Haskell vs OCaml

Haskell vs OCaml

[circ ular]

What are the advantages/disadvantages when comparing OCaml to Haskell?

Re: [Caml-list] Haskell vs OCaml

[Brian Hurt]

circ ular wrote:

>What are the advantages/disadvantages when comparing OCaml to Haskell?
>
>  
>

The biggest disadvantage of comparing Ocaml to Haskell would have to be 
causing a long, pointless flamewar.  Offhand, I can't think of an upside.

Brian

Re: [Caml-list] Haskell vs OCaml

[Jon Harrop]

On Wednesday 13 August 2008 13:48:45 circ ular wrote:
> What are the advantages/disadvantages when comparing OCaml to Haskell?

Techically, predictable performance, high performance on x64, tools like 
camlp4 and language features including records, functors, polymorphic 
variants and structurally-typed objects are probably the main advantages of 
OCaml over Haskell.

Non-technically, OCaml has more well-tested libraries, more practical books 
(e.g. my own), more high-profile open source projects (e.g. FFTW has millions 
of users):

http://ocamlnews.blogspot.com/2007/12/top-10-most-popular-ocaml-programs.html
http://haskell-news.blogspot.com/2008/01/top-10-most-popular-haskell-programs.html

and is much more widely used in industry. There are far more 
practically-minded people in the OCaml community and that is reflected in the 
much larger number of commercial products that use OCaml.

Tangentially, OCaml has a successful relative in F# whereas Haskell's close 
relatives are extinct.

I did extensive research on all of the most popular functional languages last 
year, including Haskell. In case you are trying to do something similar, I'll 
warn you that almost all of the examples of Haskell's use in industry are 
fakes, e.g. companies that have no products, companies that have one product 
that never used Haskell, companies that happen to have two Haskell advocates 
working for them out of 150 developers, companies where one employee once did 
a preliminary Haskell program but nothing since and, finally, plain old spam 
where companies that have never had anything to do with Haskell have hijacked 
the Haskell site to advertise on-line only to be hailed as a "real world" 
example of Haskell in industry by its proponents. I was rather baffled when I 
discovered this and have never seen behaviour like it.

Haskell also has some advantages over OCaml, of course, but you should 
probably ask the Haskell community to explain them. I consider them all to be 
untested because nobody has ever done anything significant using Haskell 
AFAIK.

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/products/?e

Re: [Caml-list] Haskell vs OCaml

[David Thomas]

--- On Wed, 8/13/08, Jon Harrop <jon@ffconsultancy.com> wrote:

> I consider them all to be untested because nobody has ever done anything 
> significant using Haskell AFAIK.


Besides the window manager I'm currently using... :-P


      

Re: [Caml-list] Haskell vs OCaml

[Erik de Castro Lopo]

David Thomas wrote:

> --- On Wed, 8/13/08, Jon Harrop <jon@ffconsultancy.com> wrote:
> > I consider them all to be untested because nobody has ever done anything 
> > significant using Haskell AFAIK.
> 
> 
> Besides the window manager I'm currently using... :-P

And Darcs the distributed revision control system.

Erik
-- 
-----------------------------------------------------------------
Erik de Castro Lopo
-----------------------------------------------------------------
"Do I do everything in C++ and teach a course in advanced swearing?"
-- David Beazley at IPC8, on choosing a language for teaching

Re: [Caml-list] Haskell vs OCaml

[Paolo Donadeo]

> And Darcs the distributed revision control system.

Erik, Darcs is so slow, buggy and broken by design (I speak for direct
experience) that even the GHC team decided to switch to GIT or
Mercurial, see [1] and [2].

Consider this: three years ago I decided to study a functional
language and I had to decide between OCaml and Haskell. In that
period, for other reasons, I was searching for a new SCM to replace
CVS and I extensively tested Darcs.

Darcs was so broken that I decided for OCaml when I realized it was
written in Haskell.

So Darcs, IMHO, is definitively not "anything significant".


[1] http://www.reddit.com/comments/6v2nl/ghc_project_switches_to_git/
[2] https://lopsa.org/node/1656


-- 
Ing. Paolo Donadeo
Studio Associato 4Sigma
Website: http://www.4sigma.it
Email: p.donadeo@4sigma.it
~
~
:wq

Re: [Caml-list] Haskell vs OCaml

[blue storm]

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So it seems the debate went on anyway. I had written something, but when
just before posting i saw Brian Hurt's post, and decided not to. It now
seems i was wrong, and actually (when reading the others) my post seems
quite balanced after all.

I'm not saying that the other posters are biased in any way. But i have the
point of view of someone trying to learn a language "for fun" and in order
to discover interesting features or novel point of views. It seems Haskell
do much better in that context that in the "use it to do something useful in
the cruel world" context used so far.

So here is my original post :

I'm afraid your question is a bit too general (and it seems strange to ask
that on the mailing-list of one of the projects, while asking for a balanced
answer).

The main differences are :
OCaml is impure (imperative features in the language), Haskell is pure.
OCaml is strict, Haskell is lazy.
Ocaml has modules, Haskell has type classes.

If you're coming from the imperative land, OCaml is, in my opinion, easier
to learn.
It is also a good choice to begin with OCaml because everything you learn
with the OCaml basics can be reused for learning Haskell (the converse is
also true, but then you have to learn lazy evaluation first, wich is a
non-trivial shift, and is vastly less used in OCaml).
Haskell is certainly worth the effort, but my personal opinion is that
learning OCaml first is a good idea. Moreover, for "real world" application,
you may prefer OCaml over Haskell.

