Hal, What is the syntactic sugar that you are lacking with arrays? Also, do loops matter if they can be emulated with recursion? Thanks, Joel On Dec 24, 2005, at 12:46 AM, Hal Daume III wrote:

That said, I use O'Caml for all of my non-Perl coding. Why? Because I need lots of arrays and though Haskell does support them, the lack of syntactic sugar makes it very inconvenient. Second, lack of loop support, which I can live without. Finally, it's slower. I would forgive the last (it can be made faster if you use unboxed arrays and so on) if the first two were fixed.

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On Sat, Dec 24, 2005 at 03:11:06PM +0000, Daniel Carrera wrote:

Tomasz Zielonka wrote:

...

There are many differences (Haskell on the left): - pure / impure

Let's see if I understand this one. Haskell and OCaml both treat functions as first class objects, including the ability to pass functions as arguments or return functions. But OCaml allows you to change the value of a variable and that's what makes it impure. Yes?

More precisely, it allows to change/access mutable variables as part of expression evaluation.

Does this mean that it's harder to prove an OCaml program correct? Or that you have to be careful to not accidentally change the value of variables?

Both, actually. Best regards Tomasz -- I am searching for a programmer who is good at least in some of [Haskell, ML, C++, Linux, FreeBSD, math] for work in Warsaw, Poland

From: Daniel Carrera To: Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] Haskell vs OCaml Date: Sat, 24 Dec 2005 20:07:00 +0000

Tomasz Zielonka wrote:

...

When it comes to Haskell, speed is mostly an implementation issue.

I just took another look at this. By "implementation issue" do you mean the person who implements the compiler or the program being compiled? If the latter... other emails here suggest that writing an efficient Haskell program is a difficult task :-(

I've found that Haskell is pretty good in implementing recursive algorithms. Problem cames when one want's to implement non recursive algorithm by terms of recursion as Haskell does not support loops. Perhaps if we can get loops, situation will improve, but then that wouldn't be functional style. Try for example to implement recursive calculation of matrix determinant in some classic imperative language and in Haskell on large matrix, or compare performance of recursive descent parser implemented in Haskell and language which does not handles recursion so well as Haskell. Other problem is that Haskell data is lazy and optimised for size rather then speed. One have to use non lazy structures in order to compete with imperative languages speed combined with non recursive algo's. Difficulty came when one has to utilize Haskell advantages and reduce much as possible disadvantages. After all you can peek and poke over Ptr's same as in C which will give you speed as in C :) (I've tried that works well as I used to peek/poke:) Greetings, Bane. _________________________________________________________________ FREE pop-up blocking with the new MSN Toolbar - get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/

From: Lennart Augustsson To: Branimir Maksimovic CC: daniel.carrera@zmsl.com, Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] Haskell vs OCaml Date: Sun, 25 Dec 2005 10:25:44 +0100

Branimir Maksimovic wrote:

...

I've found that Haskell is pretty good in implementing recursive algorithms. Problem cames when one want's to implement non recursive algorithm by terms of recursion as Haskell does not support loops. Perhaps if we can get loops, situation will improve, but then that wouldn't be functional style.

Could you give an example of a loop you find awkward in Haskell?

Well I want simple loop for(int i =0;i<10;++i)doSomething(i); in haskell that would be for begin end f | begin /= end = do {f begin ; for (begin+1) end f} | otherwise = return ()

I've often found that you can just define a control construct in Haskell when needed (e.g., some kind of loop).

I don't know how to do that. Greetings, Bane. _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

From: Matt Collins To: "Branimir Maksimovic" CC: Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] Haskell vs OCaml Date: Sun, 25 Dec 2005 21:42:35 +1100

Perhaps something like

for :: Int -> Int -> (Int -> IO ()) -> IO () for begin end f = sequence_ [ f i | i <- [begin..end] ]

*Main> for 1 10 print 1 2 3 4 5 6 7 8 9 10

Great! what are constrains on [begin..end] could they be some type which supports (+) , but not Int. I need this cause perhaps there is possibility to impleemnt STL like algo's in Haskell and that would be even better then C++, cause Haskell has more powerfull parametric polimorfism and C++ badly needs lambda's. That's why STL is somewhat ugly, but lib tried to employ functional style programming over sequences and is not bad, though in C++ one has to make lot of auxiliary classes because of lack of lambda's. If I can make Iterator generic class and specialize for different containers that would be it. Last question is: Does creation of list of functions humpers performance? Greetings, Bane.

On 25/12/2005, at 9:35 PM, Branimir Maksimovic wrote:

...

...

From: Lennart Augustsson To: Branimir Maksimovic CC: daniel.carrera@zmsl.com, Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] Haskell vs OCaml Date: Sun, 25 Dec 2005 10:25:44 +0100

Branimir Maksimovic wrote:

...

I've found that Haskell is pretty good in implementing recursive algorithms. Problem cames when one want's to implement non recursive algorithm by terms of recursion as Haskell does not support loops. Perhaps if we can get loops, situation will improve, but then that wouldn't be functional style.

Could you give an example of a loop you find awkward in Haskell?

Well I want simple loop for(int i =0;i<10;++i)doSomething(i); in haskell that would be for begin end f | begin /= end = do {f begin ; for (begin+1) end f} | otherwise = return ()

...

I've often found that you can just define a control construct in Haskell when needed (e.g., some kind of loop).

I don't know how to do that.

Greetings, Bane.

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On 12/25/05, Branimir Maksimovic wrote:

...

From: Lennart Augustsson To: Branimir Maksimovic CC: daniel.carrera@zmsl.com, Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] Haskell vs OCaml Date: Sun, 25 Dec 2005 10:25:44 +0100

Branimir Maksimovic wrote:

...

I've found that Haskell is pretty good in implementing recursive algorithms. Problem cames when one want's to implement non recursive algorithm by terms of recursion as Haskell does not support loops. Perhaps if we can get loops, situation will improve, but then that wouldn't be functional style.

Could you give an example of a loop you find awkward in Haskell?

Well I want simple loop for(int i =0;i<10;++i)doSomething(i); in haskell that would be for begin end f | begin /= end = do {f begin ; for (begin+1) end f} | otherwise = return ()

Or just 'mapM_ doSomething [1..10]' (:

...

I've often found that you can just define a control construct in Haskell when needed (e.g., some kind of loop).

I don't know how to do that.

Greetings, Bane.

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On Sun, Dec 25, 2005 at 11:09:51AM +0000, Branimir Maksimovic wrote:

...

Or just 'mapM_ doSomething [1..10]' (:

Neet! However would it be more efficient for, say, 1 million iterations? Anyway I have to look for map functions. I'm learning step by step from tutorials :)

I remember I was impressed when I checked what GHC made of such code. No lists, no allocations, just a tight loop :-) BTW, in my library of small Haskell utilities I have for_ l f = mapM_ f l for l f = mapM f l and I use it like this for_ [1..10] $ \i -> do do something with i It's just because there's often more code in f than in l. When I don't have my handy little library, I use a more baroque syntax: (`mapM_` [1..10]) $ \i -> do do something with i Now that I think about it, this variant would be nicer: flip mapM_ [1..10] $ \i -> do do something with i Best regards Tomasz -- I am searching for a programmer who is good at least in some of [Haskell, ML, C++, Linux, FreeBSD, math] for work in Warsaw, Poland

Branimir Maksimovic wrote:

...

Could you give an example of a loop you find awkward in Haskell?

Well I want simple loop for(int i =0;i<10;++i)doSomething(i);

mapM_ doSomething [0..9] -- Glynn Clements