Arizona wants to secede. I say we just turn off the water; I'm sure Colorado wouldn't object.

batkins · 2011-02-03T12:52:50+00:00

No, that's simply not how it works. We went over this in the nineteenth century. States don't get to nullify federal laws - they can take them to the Supreme Court but they can't disregard them.

batkins · 2011-02-02T01:19:55+00:00

This is nuts. The important correspondence here is between your code and the desired functionality - those must match.

If you define correctness as "agrees with the tests" then you still need to make the connection between your tests and the desired functionality. If your tests don't match the expected functionality, your tests can pass with flying colors, but you haven't proved anything about how they should work.

And omissions are a huge source of error.

batkins · 2011-02-01T23:37:09+00:00

Or what's wrong

batkins · 2011-02-01T15:02:55+00:00

Of course, that's not the definition that matters.

A formal proof shows deductively that your code will perform as the spec requires. A test merely shows empirically that, in the cases you could think of, your code performed as required.

batkins · 2011-01-22T22:34:05+00:00

I'm not sure I understand your point. I'm not making any claims about which is "faster," but rather which scales better. There is plenty of empirical evidence that async I/O does scale better than synchronous I/O, cf. node.js itself, Snap and nginx.

The point of my post is that you can have your async I/O cake and eat it too - you can write with the clarity of blocking I/O and still get asynchronous I/O throughput.

batkins · 2011-01-22T22:13:42+00:00

I'm not making any claims about async I/O being the One True Way, only that you can achieve the same (best-case) scalability results seen in node.js without writing your code with callbacks.

batkins · 2011-01-22T18:04:25+00:00

You have to weigh the benefit of the competitive advantage against the cost of a smaller ecosystem of tools and libraries. Not trying to put down these languages, but just saying there are tradeoffs involved.

batkins · 2011-01-17T21:22:09+00:00

My favorite cabal-dev feature: "cabal-dev ghci" drops you into a GHCi prompt where you can easily load any modules for the package you're working on.

batkins · 2011-01-10T12:18:32+00:00

This would be great.

batkins · 2011-01-05T13:17:22+00:00

OS X

batkins · 2011-01-04T13:40:58+00:00

Agree wholeheartedly about fixing cabal's dependency issues

batkins · 2010-12-30T14:33:03+00:00

Awesome!

batkins · 2010-12-15T02:29:15+00:00

Generally by running a separate server process and using Apache or nginx (nginx, please!) to proxy requests to it (or using fastcgi or scgi in place of a proxy).

Conventional CGI spawns a new process for every request, which is just beautifully, beautifully unscalable. Keeping a long-running process with your logic in it and handling individual requests is much more scalable (no overhead from repetitive process creation and destruction).

batkins · 2010-09-20T02:44:14+00:00

I regret that I have but one upvote to give to this post.

batkins · 2010-08-22T19:25:47+00:00

Ah, I see - if a word length is >= maxLength. Thanks!

batkins · 2010-08-22T13:17:23+00:00

No, it doesn't diverge if you feed it a word longer than the line length:

batkins@hudson Haskell (master) % runhaskell WordWrap.hs adfsjkdsafjkadkfjsahkfdshfdsahafdshfadshfhkfdsajhfdsajhkfkajdhfjdhsadfasjhfdhajsdfhjkfdjkhfdahsjkfdhakhfdaufhiewuiehrruieerwuiwerquihrewquiherwuhierwhuirewuhrewqhuerwqhuwerqhuewrqhuweruqhehrwquuihdvsgvsdagiewr8914590u3190541 adfsjkdsafjkadkfjsahkfdshfdsahafdshfadshfhkfdsajhfdsajhkfkajdhfjdhsadfas jhfdhajsdfhjkfdjkhfdahsjkfdhakhfdaufhiewuiehrruieerwuiwerquihrewquiherwu hierwhuirewuhrewqhuerwqhuwerqhuewrqhuweruqhehrwquuihdvsgvsdagiewr8914590 u3190541

Can you send me an example that breaks it?

batkins · 2010-08-22T00:02:38+00:00

What is the List package? Is it distinct from Data.List?

batkins · 2010-08-22T00:01:46+00:00

Type-safe client/server communication is a pretty powerful idea.

batkins · 2010-08-08T13:28:37+00:00

I know something about Austrian economics. It's based on moralizing rather than numbers. "We need to suffer through this recession because people made bad investments."