The syntax are different, but not so much (before learning haskell, i could
generally understand the purpose of tiny haskell sources). I have heard some
people say they prefer the Haskell syntax, but this is more a matter of
taste (and not very relevant if you want to learn something from the
language semantics). Both have their ugly sides.

Idiomatic OCaml implementations tend to produce more efficient than
Idiomatic Haskell implementations (but Haskell compilers are getting better
and better everyday (for Haskell performances to be good, compilers have to
do lots of clever and not so simple optimizations), and Haskell is faster
than most (scripting) languages used these days anyway).

The Haskell standard library is bigger than the Ocaml one, but this is
probably not an advantage for beginners (because this means more time spent
in browsing the doc, while playing with the language and reimplementing
functions yourself is much more interesting). Haskell program thus tends to
be more terse and "higher-level" (because of reusing a lot of higher-order
combinators in the stdlib): OCaml is also very expressive, but the
simplicity of the stdlib tends to keep people on simpler things.

To the advanced programmer, both languages have interesting advanced
features to offer. Haskell tends to specialize in sophisticated type system
features, whereas OCaml has an interesting object system, and polymorphic
variants. Both languages have very interesting derivatives, specific
languages intended to explore a specific area (concurrency, metaprogramming,
etc...).

Camlp4 is a flexible and powerful Ocaml preprocessor. Haskell has some tools
in that direction, that i have never used (so i'm mostly guessing here), but
they seem to be even less supported and used inside the community.

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Re: [Caml-list] Haskell vs OCaml

[Jon Harrop]

On Thursday 14 August 2008 03:46:10 David Thomas wrote:
> --- On Wed, 8/13/08, Jon Harrop <jon@ffconsultancy.com> wrote:
> > I consider them all to be untested because nobody has ever done anything
> > significant using Haskell AFAIK.
>
> Besides the window manager I'm currently using... :-P

Interestingly, the number of registered installs of XMonad has increased a lot 
from only 95 in January to 542 now. However, that is still orders of 
magnitude fewer than the most popular open source software written in OCaml:

Debian and Ubuntu registered installs
-------------------------------------
184,574: FFTW (14,298 lines of OCaml)
 12,866: Unison (23,993 lines of OCaml)
  7,286: MLDonkey (171,332 lines of OCaml)
  4,365: Darcs (3,939 lines of Haskell)
  4,066: FreeTennis (7,419 lines of OCaml)
  4,057: Planets (3,296 lines of OCaml)
  3,465: HPodder (2,225 lines of Haskell)
  2,965: LEdit (2,048 lines of OCaml)
  2,822: Hevea (11,596 lines of OCaml)
  2,657: Polygen (1,331 lines of OCaml)

So:

. 8/10 of the top ten most popular OCaml/Haskell open source projects on 
Debian and Ubuntu were written in OCaml and not Haskell.

. 221,293 installs of popular OCaml software compared to only 7,830 of 
Haskell.

. 235,312 lines of well-tested OCaml code compared to only 6,164 lines of 
well-tested Haskell code.

Some of the Haskell projects (e.g. pugs and srcinst) have even *decreased* 
in popularity over the past 7 months. Indeed, Darcs was only being used to a 
significant extent by the Haskell community and the GHC developers are now 
giving up on it themselves citing awful performance as one of the main 
reasons:

  http://hackage.haskell.org/trac/ghc/wiki/DarcsEvaluation

Note their own benchmark results:

  Annotate: Darcs is 50x slower than Git.
  Clone: Darcs is 49x slower than Git.

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/products/?e

Re: [Caml-list] Haskell vs OCaml

[David Mitchell]

Thanks - nice summary

Dave M.

