• Ellery Newcomer (3/3) Mar 13 2010 anyone know of a good (or any) syntax for an empty aa
• bearophile (12/13) Mar 13 2010 Unfortunately "null" suffices where the function that receives knows the...
• Philippe Sigaud (10/13) Mar 13 2010 To associate a list of key/value pairs into one AA?
• bearophile (4/7) Mar 13 2010 Sorry, I have probably not understood your question.
• Ellery Newcomer (5/12) Mar 13 2010 No, you hit it on the head. Here's the kind of thing I was after:
• bearophile (4/5) Mar 14 2010 I don't understand the question, sorry.

Ellery Newcomer <ellery-newcomer utulsa.edu> writes:

anyone know of a good (or any) syntax for an empty aa

impetus:

auto aa = reduce!(g)(emptyaa, lst);

bearophile <bearophileHUGS lycos.com> writes:

Ellery Newcomer:

 anyone know of a good (or any) syntax for an empty aa

Unfortunately "null" suffices where the function that receives knows the type
of the AA it will receive. But I don't like this, a more typed style can be
less bug prone.

So you can give a type to null:
cast(int[string])null

I have created a bit shorter template:
AA!(string, int)

But it doesn't gain much.

Something similar can be used for dynamic arrays:
cast(int[])null
With dynamic arrays you can also use (that I don't like) "null" and even the
special []

Bye,
bearophile

Philippe Sigaud <philippe.sigaud gmail.com> writes:

On Sat, Mar 13, 2010 at 20:17, Ellery Newcomer
<ellery-newcomer utulsa.edu>wrote:

 anyone know of a good (or any) syntax for an empty aa

 impetus:

 auto aa = reduce!(g)(emptyaa, lst);

To associate a list of key/value pairs into one AA?

I use .init, but AA in general have become buggy for the past few releases.

auto aa = reduce!g((V[K]).init, lst); // this used to work, I think

But, as I said, it has become quite buggy recently:

auto aa = (int[string]).init; // empty AA?
aa["abc"] = 3; // error, no operator [] overload for
AssociativeArray!(string, int). I mean, come on.


Philippe

bearophile <bearophileHUGS lycos.com> writes:

Ellery Newcomer:
 anyone know of a good (or any) syntax for an empty aa
 impetus:
 auto aa = reduce!(g)(emptyaa, lst);

Sorry, I have probably not understood your question.

Bye,
bearophile

Ellery Newcomer <ellery-newcomer utulsa.edu> writes:

On 03/13/2010 07:20 PM, bearophile wrote:
 Ellery Newcomer:
 anyone know of a good (or any) syntax for an empty aa
 impetus:
 auto aa = reduce!(g)(emptyaa, lst);

 Sorry, I have probably not understood your question.

 Bye,
 bearophile

No, you hit it on the head. Here's the kind of thing I was after:

auto g = reduce!("a[b]=1,a")(cast(int[int]) null, [1,2,3,4]);

Works fine. The one-liner probably isn't worth it, but I think it's 
pretty funny. What does this do to Walter's arguments concerning nonnull?

bearophile <bearophileHUGS lycos.com> writes:

Ellery Newcomer:
What does this do to Walter's arguments concerning nonnull?<

I don't understand the question, sorry.

Bye,
bearophile