Typed Python?

Jakub Fast kfast at poczta.onet.pl
Thu Jul 8 15:41:45 CEST 2004



Jacek Generowicz wrote:

> Ville Vainio <ville at spammers.com> writes:
> 
> 
>>>>>>>"Jakub" == Jakub Fast <kfast at poczta.onet.pl> writes:
>>
>>    >> Currying:                     lambda x,y : f(x,y,1,2)
>>    Jakub> lambda x: lambda y: f(x,y,1,2)?
>>
>>    Jakub> but then
>>    Jakub> (lambda x: lambda y: f(x,y,1,2))(3, 4)
>>
>>    Jakub> won't work.
>>
>>Of course it won't. It's the difference b/w taking 1 and 2 parameters.
> 
> 
> Which is pretty much the point of currying.
> 
> 
>>(lambda x: lambda y: f(x,y,1,2))(3)(4)
>>
>>will work.
>>
>>I guess you will see that e.g in haskell
>>
>>f 1 2 
>>
>>does exactly this:
>>
>>((f 1) 2 )
>>
>>    Jakub> so much for currying?
>>
>>Well, no.
> 
> 
> Well, yes.
> 
> In Haskell, both
> 
>     f 1
> 
> and
> 
>    f 1 2
> 
> will work, while in Python you have to install the plumbing yourself
> every time.
> 

which is exactly what I meant.... :) With lambda x,y you can't just 
curry the function. You can with lambda x: lambda y:, but then you can't 
do regular application with it.

however, do take a look at 
http://www.sourcekeg.co.uk/www.python.org/peps/pep-0309.html
which is getting in for 2.4 (?)

k




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