On 14/08/2008, blue storm <bluestorm.dylc@gmail.com> wrote:
> So it seems the debate went on anyway. I had written something, but when
> just before posting i saw Brian Hurt's post, and decided not to. It now
> seems i was wrong, and actually (when reading the others) my post seems
> quite balanced after all.
>
> I'm not saying that the other posters are biased in any way. But i have the
> point of view of someone trying to learn a language "for fun" and in order
> to discover interesting features or novel point of views. It seems Haskell
> do much better in that context that in the "use it to do something useful in
> the cruel world" context used so far.
>
> So here is my original post :
>
> I'm afraid your question is a bit too general (and it seems strange to ask
> that on the mailing-list of one of the projects, while asking for a balanced
> answer).
>
> The main differences are :
> OCaml is impure (imperative features in the language), Haskell is pure.
>  OCaml is strict, Haskell is lazy.
> Ocaml has modules, Haskell has type classes.
>
> If you're coming from the imperative land, OCaml is, in my opinion, easier
> to learn.
> It is also a good choice to begin with OCaml because everything you learn
> with the OCaml basics can be reused for learning Haskell (the converse is
> also true, but then you have to learn lazy evaluation first, wich is a
> non-trivial shift, and is vastly less used in OCaml).
>  Haskell is certainly worth the effort, but my personal opinion is that
> learning OCaml first is a good idea. Moreover, for "real world" application,
> you may prefer OCaml over Haskell.
>
> The syntax are different, but not so much (before learning haskell, i could
> generally understand the purpose of tiny haskell sources). I have heard some
> people say they prefer the Haskell syntax, but this is more a matter of
> taste (and not very relevant if you want to learn something from the
> language semantics). Both have their ugly sides.
>
> Idiomatic OCaml implementations tend to produce more efficient than
> Idiomatic Haskell implementations (but Haskell compilers are getting better
> and better everyday (for Haskell performances to be good, compilers have to
> do lots of clever and not so simple optimizations), and Haskell is faster
> than most (scripting) languages used these days anyway).
>
> The Haskell standard library is bigger than the Ocaml one, but this is
> probably not an advantage for beginners (because this means more time spent
> in browsing the doc, while playing with the language and reimplementing
> functions yourself is much more interesting). Haskell program thus tends to
> be more terse and "higher-level" (because of reusing a lot of higher-order
> combinators in the stdlib): OCaml is also very expressive, but the
> simplicity of the stdlib tends to keep people on simpler things.
>
> To the advanced programmer, both languages have interesting advanced
> features to offer. Haskell tends to specialize in sophisticated type system
> features, whereas OCaml has an interesting object system, and polymorphic
> variants. Both languages have very interesting derivatives, specific
> languages intended to explore a specific area (concurrency, metaprogramming,
> etc...).
>
> Camlp4 is a flexible and powerful Ocaml preprocessor. Haskell has some tools
> in that direction, that i have never used (so i'm mostly guessing here), but
> they seem to be even less supported and used inside the community.
>
> _______________________________________________
>  Caml-list mailing list. Subscription management:
>  http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list
>  Archives: http://caml.inria.fr
>  Beginner's list:
> http://groups.yahoo.com/group/ocaml_beginners
>  Bug reports: http://caml.inria.fr/bin/caml-bugs
>
>

Re: [Caml-list] Haskell vs OCaml

[Peng Zang]

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On Thursday 14 August 2008 07:50:43 am blue storm wrote:
> The main differences are :
> OCaml is impure (imperative features in the language), Haskell is pure.
> OCaml is strict, Haskell is lazy.
> Ocaml has modules, Haskell has type classes.

I would restate the last as:

  OCaml has an object system, Haskell has type classes.


In Haskell you can write a function that takes anything that is "showable" (a 
type class) and print it out.  The sig would be something like (I'm mixing 
OCaml and Haskell syntax here, but hopefully the point is still clear):

  Showable 'a => 'a -> unit

You can't quite do that with modules/functors.  However with objects you can 
write a function that takes a showable and executes it.  It's sig would look 
like this:

  showable -> unit

where

  class type showable = object
    method print : unit -> unit
    ...
  end


As to Haskell vs. OCaml, they are both great languages.  Haskell is more 
researchy and experimental (although with Haskell Prime they are making a big 
push to make it more friendly to industrial uses).  This is great because you 
get some really cool stuff.  This is also bad because all the cool stuff is 
hard to understand and sometimes you-just-want-to-get-stuff-done.  OCaml is 
great for that and for one other thing that I think few people point out.  
OCaml supports a variety of programming styles: OO, imperative and 
functional.  This means it's easy for anyone to pick up and use.  If you have 
collaborators, OCaml projects have an easier learning curve.  Anyone can feel 
more or less at home using OCaml in a week.  In contrast, Haskell has quite a 
steep initial learning curve (eg. you need to learn monads before you can 
write any interesting real-world application) which can be a big barrier to 
potential collaborators.

Also the ability to switch styles often lets you write faster.  For some 
problems, I just think in one style versus another.  It just comes more 
easily to me in a functional style sometimes, and an OO style other times.  
OCaml let's you write however you think about it.  Haskell makes you think 
about it in *the haskell* way.  Sometimes this is good because it forces you 
to do certain things.  Othertimes it just gets in your way.


Peng
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Re: [Caml-list] Haskell vs OCaml

[Jon Harrop]

On Thursday 14 August 2008 12:50:43 blue storm wrote:
> It is also a good choice to begin with OCaml because everything you learn
> with the OCaml basics can be reused for learning Haskell (the converse is
> also true, but then you have to learn lazy evaluation first, wich is a
> non-trivial shift, and is vastly less used in OCaml).

Monads and zippers?

> The syntax are different, but not so much (before learning haskell, i could
> generally understand the purpose of tiny haskell sources). I have heard
> some people say they prefer the Haskell syntax, but this is more a matter
> of taste (and not very relevant if you want to learn something from the
> language semantics). Both have their ugly sides.

That reminds me: you can run the same OCaml code in the top-level, in the 
bytecode interpreter and through the native code compiler.

> Idiomatic OCaml implementations tend to produce more efficient than
> Idiomatic Haskell implementations (but Haskell compilers are getting better
> and better everyday (for Haskell performances to be good, compilers have to
> do lots of clever and not so simple optimizations),

Even if Haskell's performance is improved it will remain unpredictable and, 
consequently, it will continue to be impossible to optimize non-trivial 
Haskell programs.

> and Haskell is faster than most (scripting) languages used these days
> anyway). 

Despite being written in Python, Mercurial is orders of magnitude faster than 
Darcs.

> The Haskell standard library is bigger than the Ocaml one,

Does the Haskell stdlib provide a database interface, md5 checksums, 
marshalling, pretty printing, lexer generator, graphics library, regular 
expressions, unix interface and weak references?

> Haskell program thus tends to
> be more terse and "higher-level" (because of reusing a lot of higher-order
> combinators in the stdlib): OCaml is also very expressive, but the
> simplicity of the stdlib tends to keep people on simpler things.

