Not exactly: The aim is not to know which path must the water take to the
least time.
The fact is, the water can only take one path, due to the circuit
configuration, from the source to the exit, so there is no choice for the
water.
It's not a graph with multiple paths, it's a tree with leafs as
Hello,
I had for long thought that data and newtype were equivalent, but then I
spotted some differences when it comes to strictness.
Those can be summed up as:
data Test = Test Int
newtype TestN = TestN Int
pm (Test _) = 12 -- Strict (pm undefined = undefined)
pm2 t = t `seq` 12 -- Strict
* Yves Parès yves.pa...@gmail.com [2012-01-22 11:32:30+0100]
These make me think that pattern matching against a newtype is always lazy
(irrefutable). Am I right?
Yes.
Is there some litterature expliciting in a less empiric way than I did the
differences like this between data and newtype?
I don't know so much about ghc-7.4, but if loading dph codes in ghci
is the main matter here, below might help:
http://warmfuzzything.posterous.com/loading-dph-codes-in-ghci
Best,
--
Atsuro Hoshino
On Sun, Jan 22, 2012 at 2:58 AM, Brandon Allbery allber...@gmail.com wrote:
On Sat, Jan 21,
Yves Parès wrote:
Is there some litterature expliciting in a less empiric way than I did the
differences like this between data and newtype? I've never come against
such documentation through all my learning of Haskell, yet I think it's an
important point.
Roman Cheplyaka wrote:
See the
Thanks, that's clearer to me now.
It confirmed my thoughts:
Matching the pattern con pat against a value, where con is a constructor
defined by newtype, depends on the value:
- If the value is of the form con v, then pat is matched against v.
- If the value is ⊥, then pat is matched against ⊥.
Big sum up of everything:
If TestN is a newtype constructor, then
'TestN undefined' and 'undefined' are exactly the same thing.
2012/1/22 Yitzchak Gale g...@sefer.org
Yves Parès wrote:
Is there some litterature expliciting in a less empiric way than I did
the
differences like this
* Yves Parès yves.pa...@gmail.com [2012-01-22 15:23:51+0100]
Big sum up of everything:
If TestN is a newtype constructor, then
'TestN undefined' and 'undefined' are exactly the same thing.
To be precise, the former is a type-restricted version of the latter.
--
Roman I. Cheplyaka ::
On Sat, Jan 21, 2012 at 8:09 PM, David Barbour dmbarb...@gmail.com wrote:
In any case, I think the monad identity concept messed up. The property:
return x = f = f x
Logically only has meaning when `=` applies to values in the domain.
`undefined` is not a value in the domain.
We can
observably different from `undefined`
If we understand `undefined` as meaning a computation that never ends, then
you cannot ever observe whether one `undefined` is or is not equivalent to
another. In strict languages, this is especially obvious.
In any case, I don't accept a concept of
Отправлено с iPad
22.01.2012, в 20:25, David Barbour dmbarb...@gmail.com написал(а):
Attempting to shoehorn `undefined` into your reasoning about domain algebras
and models and monads is simply a mistake.
No. Using the complete semantics — which includes bottoms aka undefined — is a
2012/1/22 MigMit miguelim...@yandex.ru
Отправлено с iPad
22.01.2012, в 20:25, David Barbour dmbarb...@gmail.com написал(а):
Attempting to shoehorn `undefined` into your reasoning about domain
algebras and models and monads is simply a mistake.
No. Using the complete semantics — which
I try to create a workflow for this sort of thing. I create a package
with a name like set-extra, with one module Data.Set.Extra and an
alternative Data.Set module that exports both the old Data.Set and the
symbols in Data.Set.Extra. Then I email the maintainers of the
Containers package with a
Replies are inline. Thanks for the quick and thoughtful response!
On Sat, Jan 21, 2012 at 8:56 AM, Michael Snoyman mich...@snoyman.comwrote:
Hi Myles,
These sound like two solid features, and I'd be happy to merge in code to
support it. Some comments below.
On Sat, Jan 21, 2012 at 8:38 AM,
Thank you. It helped me lot.
Regards
Mukesh Tiwari
On Sun, Jan 22, 2012 at 7:14 PM, Atsuro Hoshino hoshinoats...@gmail.comwrote:
I don't know so much about ghc-7.4, but if loading dph codes in ghci
is the main matter here, below might help:
What is natural Haskell representation of such enum?
enum TypeMask
{
UNIT,
GAMEOBJECT,
CREATURE_OR_GAMEOBJECT = UNIT | GAMEOBJECT
};
More sophisticated question is: and what data structures must be used when
converting this naturally one to Haskell?
