Wednesday 27 Jan 2010 by Orphi the AweKid.

Haskell makes use of a construct known as a monad. The obscurity of this term and the vast profusion of “monad tutorials” available on the Internet makes it seem as if monads are vitally important but highly complex.

But this is not actually the case. Monads are actually quite simple. It’s just that they are extremely abstract, so it’s kind of difficult to explain what they are in a simple way. It’s like trying to explain what a “number” is; it’s a simple enough idea, but hard to put into words.

Also, monads can be very useful, but that doesn’t mean you have to use them all the time. It’s not like all of Haskell revolves around monads. (Some people mistakenly get this idea.) Monads are just one kind of construct used in Haskell; they just happen to be unfamiliar to most people, so they get talked about a lot. Don’t take that as a sign of importance.

So what, finally, is a monad anyway? And why is there more than one type of monad?

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Friday 04 Dec 2009 by Orphi the AweKid.

It can be really frustrating trying to depend on things which are the product of somebody’s hobby.

If you’ve ever done it, you will recognise the truth of this statement. For example, I just tried to install Gtk2hs. Now therein lies a story…

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Thursday 03 Dec 2009 by Orphi the AweKid.

Disclaimer: I am a Haskell addict. My opinion is meaningless.

Haskell is a purely-functional language. It has non-strict evaluation semantics, an extended Milner-Hindley type system with automatic type inference, and monadic containment of side-effects.

One of the standard newbie questions is “what the heck is a monad?”, to which the standard answer is “a monad is just a monoid in the category of endofunctors, what’s the problem?”

Obviously, if you happen to be a professor of mathematics, this answer is entirely satisfactory. If, however, you’re just Java Programmer Dude, this probably doesn’t make a lot of sense. Now, I could sit here and explain what all these terms mean (they’re not nearly as complicated as they sound), but that’s not the point. The point is, Haskell is a language designed by mathematicians. You’re going to meet a lot of exotic technical terms while working with it. Don’t let that put you off.

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Wednesday 15 Jul 2009 by Orphi the AweKid.

As anybody vaguely aquainted with Haskell will know, Haskell has automatic type inference. That is, the compilers and interpretters can (usually) automatically detect what type everything has, so no hand-written type signatures are required. (Contrast this with, say, Pascal or C or Java where every procedure, function and variable must explicitly be given a type declaration.)

Just for giggles, I’m trying to implement this myself. And when you do this, you rapidly realise that while getting the basic framework to work is surprisingly easy, getting the whole thing to work properly is rather difficult.

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Tuesday 03 Mar 2009 by Orphi the AweKid.

Haskell is, in my humble opinion, the ultimate programming language. [Yes, I’m aware that at one time I said the same thing about Eiffel. And maybe some day I’ll find something that surpasses Haskell. But I doubt it…] Haskell is not perfect, however. There are a number of things I’d change about the language.

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Friday 26 Sep 2008 by Orphi the AweKid.

Preface

OK, so the muse has taken me. I want to write something. If somebody reads this, let me know what you think of my powers of exposition.

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Wednesday 28 May 2008 by Orphi the AweKid.

Ever since I signed up to the Haskell mailing list, I have noticed slight reliability issues. It’s possible to read the mailing list using Gmane, but to post you have to be signed up.

So I can read the list from Gmane or my inbox. But the two sources don’t always agree. Sometimes I post an email, and it appears on Gmane, but doesn’t appear in my inbox for a day or two. Sometimes messages from other people appear on Gmane and never arrive in my inbox. Sometimes I post a message, and it doesn’t appear anywhere for many hours. And so on.

In the last few days, I have discovered that every time I post a message to the mailing list, I get an automatic message that it is being held for moderation becuase this is a moderated list. I have no way of knowing whether all messages on the list are being moderated or just mine. The automatic message states that the message will either be posted or I will be notified of why it isn’t being posted, but I have now sent several emails which to this date have not been posted.

I’m beginning to wonder whether this is due to faulty technology or a deliberate campaign to get me to shut up…

(It’s probably worth noting that my ISP’s email system seems a little flakey at best, so that’s probably where the problem is. But I’m becomming paranoid now!)

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Wednesday 14 May 2008 by Orphi the AweKid.

Haskell is, without doubt, an obscure programming language. Recently it’s been trying to come out of the shadows, but still, it remains thoroughly niche. This is a real problem for anybody wanting to use the thing. Allow me to demonstrate…

Today I heard about Leksah, and IDE for Haskell. So I thought I’d give it a whirl.

Do you have any idea how difficult this turned out to be???

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