I'm not sure what you mean by "simplicity of the [OCaml] stdlib tends to keep 
people on simpler things" but there is certainly far more non-trivial 
software written in OCaml than Haskell, both open source and commercial.

> Camlp4 is a flexible and powerful Ocaml preprocessor...

And an extensible general-purpose parser generator that is higher-level than 
Parsec. Camlp4 rocks!

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/products/?e

Re: [Caml-list] Haskell vs OCaml

[Peng Zang]

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On Thursday 14 August 2008 09:28:34 am Peng Zang wrote:
> OCaml let's you write however you think about it.  Haskell makes you think
> about it in *the haskell* way.  Sometimes this is good because it forces
> you to do certain things.  Othertimes it just gets in your way.
>
>
> Peng


Haha, I have some free time.  So, let me explain more about why sometimes it's 
good that Haskell makes you do things in a certain way.

One is that Haskell forces your program into two parts.  Parts that contain 
side-effects (in monads) and the part that is pure.  This is great because 
the compiler can now do some optimizations not available when you don't know 
if your code is pure.  This is also good because side-effects can be 
confusing and difficult to maintain over time.  By putting all the side 
effects in a box, you can compartmentalize it away.  For lots of changes you 
only have to consider the pure stuff which is easier to think about (no 
worries about state, no worries about the right order of doing things, 
program in a declarative fashion).  The downside is you have to put all the 
side-effect stuff in a corner and box it off.  This can be a little odd 
because it may make you organize your code in a counterintuitive way.  Also 
it makes side-effect creep very obvious (when you realize "oops, that needs 
to be in a monad too... and that... and that ... crap").  You really have to 
sit down and think about the design before you do anything.  Haskell is 
definitely a first-on-paper, then-in-code type of language.  This can be good 
because for complex stuff you probably want to think about the design ahead 
of time anyways.  Haskell forces this discpline on you.  On the other hand, 
if you like to do rapid prototyping type of approach and live on the edge a 
bit, it can be a bummer.

A similar argument follows for lazy (non-strict) evaluation as well.  Allows 
some really cool stuff (eg. infinite lists) and optimizations (eg. 
deforestation).  But has significant overhead (eg. you have to make a thunk 
for everything, if you're going to evaluate it anyways, all that work to make 
the thunk is wasted) and it's hard to reason about speed and memory 
performance (eg. it looks like a tail recursive function that uses constant 
stack space but because the accumulator is thunked, you end up creating O(N) 
thunks).

Anyways, I think Haskell has some really cool ideas and I like it.  It 
definitely expands the mind.  But OCaml is my go-to-swiss-army-knife of 
languages.  It used to be C but that was too low level for me and library 
support was crap (this was before Boost).  Then it was Java but it was waay 
to verbose and you couldn't even return a tuple without creating a class for 
it first.  Then it was Lisp, but it's dynamically typed and I got tired of 
finding bugs from 3 years ago.  Now days it's OCaml.  Maybe one day it'll be 
something else, but in the mean time, I'm enjoying it.

Peng
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Re: [Caml-list] Haskell vs OCaml

[Peng Zang]

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On Thursday 14 August 2008 09:57:47 am Jon Harrop wrote:
> Monads and zippers?

They can be useful for the same reasons they are in Haskell.  You can always 
write OCaml code like Haskell code, it's just not always easiest to do it 
that way.

> Even if Haskell's performance is improved it will remain unpredictable and,
> consequently, it will continue to be impossible to optimize non-trivial
> Haskell programs.

That's true, but I think Haskell's point of view is to stop that completely.  
They want to remove optimization of code and put it into the hands of the 
compiler.  The ideal is to say to the programmer: "don't worry about 
performance and optimization, just write correct code.  The compiler will 
figure out the rest".  Clearly we're not at that point, and perhaps that 
ideal is a long ways to become true if possible at all.  But you gotta give 
them props for the idea.  It would be nice to only care about correctness and 
not performance.

Peng
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Re: [Caml-list] Haskell vs OCaml

[Vincent Hanquez]

On Thu, Aug 14, 2008 at 02:57:47PM +0100, Jon Harrop wrote:
> > and Haskell is faster than most (scripting) languages used these days
> > anyway). 
> 
> Despite being written in Python, Mercurial is orders of magnitude faster than 
> Darcs.

(wow, very funny)

by the same stupid thinking process:

Despite being written in C, CVS is orders of magnitude slower than
mercurial. obviously now, python is faster than C.

-- 
Vincent

Re: [Caml-list] Haskell vs OCaml

[Jon Harrop]

On Thursday 14 August 2008 15:21:40 you wrote:
> On Thu, Aug 14, 2008 at 02:57:47PM +0100, Jon Harrop wrote:
> > > and Haskell is faster than most (scripting) languages used these days
> > > anyway).
> >
> > Despite being written in Python, Mercurial is orders of magnitude faster
> > than Darcs.
>
> (wow, very funny)
>
> by the same stupid thinking process:
>
> Despite being written in C, CVS is orders of magnitude slower than
> mercurial.

Is that based upon any measurements?

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/products/?e

Re: [Caml-list] Haskell vs OCaml

[Erik de Castro Lopo]

Jon Harrop wrote:

> 184,574: FFTW (14,298 lines of OCaml)

For FFTW, Ocaml is used the generate C code. Nothing that the final
user of libfftw links to is written in Ocaml. I don't think this one
really counts.

