Re: [Factor-talk] Specializing new?

[John Benediktsson]

Well, when you specify ``M: no-news``, you are telling the system to
dispatch off an instance of the ``no-news`` class.

So this works as you expect in your example:

IN: scratchpad T{ no-news } new .
T{ no-news f "same one" }

That's because ``no-news`` is a tuple-class:

IN: scratchpad no-news tuple-class? .
t

But not a ``no-news``:

IN: scratchpad no-news no-news? .
f

Why are you trying to override ``new``? Typically we just provide
constructor words, either automatically generating with ``C: 
no-news`` or using ``new`` or ``boa`` in a  word:

:  ( field -- no-news )
do-something-to-field no-news boa ;

Hope that helps,

John.


On Fri, Aug 19, 2016 at 12:49 PM, fede s  wrote:

> Hi
>
> I see "new" is a generic word, with the regular behavior set as a method
> for object.
> I tried specializing it on other tuple class, but it didn't work.
>
>TUPLE: no-news field ;
>: same-one ( -- t ) T{ no-news f "same one" } ;
>   M: no-news new  drop same-one ;
>
> I expect this:
>
>   no-news new
>   ==>T{ no-news f "same one" }
>
> But i got this:
>   no-news new
>   ==>T{ no-news f f }
>
>   USE: generic
>\ new order
>   ==> { tuple-class no-news }
>
>   no-news \ new lookup-method
>   ==> M\ no-news new
>
> I think there's something wrong here?
>
> 
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[Factor-talk] Specializing new?

[fede s]

Hi
I see "new" is a generic word, with the regular behavior set as a method for 
object.I tried specializing it on other tuple class, but it didn't work.
   TUPLE: no-news field ;   : same-one ( -- t ) T{ no-news f "same one" } ;  M: 
no-news new  drop same-one ;
I expect this:
  no-news new
  ==>T{ no-news f "same one" }

But i got this:  no-news new
  ==>T{ no-news f f }

  USE: generic   \ new order
  ==> { tuple-class no-news }
  no-news \ new lookup-method
  ==> M\ no-news new
I think there's something wrong here?
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Re: [Factor-talk] database integration - foreign keys ?

[Georg Simon]

Thank you. It works.

Am Thu, 18 Aug 2016 08:54:46 -0700
schrieb John Benediktsson :

> If you look through the tests in
> ``basis/db/tuples/tuples-tests.factor`` you can see some uses of
> foreign keys:
> 
> https://github.com/factor/factor/blob/master/basis/db/tuples/tuples-tests.factor
> 
> annotation-schema-foreign-key
> annotation-schema-foreign-key-not-null
> annotation-schema-cascade
> annotation-schema-restrict
> 
> The annotation tuple has a foreign key to the paste table through
> ``paste-id`` with various use-cases tested.
> 
> I'm not sure if we have any good documentation for it (couldn't find
> in my cursory glance), sorry about that.
> 
> Best,
> John.
> 
> 
> 
> 
> 
> On Thu, Aug 18, 2016 at 8:48 AM, Georg Simon 
> wrote:
> 
> > Is there a database type for foreign keys ?
> > Or how can I use foreign keys ?
> >
> > 
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> > https://lists.sourceforge.net/lists/listinfo/factor-talk
> >  


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