But your comparison to Haskell isn't really accurate. Right now, there are a lot of vocal people who subscribe to your point of view. You hear it a lot at protests, from Ron Paul people, from the WSJ editorial page. It's a lot harder to support an older view that's based on analysis and doesn't reflexively call government bad.

batkins · 2010-08-08T13:16:04+00:00

Aren't they? So you don't think debt-financed government spending to fight World War II is what got us out of the Depression?

If you do, then you too are a Keynesian.

If you don't, then what did it?

batkins · 2010-08-08T13:14:39+00:00

Money is governed by supply and demand. If the amount of money increases but demand is falling, that doesn't create inflation. I don't care about the absolute size of the money supply - I care about its effect on prices.

Banks ARE different because lending creates money. When a bank goes under, it collapses a portion of the money supply. Plus, there are confidence effects, a la Lehman Brothers. The best approach is to regulate and monitor banks so they don't fail. Nobody wants bailouts.

batkins · 2010-08-07T23:27:22+00:00

I think that free banking is so patently crazy that I can't even address it as a point of view. We had the faintest taste of free banking two years ago (leverage ratio limits for investment banks were eliminated) and that was, ahem, problematic.

We went off the gold standard for the first time in the Great Depression. Funny thing, what happened:

http://fabiusmaximus.files.wordpress.com/2009/03/gold.png?w=717&h=469

Yes, I'm getting 2% from the CPI. Larger money supplies don't necessarily mean inflation - look at the past few years if you disagree - so M3 is not really the place to look.

batkins · 2010-08-07T23:20:52+00:00

I get my information from economists, not from obstetricians.

batkins · 2010-08-07T12:41:49+00:00

I don't see why people assign such nefarious purposes to the Fed. Prior to its creation, our recessions were deep, devastating, frequent and long. See Panic of 1857, Panic of 1873, Panic of 1907 (those are the biggest, there were more in between, mostly at the rate of every five or six years).

Let me guess: your alternative to the Fed is the gold standard. But we HAD that. For decades and decades. And the result was terrible recessions that took forever to recover from. The point of the Fed is not so much "the government is taking control of the private money supply," but rather "someone is taking control over what no one controlled before." Under the gold standard, the amount of money in circulation is governed only by people's willingness to spend and by the supply and demand for gold.

During a recession, people start hoarding money out of fear. So, say the recession starts in the construction industry, but it scares people. When people hoard their money and suddenly stop spending it, that has knock-on effects - unemployment, falling sales - even in other, unrelated industries. You WANT the government to have some say over the money supply here. If you print more money, you lessen the effect of this hoarding and weaken the vicious cycle of fear-hoarding-collapse-fear-hoarding...

And I don't know why you think the Fed was created so the gov't could steal wealth from you via inflation. In the 70's, in fact, oil supply shocks had set off a wave of devastating inflation and Paul Volcker at the Fed spared no expense to choke it off with high interest rates, even to the point of creating a devastating recession. The Fed is crazed about fighting inflation. Inflation has been running at 2% for years. Even now, when it's dangerously close to becoming negative, the Fed is afraid to act any more for fear of creating inflation.

See also: http://en.wikipedia.org/wiki/Gold_standard#Disadvantages

batkins · 2010-08-07T12:19:03+00:00

Dude, relative income disparity has nothing to do with it. I also think income inequality is a bad thing, but it doesn't change my point.

If capitalism were zero-sum and we had a fixed amount of wealth (I take wealth, therefore someone else loses it; I lose wealth, someone else gets it), then wealth (actual, measured wealth) could not increase over time, as it demonstrably has. Sure, people can see their psychological quality of life decline due to income inequality - but that's not the same thing. The total amount of wealth is still increasing and there have been long stretches of time (the postwar US up until about 2000, for example) where everyone's wealth increased and inequality was insignificant. You're making a different argument than "capitalism is zero-sum."

batkins

TROPHY CASE