> Some of the Haskell projects (e.g. pugs and srcinst) have even *decreased* 
> in popularity over the past 7 months. Indeed, Darcs was only being used to a 
> significant extent by the Haskell community and the GHC developers are now 
> giving up on it themselves citing awful performance as one of the main 
> reasons:
> 
>   http://hackage.haskell.org/trac/ghc/wiki/DarcsEvaluation

Darcs with its theory of patches is also far more experimental and is pushing
back the boundaries of how people who write revision control software think
about the field.

Erik
-- 
-----------------------------------------------------------------
Erik de Castro Lopo
-----------------------------------------------------------------
"Incompetence, like misery, seeks company." -- Erik Naggum

Re: [Caml-list] Haskell vs OCaml

[Nicolas Pouillard]

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Excerpts from Jon Harrop's message of Thu Aug 14 15:57:47 +0200 2008:
> On Thursday 14 August 2008 12:50:43 blue storm wrote:
...
> > and Haskell is faster than most (scripting) languages used these days
> > anyway). 
> 
> Despite being written in Python, Mercurial is orders of magnitude faster than 
> Darcs.

The difference of performances between Darcs and Mercurial is 99% due
differences in algorithms not in the implementation language. So this
comparison does not make sense!

-- 
Nicolas Pouillard aka Ertai

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Re: [Caml-list] Haskell vs OCaml

[Jon Harrop]

On Thursday 14 August 2008 21:57:59 you wrote:
> Excerpts from Jon Harrop's message of Thu Aug 14 15:57:47 +0200 2008:
> > On Thursday 14 August 2008 12:50:43 blue storm wrote:
> > > and Haskell is faster than most (scripting) languages used these days
> > > anyway).
> >
> > Despite being written in Python, Mercurial is orders of magnitude faster
> > than Darcs.
>
> The difference of performances between Darcs and Mercurial is 99% due
> differences in algorithms not in the implementation language. So this
> comparison does not make sense!

Only if the choice of algorithm was independent of the language, which is 
rarely the case.

For example, Fortran programmers use arrays when they are unsuitable and their 
programs can be slower than scripting languages as a consequence. That is 
Fortran's fault.

Does the Darcs implementation overuse singly linked lists because they are 
more accessible? Are the reported stack overflows indicative of this? I don't 
know but I certainly wouldn't rule it out as a possibility.

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/products/?e

Re: [Caml-list] Haskell vs OCaml

[Nicolas Pouillard]

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Excerpts from Jon Harrop's message of Thu Aug 14 23:16:26 +0200 2008:
> On Thursday 14 August 2008 21:57:59 you wrote:
> > Excerpts from Jon Harrop's message of Thu Aug 14 15:57:47 +0200 2008:
> > > On Thursday 14 August 2008 12:50:43 blue storm wrote:
> > > > and Haskell is faster than most (scripting) languages used these days
> > > > anyway).
> > >
> > > Despite being written in Python, Mercurial is orders of magnitude faster
> > > than Darcs.
> >
> > The difference of performances between Darcs and Mercurial is 99% due
> > differences in algorithms not in the implementation language. So this
> > comparison does not make sense!
> 
> Only if the choice of algorithm was independent of the language, which is 
> rarely the case.
> 
> For example, Fortran programmers use arrays when they are unsuitable and their 
> programs can be slower than scripting languages as a consequence. That is 
> Fortran's fault.
> 
> Does the Darcs implementation overuse singly linked lists because they are 
> more accessible? Are the reported stack overflows indicative of this? I don't 
> know but I certainly wouldn't rule it out as a possibility.

I'm talking about the informal algorithms, their independent of that kind of
things...

-- 
Nicolas Pouillard aka Ertai

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Re: [Caml-list] Haskell vs OCaml

[Jon Harrop]

On Thursday 14 August 2008 22:50:19 you wrote:
> I'm talking about the informal algorithms, their independent of that kind
> of things...

Yes, that may well be true. I think we would need in-depth knowledge of Darcs 
to be able to distinguish between the two.

Do any OCaml projects use Darcs, BTW?

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/products/?e

Re: [Caml-list] Haskell vs OCaml

[Stéphane Glondu]

Jon Harrop wrote:
> Do any OCaml projects use Darcs, BTW?

Ocsigen¹ does.

¹ http://ocsigen.org/

-- 
Stéphane Glondu

Re: [Caml-list] Haskell vs OCaml

[blue storm]

> One is that Haskell forces your program into two parts.  Parts that contain
> side-effects (in monads) and the part that is pure.

You can actually do quite a bit more, using different monads to
compartementalize different aspects of your code. You will, by the
way, have noticed that Haskellers tend to put everything in the IO
monad (when a separate monad would make more sense) because mixing
monads is difficult.

> This is great because
> the compiler can now do some optimizations not available when you don't know
> if your code is pure.

I suppose you could get the same benefits with a "purity inference"
compiler pass, the same way haskell compilers a "strictness
inference".

> it makes side-effect creep very obvious (when you realize "oops, that needs
> to be in a monad too... and that... and that ... crap").

unsafePerformIO to the rescue !

I generally agree with the interest of pure programming in some part
of the language. It is, however, not all as rosy as you say (i've seen
people argue that the "side-effect creep" related to monads cause
composability problems) because they are hard issue (monads mixing for
example) wich have not been quite resolved yet. Haskell is interesting
because of that experimental taste, but i totally agree it "sometimes
gets in your way".

