On Thu, Jun 02, 2005 at 05:03:26PM -0400, S. Alexander Jacobson wrote:
> Any reason the libaries don't define:
>
> class HasNull a where null::a->Bool
> class HasEmpty a where empty::a
>
> I find that I sometimes switch between using lists, sets, or tables as
> my collection type and the for
Any reason the libaries don't define:
class HasNull a where null::a->Bool
class HasEmpty a where empty::a
I find that I sometimes switch between using lists, sets, or tables as
my collection type and the forced import qualifification for generic
collection operations seems annoying.
-Ale
Christian Maeder wrote:
Mario Blazevic wrote:
mapFilter :: (a -> Maybe b) -> Map k a -> Map k b
mapFilter f = map Maybe.fromJust . filter Maybe.isJust . map f
How about using Map.foldWithKey (and adding "Ord k =>" to the type
signature)?
mapFilter f = Map.foldWithKey ( \ k -> maybe
Mario Blazevic wrote:
> mapFilter :: (a -> Maybe b) -> Map k a -> Map k b
> mapFilter f = map Maybe.fromJust . filter Maybe.isJust . map f
How about using Map.foldWithKey (and adding "Ord k =>" to the type
signature)?
mapFilter f = Map.foldWithKey ( \ k -> maybe id (Map.insert k) . f)
Map
This being the topic, I'll list the issues I ran into with the new
Data.Map library:
1. The function Map.union is left-biased whereas the old
FiniteMap.unionFM was right-biased. The change seems rather arbitrary.
There are also other changes of this kind, the following two notable
among them:
Serge D. Mechveliani wrote:
> As Jens Fisseler notes, I have made a confusion about
>
> Set.elems, Set.toList, Set.setToList.
There is even Set.toAscList (although one may argue that should be
Set.toDistinctAscList)
I think the right choice is Set.toList (replacing setToList)
Is Set.elems just
The ghc-6.4 documentation says about Data.Map
"
insert :: Ord k => k -> a -> Map k a -> Map k a
O(log n). Insert a new key and value in the map.
"
If this is to replace old addToFM, then it is better to remove the
word "new".
Right?
-
Serge Mechveliani
[EMAIL PROTECTED]
___
Hello Simon,
Thursday, June 02, 2005, 12:26:48 PM, you wrote:
SM> You mean allowing
SM> import M hiding (x)
SM> even if x is not exported by M? Or making it a warning?
yes. i think that warning will be enough - it will compile silently
with new library versions and give warning, but still c
As Jens Fisseler notes, I have made a confusion about
Set.elems, Set.toList, Set.setToList.
Docs on setToList occurs all right (`Obsolete' item).
And for some reason, Data.Set.html shows the pair
> > "
> > elems :: Set a -> [a]
> > O(n). The elements of a set.
> >
> > toList :: Set a
> I meant the description in the ghc-6.4 documentation.
> Data.Set.html says
> "
> elems :: Set a -> [a]
> O(n). The elements of a set.
>
> setToList :: Set a -> [a]
> O(n). Convert the set to a list elements.
> "
> What is the difference?
> If they are really equivalent, then, it is nat
Thanks to people for the explanations.
To my question
>> 1. elems :: Set a -> [a]
>> setToList :: Set a -> [a]
>>
>> These two look like synonyms, but have different comments.
>> Am I missing something?
Jens Fisseler <[EMAIL PROTECTED]>
writes on 2 Jun 2005
> Both functions compu
The definition of the Set datatype being
data Set a= Tip
| Bin {-# UNPACK #-} !Size a !(Set a) !(Set a)
type Size = Int
It seems your're out of luck when it comes to very large sets.
Also, since the structure is strict, it makes little sense to support
4-million-element
On 01 June 2005 07:24, Bulat Ziganshin wrote:
> Hello Fergus,
>
> Tuesday, May 31, 2005, 10:24:41 PM, you wrote:
>
>>> import Data.Set hiding (map)
>>> import qualified Data.Set as Set
>>>
>>> will do fine.
>
>> That code only compiles with ghc 6.4, and won't compile with ghc 6.2:
>> you'll ge
On 01 June 2005 13:54, Jens Fisseler wrote:
> I'm currently trying to optimize some code, in particular trying to
> make some functions as strict as possible. To do this, I quite often
> look for strictness annotations either in the interface files or the
> the simplifier output. Doing this, somet
On 02 June 2005 08:22, Krasimir Angelov wrote:
> I just tried to update and build my CVS tree, but the compilation
> failed for base package. In the 'make boot' the .depend file is
> created but it contains only the C part. The compiler is invoked as
> normal and there isn't any error. The compila
On Thu, Jun 02, 2005 at 09:23:43AM +0100, Simon Marlow wrote:
> On 01 June 2005 12:51, Serge D. Mechveliani wrote:
>
> > The problem was that I could not find these .gz archives by
> > following the www references. I wonder what I was missing.
> > Now, as I read your letter, I go to .../docs/l
On 01 June 2005 12:51, Serge D. Mechveliani wrote:
> The problem was that I could not find these .gz archives by
> following the www references. I wonder what I was missing.
> Now, as I read your letter, I go to .../docs/latest/ and observe
> them.
The printable documentation is linked fro
> 1. elems :: Set a -> [a]
> setToList :: Set a -> [a]
>
> These two look like synonyms, but have different comments.
> Am I missing something?
Both functions compute the same list, and IMHO the comments state the
same.
> 2. size :: Set a -> Int-- O(1) ...
>
> And for large
6. My module applies Data.Set.null (s :: Set a),
and null (xs :: [a]).
Why ghc reports of the clash with GHC.List.null ?
Is GHC.List same as old List library module?
Should I write
import GHC.List (genericLength, null)
instead of import Li
Hello, Guys
I just tried to update and build my CVS tree, but the compilation
failed for base package. In the 'make boot' the .depend file is
created but it contains only the C part. The compiler is invoked as
normal and there isn't any error. The compilation is failing latter
when it tries to bui
Dear GHC team,
I am looking into the .html docs on the libraries of Map and Set.
Here follow the questions and notices.
1. elems :: Set a -> [a]
setToList :: Set a -> [a]
These two look like synonyms, but have different comments.
Am I missing something?
2. size :: Set a -> Int
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