I'm still sort of a beginner with Haskell, but ere are my thoughts. In the sense you mean it, yes Haskell could be considered inflexible because it makes it easier to implement a functional design and harder to implement an imperative design. But if I were to go back to Java now, I would find it very inflexible because it makes it very difficult to functional design, and very easy to do imperative design. I would miss features like functors, monads, and lazy evaluation. On 18 May 2010 01:22, aditya siram wrote:

Haskell is considered by many as an inflexible language [1] . I describe a flexible language as one that supports any design you want (even a bad one) - if you can think it, you can code it and run it (bugs and all).

I share this opinion about Haskell but pursue it because I feel that one day it will open up and let me think more about the problem and less about how to get GHC to approve it.

So I guess the question to you practitioners is: Would you agree that it is a rigid language as describe in the link below, or is that just an illusion that goes away with experience?

-deech

[1] http://therighttool.hammerprinciple.com/statements/this-language-has-a-very-... _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Aditya, I have been programming in imperative languages for 20+ years and Haskell for about 2 years, and I've written a lot of it. I've never found Haskell restricting. Twice I have decided that a dynamic type was needed, and in many cases I've used object-oriented approaches in Haskell where it makes sense. This is actually fairy often. One example is a web widgets library where each widget had different 'render', 'parse', etc methods. Doing OO in Haskell isn't hard at all, in my opinion. You just use a data structure of functions. If you want it to have mutable state, you use an IORef (but it really isn't necessary). It's more typing than usual Haskell, but it still beats Java. Python would be more succinct than both. I've also written things very imperatively in IO, and found I could do anything I liked. I can think of some very small parts of programs where it might have been a little easier in Java or Python, but not by much, and Haskell's other advantages generally offset it. On occasions I've realized that the design wasn't going to work, and I needed to get some data from A to B. In other languages, you can use a global variable or singleton (same thing). In Haskell it means a bit of re-design. But the thing is, it's so easy to refactor in Haskell, that the extra work doesn't matter much. Your code is already modular at every level, so it's easy to move things around. When your code never gets a chance to get messy, and the type system doesn't let you break anything that previously worked, refactoring becomes a pleasure instead of a chore. So Haskell's inflexibility actually gives you the ability to rearrange your program effortlessly. That is, you get a lot in return. I could probably add that Haskell's inflexibility is determined by the types you give things. You can restrict yourself as much or as little as you like, but Haskell allows you to restrict yourself a lot more than other languages do. Steve On 18/05/10 12:22, aditya siram wrote:

Haskell is considered by many as an inflexible language [1] . I describe a flexible language as one that supports any design you want (even a bad one) - if you can think it, you can code it and run it (bugs and all).

I share this opinion about Haskell but pursue it because I feel that one day it will open up and let me think more about the problem and less about how to get GHC to approve it.

So I guess the question to you practitioners is: Would you agree that it is a rigid language as describe in the link below, or is that just an illusion that goes away with experience?

-deech

[1] http://therighttool.hammerprinciple.com/statements/this-language-has-a-very-... _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Am 18.05.10 02:22, aditya siram wrote:

Haskell is considered by many as an inflexible language [1] . I describe a flexible language as one that supports any design you want (even a bad one) - if you can think it, you can code it and run it (bugs and all).

I share this opinion about Haskell but pursue it because I feel that one day it will open up and let me think more about the problem and less about how to get GHC to approve it.

The key point of the "rigidity" is that it forces you to think about the problem. If GHC does not approve my code, then it's either a typo manifesting as a type error, or it's a much deeper problem that highlights that I didn't think enough about it. And with a strict typing discipline, something else begins to happen: "Still, as usual, the types were a remarkable aid to writing the code: when we finally agreed on the types presented above, the code almost wrote itself." Ramsey, Dias, Peyton Jones. Hoopl: A Modular, Reusable Library for Dataflow Analysis and Transformation. http://tinyurl.com/hoopl-dataflow [pdf] Regards, Heinrich Apfelmus -- http://apfelmus.nfshost.com