Re: Taming constructors?

The trick is that we're amplifying based on the purse identity itself,
rather than creating a separate box object, to be obtained from a purse
only to be amplified.


On Thu, May 8, 2014 at 10:16 AM, Mark S. Miller <[email protected]> wrote:

> The WeakMaps of EcmaScript 6 provide even better support for rights
> amplification. First, they enable the trivial creation of sealer/unsealers:
>
> function makeSealerPair() {
>   var wm = new WeakMap();
>   return def({
>     seal: function(payload) {
>       var box = def({});
>       wm.set(box, payload);
>       return box;
>     },
>     unseal: function(box) {
>       return wm.get(box);
>     }
>   });
> }
>
> Second, WeakMaps support better rights amplification patterns when used
> directly, rather than through the sealer/unsealer abstraction. Compare the
> MintMaker of <
> http://erights.org/elib/capability/ode/ode-capabilities.html#simple-money>
> and <http://research.google.com/pubs/pub40673.html>. The direct use of
> WeakMaps for rights amplification enables the second to avoid the getDecr
> function needed by the first.
>
>
>
>
>
> On Wed, May 7, 2014 at 9:12 PM, Norman Hardy <norm-vN3M59HtaNxWk0Htik3J/[email protected]> wrote:
>
>> I certainly think so. I began to implement the factory in Scheme and was
>> reminded that Scheme lacks efficient synergy or any primitive to build it.
>> http://cap-lore.com/Languages/Scheme/Synergy.html
>> Some languages accidentally build it in, such as C++, OCaml, Smalltalk as
>> part of their class structures.
>> The original 1973 paper by Moriss suggests a simple sealer-unsealed
>> primitive which I have not seen adopted in any wide spread language.
>> Jonathan Rees has a variant of Scheme with efficient synergy.
>>
>> On 2014 May 6, at 18:55 , David Nicol <[email protected]> wrote:
>>
>>
>>
>>
>> On Thu, May 1, 2014 at 9:07 AM, Kevin Reid <kpreid-M/[email protected]> wrote:
>>
>>>
>>> I think that this is not a useful pattern in a capability language
>>>
>>
>> the "factory pattern" is how one does constructors in a capability
>> language, no?
>>
>>
>>
>>
>> --
>>
>> "you are browsing from
>> crawler0-complaints-to-admin.webresearch.pa-x.dec.com on the
>> webresearch.pa-x.dec.com network."-- 1998 snapshot of dynamic page at
>> archive.com
>>  _______________________________________________
>> cap-talk mailing list
>> [email protected]
>> http://www.eros-os.org/mailman/listinfo/cap-talk
>>
>>
>>
>> _______________________________________________
>> cap-talk mailing list
>> [email protected]
>> http://www.eros-os.org/mailman/listinfo/cap-talk
>>
>>
>
>
> --
>     Cheers,
>     --MarkM
>



-- 
    Cheers,
    --MarkM

_______________________________________________
cap-talk mailing list
[email protected]
http://www.eros-os.org/mailman/listinfo/cap-talk