// 1-byte flaged enum
enum TypeMask
Performing bit-mask operations is possible via the Data.Bits operations (on
elements of type Word8 or Word16, etc.). But I must say, it doesn't seem
very `natural` in Haskell, nor even in other languages. It crosses lines,
binding abstraction to representation in order to improve efficiency.
The
Данило Глинський wrote:
What is natural Haskell representation of such enum?
enum TypeMask
{
UNIT,
GAMEOBJECT,
CREATURE_OR_GAMEOBJECT = UNIT | GAMEOBJECT
};
data ObjectType = Unit | GameObject
creatureOrGameObject :: ObjectType - Bool
creatureOrGameObject Unit = True
I may be curious to see how you intend to use such enum...
It is very C-wise, I'm not sure it will be very handy, but I need some
context.
2012/1/22 Данило Глинський abcz2.upr...@gmail.com
What is natural Haskell representation of such enum?
enum TypeMask
{
UNIT,
GAMEOBJECT,
On 21/01/2012, at 22:47 , mukesh tiwari wrote:
Hello all
I have installed ghc-7.4.0.20111219 and this announcement says that The
release candidate accidentally includes the random, primitive, vector and dph
libraries. The final release will not include them. I tried to compile a
On 21/01/2012 5:45 AM, Ryan Ingram wrote:
Has anyone played with Idris (http://idris-lang.org/) at all? It looks
interesting, and I'd love to play with it, but unfortunately I only have
windows machines up and running at the moment and the documentation seems
to imply it only builds on unixy
On Sun, Jan 22, 2012 at 11:07 PM, Myles C. Maxfield
myles.maxfi...@gmail.com wrote:
Replies are inline. Thanks for the quick and thoughtful response!
On Sat, Jan 21, 2012 at 8:56 AM, Michael Snoyman mich...@snoyman.com
wrote:
Hi Myles,
These sound like two solid features, and I'd be happy
1. Oops - I overlooked the fact that the redirectCount attribute of a
Request is exported (it isn't listed on the
documentationhttp://hackage.haskell.org/packages/archive/http-conduit/1.2.0/doc/html/Network-HTTP-Conduit.html
probably
because the constructor itself isn't exported. This seems like a
On Mon, Jan 23, 2012 at 8:31 AM, Myles C. Maxfield
myles.maxfi...@gmail.com wrote:
1. Oops - I overlooked the fact that the redirectCount attribute of a
Request is exported (it isn't listed on the documentation probably because
the constructor itself isn't exported. This seems like a flaw in
Just make sure Cookie handling can be disabled completely.
Aristid
Am 23.01.2012 07:44 schrieb Michael Snoyman mich...@snoyman.com:
On Mon, Jan 23, 2012 at 8:31 AM, Myles C. Maxfield
myles.maxfi...@gmail.com wrote:
1. Oops - I overlooked the fact that the redirectCount attribute of a
Hi all,
I'm trying to cabal install hspec and I get the following:
Resolving dependencies...
/tmp/hspec-0.9.04062/hspec-0.9.0/Setup.lhs:2:10:
Could not find module `System'
It is a member of the hidden package `haskell98-2.0.0.0'.
Use -v to see a list of the
Alright, that sounds good to me. I'll get started on it (the IORef idea).
Thanks for the insight!
--Myles
On Sun, Jan 22, 2012 at 10:42 PM, Michael Snoyman mich...@snoyman.comwrote:
On Mon, Jan 23, 2012 at 8:31 AM, Myles C. Maxfield
myles.maxfi...@gmail.com wrote:
1. Oops - I overlooked the
The only times cookies would be used would be:
1. If you explicitly use it.
2. If you have redirects turned on, and a page that redirects you also
sets a cookie.
I would think that we would want (2) to be on regardless of user
setting, do you disagree?
Michael
On Mon, Jan 23, 2012 at 8:46 AM,
I'm a little confused as to what you mean by 'cookie handling'. Do you mean
cookies being set inside redirects for future requests inside the same
redirect chain, or users being able to supply cookies to the first HTTP
request and pull them out of the last HTTP response?
Clearly, making the
Indeed, I disagree on 2. Sometimes there is an API and cookies are just not
part of it (and redirects are).
Aristid
Am 23.01.2012 08:16 schrieb Michael Snoyman mich...@snoyman.com:
The only times cookies would be used would be:
1. If you explicitly use it.
2. If you have redirects turned on,
That's a violation of the spec. Having a server set a cookie and then
not really mean it or something along those lines would be invalid.
And having a server not set a cookie at all means having this feature
would be irrelevant.
On Mon, Jan 23, 2012 at 9:42 AM, Aristid Breitkreuz
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