> A similar argument follows for lazy (non-strict) evaluation as well.  Allows
> some really cool stuff (eg. infinite lists) and optimizations (eg.
> deforestation).

Explicit lazy evaluation (as in OCaml) can give you the same cool
stuff, with a saner standard (strict evaluation) and, in my opinion,
increased comprehensibility (by explicitely highlighting the part that
rely on lazy evaluation). Both library and syntaxic support of lazy
values in OCaml could be better that they are now, but they is work
going on (we even have *several* lazy lists librairies these day).


> That's true, but I think Haskell's point of view is to stop that completely.
> They want to remove optimization of code and put it into the hands of the
> compiler.  The ideal is to say to the programmer: "don't worry about
> performance and optimization, just write correct code.  The compiler will
> figure out the rest".

I strongly disagree on that point. You just can't rely on anything
that optimizes "as much as possible" when you don't know precisely
what it does. The idea to "not worry about performance" is, in my
opinion, wrong because you'll always have specific cases wich are not
correctly optimized (see for example the posts on the performance of
high-level automatic differentiation stuff that went on the Haskell
planet a month ago or so). The usual programmer should not need to
know about subtle and implementation-specific stuff (whereas the
requirement of understanding tail-recursion is commonly accepted among
OCaml programmers), but trying to optimize every naive code into
something efficient is a dangerous dream.

Re: [Caml-list] Haskell vs OCaml

[Luca Saiu]

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Jon Harrop wrote:
> On Thursday 14 August 2008 22:50:19 you wrote:
>> I'm talking about the informal algorithms, their independent of that kind
>> of things...
> 
> Yes, that may well be true. I think we would need in-depth knowledge of Darcs 
> to be able to distinguish between the two.
> 
> Do any OCaml projects use Darcs, BTW?

We use Darcs as the VCS for Marionnet. See http://darcs.marionnet.org .

Darcs 2 has yet to give us any headache; the "exponential merge" corner
cases of version 1 are apparently gone, and now it's quite a pleasure to
use.

- --
Luca Saiu
http://www-lipn.univ-paris13.fr/~saiu
GNU epsilon: http://www.gnu.org/software/epsilon
Marionnet:   http://www.marionnet.org
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Re: [Caml-list] Haskell vs OCaml

[Paul Snively]

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FWIW, I still use darcs (darcs 2) exclusively. So far, no other  
version control system has gotten the relationships among  
repositories, branching, and merging quite right, although I'm keeping  
a keen eye on Mercurial's forthcoming "rebase" extension.

On Aug 14, 2008, at 5:15 PM, Jon Harrop wrote:

> On Thursday 14 August 2008 22:50:19 you wrote:
>> I'm talking about the informal algorithms, their independent of  
>> that kind
>> of things...
>
> Yes, that may well be true. I think we would need in-depth knowledge  
> of Darcs
> to be able to distinguish between the two.
>
> Do any OCaml projects use Darcs, BTW?
>
> -- 
> Dr Jon D Harrop, Flying Frog Consultancy Ltd.
> http://www.ffconsultancy.com/products/?e
>
> _______________________________________________
> Caml-list mailing list. Subscription management:
> http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list
> Archives: http://caml.inria.fr
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs

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Re: [Caml-list] Haskell vs OCaml

[Dr. Thomas Fischbacher]

circ ular wrote:

> What are the advantages/disadvantages when comparing OCaml to Haskell?

What are the advantages/disadvantages when comparing a fork to a spoon?

-- 
best regards,
Thomas Fischbacher
t.fischbacher@soton.ac.uk

Re: [Caml-list] Haskell vs OCaml

[DooMeeR]

> What are the advantages/disadvantages when comparing a fork to a spoon?

 From Church's thesis, one can easily answer this question: they are 
equivalent.

The reduction is quite easy. A fork can be reduced to a spoon using a 
fire, an anvil and a hammer, and a spoon can be reduced to a fork using 
a saw.

Hope this helps.

-- 
Romain Bardou

Re: [Caml-list] Haskell vs OCaml

[David Teller]

I'm not sure there's confluence if you factor in the resources required
for such reduction, though.

On Thu, 2008-08-21 at 10:47 +0200, DooMeeR wrote:
> > What are the advantages/disadvantages when comparing a fork to a spoon?
> 
>  From Church's thesis, one can easily answer this question: they are 
> equivalent.
> 
> The reduction is quite easy. A fork can be reduced to a spoon using a 
> fire, an anvil and a hammer, and a spoon can be reduced to a fork using 
> a saw.
> 
> Hope this helps.
> 
-- 
David Teller-Rajchenbach
 Security of Distributed Systems
  http://www.univ-orleans.fr/lifo/Members/David.Teller
 Angry researcher: French Universities need reforms, but the LRU act brings liquidations. 

Re: [Caml-list] Haskell vs OCaml

[Dr. Thomas Fischbacher]

DooMeeR wrote:

>>What are the advantages/disadvantages when comparing a fork to a spoon?
> 
>  From Church's thesis, one can easily answer this question: they are
> equivalent.
> 
> The reduction is quite easy. A fork can be reduced to a spoon using a
> fire, an anvil and a hammer, and a spoon can be reduced to a fork using
> a saw.

So, why at all bother with OCaml if it's equivalent to Basic anyway, or
machine language, for that matter?

