• knjhara (7/7) Mar 12 2006 How about this?
• John Demme (16/28) Mar 12 2006 How would this work with the current syntax? Currently, obj[m .. n] wil...

knjhara <knjhara cc.kyoto-su.ac.jp> writes:

How about this?

foreach( ...; obj[m .. n] )

means

int obj.opSliceApply(m, n, int delegate(...) dg)

It is removed the necessity of making tmpObj(like struct) for opApply;

--
knjhara

John Demme <me teqdruid.com> writes:

knjhara wrote:

 How about this?
 
 foreach( ...; obj[m .. n] )
 
 means
 
 int obj.opSliceApply(m, n, int delegate(...) dg)
 
 It is removed the necessity of making tmpObj(like struct) for opApply;
 
 --
 knjhara

How would this work with the current syntax?  Currently, obj[m .. n] will
return a slice, then run .opApply(delegate...) on the object that the slice
returns.  Your above syntax is inconsistent, as it means the compiler would
ignore a slice operator in this case.

I'd imagine that you'd like this for efficiency reasons, so you don't have
to create a new object (or worse, copy an array or something) in order to
iterate through just a few of them.

If obj is a class of your own design, just make a method .iterSlice(n,m)
which returns a struct which can efficiently iterate your objects.  It's
not as pretty, but it is consistent.

If you're more concerned about D's built-in arrays- don't be.  If you slice
an array, it doesn't immediately copy it.   Iterating through an array
slice with the foreach shouldn't require any memory allocations.

...Or am I way off here?

~John Demme