dusk, when the flurries became a steady snowfall. We drove down to Idaho Springs to browse around the shops, have lunch, and pick up some groceries to bring back to St. Mary's. We cooked a pizza for dinner, then went for a walk in the snow.


Posted by Steve at 21:00 | Comments (0) | Trackbacks (0)
27 May
2004

More on Lush

Not quite the full power of Lisp.

In my earlier comments about Lush I said that it had the full power of Lisp. This is certainly true of the Lush interpreter, but not for compiled Lush. For the Lush compiler to be effective, you must add declarations and avoid recursion. Still, it's close enough for many applications. Even compiled, it provides most of the power of Lisp with much of the power of APL.


Posted by Steve at 05:09 | Comments (0) | Trackbacks (0)
26 May
2004

Aerospace Ships

Disruptive Technology

When I first heard of a corporate space initiative involving airships, I assumed it involved launching rockets from balloons, but it turns out to be something more ambitious. JP Aerospace plans to take a V shaped airship to the edge of space for the DOD in the next few weeks. They hope to eventually reach orbit with an airship driven by an ion drive.


Posted by Steve at 20:18 | Comments (0) | Trackbacks (0)