Le mercredi 20 avril 2016 à 16:22 +0100, Didier Verna a écrit :
> Milan Bouchet-Valat <[email protected]> wrote:
> 
> > 
> > OTOH, short-circuit operators are in limited number (&& and ||).
> > Packages authors cannot create new ones without the user knowing
>   Do you mean it's possible to create new short-circuit operators ?
No, precisely that it's not possible, so we don't need a special syntax
like @.

Regards

> > 
> > Yes. For example, DataFrames.jl and DataFramesMeta.jl provide
> > functions like where(), by() and aggregate() both in function and
> > macro forms.  The former takes a function, while the latter offers
> > a
> > convenience syntax which creates a function under the hood.
> > 
> > See in particular this section:
> > https://github.com/JuliaStats/DataFramesMeta.jl#operations-on-group
> > eddataframes
>   Thanks.
> 
> 
> > 
> > I don't think that's possible, as the short-circuit behavior of &&
> > means it does not evaluate its second operand if the first one is
> > false. So it cannot be a standard function.
>   Sure. It would have to be built-in.
> 

Reply via email to