Church's Thesis is often cited for precisely this purpose of cutting off
discussions related to differing aspects of programming languages --
sometimes this may even seem a Pawlowian reflex reaction. However,
I think Church is a red herring here, as the important aspects of
programming languages are not at the language:machine interface, but
at the human:language interface. The design of a milk carton certainly
does not matter a lot for how well it manages to store milk -- pretty
much all of them do that quite well. But it certainly does matter for
the question whether I'll spill milk all over the table when I try to
put some into my tea (as I did this morning).

-- 
best regards,
Thomas Fischbacher
t.fischbacher@soton.ac.uk

Re: [Caml-list] Haskell vs OCaml

[Nicolas Braud-Santoni]

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On 19/03/2013 02:23, Francois Berenger wrote:
> On 03/18/2013 08:26 PM, Kakadu wrote:
>> Please, don't feed the troll
>>
>> On Mon, Mar 18, 2013 at 1:48 PM, Malcolm Matalka <mmatalka@gmail.com>
>> wrote:
>>> The biggest advantage for me is Ocaml is simpler than Haskell IMO.
>>>
>>> adrian.alexander.may@gmail.com writes:
>>>
>>>> On Wednesday, 13 August 2008 20:49:17 UTC+8, circ ular  wrote:
>>>>> What are the advantages/disadvantages when comparing OCaml to
>>>>> Haskell?
>>>>
>>>> case you of
>>>>    man   -> haskell
>>>>    mouse -> ocaml
>
> Last time I used it, the Haskell "ecosystem" around the language
> (tools and libraries) was quite advanced (they had an OPAM-like
> long time ago for example).

As a Haskell programmer, I can tell you that Cabal (Haskell's OPAM-like)
is somewhat quirky, and can become very painful to work around when
hitting some corner-cases.

For now, I have had no such experience with OPAM ;)


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Re: [Caml-list] Haskell vs OCaml

[Kristopher Micinski]

I agree, but I've found templates in TH to be a bit sticky since they
lack a lot of semantic support.  Maybe it's just an aversion to
quasiquoters from examples I've seen.  Although I do understand that
within Yesod TH does have quite a bit of success.  I guess my only
real point was extrapolating from examples of people I know that use
camlp4 for language extensions (within a research context) and not TH.
I haven't ruminated as to whether TH would suffice for individual
instances (probably so, and the people I know simply prefer OCaml..).

In any case the newer versions of OCaml actually export the compiler,
which makes some other language analysis-y things slightly easier from
an API standpoint.

Kris

On Mon, Mar 25, 2013 at 10:37 PM, Erik de Castro Lopo
<mle+ocaml@mega-nerd.com> wrote:
> Kristopher Micinski wrote:
>
>> Although I haven't personally used it, Camlp4 is nice (and used by
>> research) for implementing language extensions.  I'm not sure that GHC
>> is quite as hackable / extensible, but maybe that's just because I'm
>> uninformed about Haskell :-)..
>
> I suspect that Template Haskell is probably very near to Camlp4 in
> terms of capabilities. Its also relatively widely used, for instance
> in the Yesod web framework.
>
> Erik
> --
> ----------------------------------------------------------------------
> Erik de Castro Lopo
> http://www.mega-nerd.com/
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs

Re: [Caml-list] Haskell vs OCaml

[Erik de Castro Lopo]

Kristopher Micinski wrote:

> Although I haven't personally used it, Camlp4 is nice (and used by
> research) for implementing language extensions.  I'm not sure that GHC
> is quite as hackable / extensible, but maybe that's just because I'm
> uninformed about Haskell :-)..

I suspect that Template Haskell is probably very near to Camlp4 in
terms of capabilities. Its also relatively widely used, for instance
in the Yesod web framework.

Erik
-- 
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/

Re: [Caml-list] Haskell vs OCaml

[Kristopher Micinski]

One other potentially unmentioned point is basically that Haskell is
call by need and OCaml is call by value.  This causes a bit of a
headache sometimes (lazy io, etc, etc...), but birthed some cool
constructs (such as iteratees).

I personally find Haskell *harder* to understand because of all the
hoops you have to jump through to be purely functional (but maybe
that's just me).

Although I haven't personally used it, Camlp4 is nice (and used by
research) for implementing language extensions.  I'm not sure that GHC
is quite as hackable / extensible, but maybe that's just because I'm
uninformed about Haskell :-)..

Kris

On Mon, Mar 18, 2013 at 5:08 AM,  <adrian.alexander.may@gmail.com> wrote:
> On Wednesday, 13 August 2008 20:49:17 UTC+8, circ ular  wrote:
>> What are the advantages/disadvantages when comparing OCaml to Haskell?
>
> case you of
>   man   -> haskell
>   mouse -> ocaml
>
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs

Re: [Caml-list] Haskell vs OCaml

[Francois Berenger]

On 03/18/2013 08:26 PM, Kakadu wrote:
> Please, don't feed the troll
>
> On Mon, Mar 18, 2013 at 1:48 PM, Malcolm Matalka <mmatalka@gmail.com> wrote:
>> The biggest advantage for me is Ocaml is simpler than Haskell IMO.
>>
>> adrian.alexander.may@gmail.com writes:
>>
>>> On Wednesday, 13 August 2008 20:49:17 UTC+8, circ ular  wrote:
>>>> What are the advantages/disadvantages when comparing OCaml to Haskell?
>>>
>>> case you of
>>>    man   -> haskell
>>>    mouse -> ocaml

Last time I used it, the Haskell "ecosystem" around the language
(tools and libraries) was quite advanced (they had an OPAM-like
long time ago for example).

