Re: [Haskell-cafe] Value-weak hash tables in Haskell ?

2013-08-10 Thread Trevor L. McDonell
This paper explains how to implement them and gives example code:

http://community.haskell.org/~simonmar/papers/weak.pdf


I'm not aware of a package that does it for you, but I implemented one as part 
of my own work so that may be able to provide another example.


Cheers,
-Trev


On 11/08/2013, at 6:03 AM, Alessandro Vermeulen  
wrote:

> There is supposed to be some weak hash map implementation somewhere.
> 
> However, if you can't find it you can easily create it yourself. However, you 
> will need to use the map in IO so I suggest that you use the hashtables[1] 
> package in combination with the weak pointers mentioned by Erik.
> 
> - Alessandro
> 
> [1]: http://hackage.haskell.org/package/hashtables
> 
> On 10 aug. 2013, at 21:08, Erik Hesselink  wrote:
> 
>> I'm not sure, but there are weak pointer [0], though I have never used them.
>> 
>> Erik
>> 
>> [0] 
>> http://www.haskell.org/ghc/docs/latest/html/libraries/base/System-Mem-Weak.html
>> 
>> On Sat, Aug 10, 2013 at 7:13 PM, Aleksey Uymanov  wrote:
>>> Hello, haskellers.
>>> 
>>> Is there any package implementing magic hash tables weak in value? I
>>> mean when the value is garbage collected, then this key+value
>>> authomatically removes from the hash table.
>>> 
>>> --
>>> Aleksey Uymanov 
>>> 
>>> ___
>>> Haskell-Cafe mailing list
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>>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>> 
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Re: [Haskell-cafe] Value-weak hash tables in Haskell ?

2013-08-10 Thread Alessandro Vermeulen
There is supposed to be some weak hash map implementation somewhere.

However, if you can't find it you can easily create it yourself. However, you 
will need to use the map in IO so I suggest that you use the hashtables[1] 
package in combination with the weak pointers mentioned by Erik.

- Alessandro

[1]: http://hackage.haskell.org/package/hashtables

On 10 aug. 2013, at 21:08, Erik Hesselink  wrote:

> I'm not sure, but there are weak pointer [0], though I have never used them.
> 
> Erik
> 
> [0] 
> http://www.haskell.org/ghc/docs/latest/html/libraries/base/System-Mem-Weak.html
> 
> On Sat, Aug 10, 2013 at 7:13 PM, Aleksey Uymanov  wrote:
>> Hello, haskellers.
>> 
>> Is there any package implementing magic hash tables weak in value? I
>> mean when the value is garbage collected, then this key+value
>> authomatically removes from the hash table.
>> 
>> --
>> Aleksey Uymanov 
>> 
>> ___
>> Haskell-Cafe mailing list
>> [email protected]
>> http://www.haskell.org/mailman/listinfo/haskell-cafe
> 
> ___
> Haskell-Cafe mailing list
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Re: [Haskell-cafe] Value-weak hash tables in Haskell ?

2013-08-10 Thread Erik Hesselink
I'm not sure, but there are weak pointer [0], though I have never used them.

Erik

[0] 
http://www.haskell.org/ghc/docs/latest/html/libraries/base/System-Mem-Weak.html

On Sat, Aug 10, 2013 at 7:13 PM, Aleksey Uymanov  wrote:
> Hello, haskellers.
>
> Is there any package implementing magic hash tables weak in value? I
> mean when the value is garbage collected, then this key+value
> authomatically removes from the hash table.
>
> --
> Aleksey Uymanov 
>
> ___
> Haskell-Cafe mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/haskell-cafe

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