Why to have properties to sort or duplicate arrays ?

[Pierre Renié]

Derek Parnell Wrote:

> On Sat, 27 Jan 2007 18:00:10 -0500, Pierre Renié wrote:
> 
> > Hello,
> > To me, reading a field or a property should not modify the object.
> > The problem is that just an access to the properties 'reverse' 
> > or 'sort' are modifying my array. These 2 properties should be
> > method instead.
> > 
> > I think that the property 'dup' should be a method too, because
> > 'dup' is not a value of my Array object, it does something.
> 
> Yes, this is a significant design mistake that has always been with us.
> 
> I suspect it came about with the desire to make properties easy to create
> and use, but as a consequence, D properties aren't as useful as they could
> be. They are certainly a good thing but still not as good as they could
> have been.
> 
> I believe that a 'get' Property should return a value without changing the
> entity that owns the value. 
> 
> I don't have an issue with the .dup property in this regard as it returns a
> copy of the entity; however it is not built-in to all datatypes, just
> arrays.
> 
> But .sort and .reverse should just return a copy of the data, sorted or
> reversed respectively.
> 
> I'm pretty sure that Walter will not be changing this or improving the
> Property concept any time soon though. So use this idiom instead ...
> 
>    (sorted_data = data.dup).sort;
>    (reversed_data = data.dup).reverse;
> 
> -- 
> Derek Parnell


I don't think there is a need to change the property concept. Just deprecate the properties 'sort', 'reverse' and 'dup', and create methods instead.