Also, the population of Haskell programmers might be bigger
(bigger open-source community, easier to find programmers to hire).

F.

Re: [Caml-list] Haskell vs OCaml

[Kakadu]

Please, don't feed the troll

On Mon, Mar 18, 2013 at 1:48 PM, Malcolm Matalka <mmatalka@gmail.com> wrote:
> The biggest advantage for me is Ocaml is simpler than Haskell IMO.
>
> adrian.alexander.may@gmail.com writes:
>
>> On Wednesday, 13 August 2008 20:49:17 UTC+8, circ ular  wrote:
>>> What are the advantages/disadvantages when comparing OCaml to Haskell?
>>
>> case you of
>>   man   -> haskell
>>   mouse -> ocaml
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs

Re: [Caml-list] Haskell vs OCaml

[Adrian May]

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Actually I was making a serious point, namely, that Haskell forces you to
learn the whole FP deal even to write Hello World, whereas Ocaml lets you
chicken out into imperative programming at the first hurdle. Which is
better? Well I'd say the former because the latter risks building up a code
base that doesn't rhyme with itself and a population of programmers who
react to one half or the other of the code with either derision or
confusion.



On 18 March 2013 17:59, Gabriel Scherer <gabriel.scherer@gmail.com> wrote:

> I see no point in keeping this thread going on, given the mediocre way
> it started.
>
> The original question was about feedback on OCaml being used to teach
> programming, and I think it is good that is answered in detail if it
> can help in making informed curriculum decisions. Don't hesitate to
> keep providing data if you think it helps.
>
> On the other side, there is no "competition" going on here -- and it's
> indeed an excellent thing that Haskell, being a beautiful language, is
> also taught at university (same for SML)! If only there were less Java
> courses...
>
> I'm sure there are interesting things to be said about "Haskell and
> OCaml" (rather than "vs."), but this is not the way to start it.
>
> "Keep Caml and Curry On"!
>
> On Mon, Mar 18, 2013 at 10:48 AM, Malcolm Matalka <mmatalka@gmail.com>
> wrote:
> > The biggest advantage for me is Ocaml is simpler than Haskell IMO.
> >
> > adrian.alexander.may@gmail.com writes:
> >
> >> On Wednesday, 13 August 2008 20:49:17 UTC+8, circ ular  wrote:
> >>> What are the advantages/disadvantages when comparing OCaml to Haskell?
> >>
> >> case you of
> >>   man   -> haskell
> >>   mouse -> ocaml
> >
> > --
> > Caml-list mailing list.  Subscription management and archives:
> > https://sympa.inria.fr/sympa/arc/caml-list
> > Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> > Bug reports: http://caml.inria.fr/bin/caml-bugs
>

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Re: [Caml-list] Haskell vs OCaml

[Gabriel Scherer]

I see no point in keeping this thread going on, given the mediocre way
it started.

The original question was about feedback on OCaml being used to teach
programming, and I think it is good that is answered in detail if it
can help in making informed curriculum decisions. Don't hesitate to
keep providing data if you think it helps.

On the other side, there is no "competition" going on here -- and it's
indeed an excellent thing that Haskell, being a beautiful language, is
also taught at university (same for SML)! If only there were less Java
courses...

I'm sure there are interesting things to be said about "Haskell and
OCaml" (rather than "vs."), but this is not the way to start it.

"Keep Caml and Curry On"!

On Mon, Mar 18, 2013 at 10:48 AM, Malcolm Matalka <mmatalka@gmail.com> wrote:
> The biggest advantage for me is Ocaml is simpler than Haskell IMO.
>
> adrian.alexander.may@gmail.com writes:
>
>> On Wednesday, 13 August 2008 20:49:17 UTC+8, circ ular  wrote:
>>> What are the advantages/disadvantages when comparing OCaml to Haskell?
>>
>> case you of
>>   man   -> haskell
>>   mouse -> ocaml
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs

Re: [Caml-list] Haskell vs OCaml

[Malcolm Matalka]

The biggest advantage for me is Ocaml is simpler than Haskell IMO.

adrian.alexander.may@gmail.com writes:

> On Wednesday, 13 August 2008 20:49:17 UTC+8, circ ular  wrote:
>> What are the advantages/disadvantages when comparing OCaml to Haskell?
>
> case you of
>   man   -> haskell
>   mouse -> ocaml

Re: [Caml-list] Haskell vs OCaml

[adrian.alexander.may]

On Wednesday, 13 August 2008 20:49:17 UTC+8, circ ular  wrote:
> What are the advantages/disadvantages when comparing OCaml to Haskell?

case you of
  man   -> haskell
  mouse -> ocaml

Re: [Caml-list] Haskell vs OCaml

[Damien Guichard]

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Well said Brian.

Any tutorial is good enough at underlining respective language features.
Haskell has lazy evaluation, Caml has strict evaluation, don't pretend it's a secret and don't ask whether good or bad. 
Be responsible, try it yourself if needed, then choose yourself.

- damien






> circ ular wrote:
>
> > What are the advantages/disadvantages when comparing OCaml to Haskell?
> 
>
> The biggest disadvantage of comparing Ocaml to Haskell would have to be 
> causing a long, pointless flamewar. Offhand, I can't think of an upside.
>
> Brian

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