• Ellery Newcomer <ellery-newcomer utulsa.edu> Mar 13 2010
• bearophile <bearophileHUGS lycos.com> Mar 13 2010
• Philippe Sigaud <philippe.sigaud gmail.com> Mar 13 2010
• bearophile <bearophileHUGS lycos.com> Mar 13 2010
• Ellery Newcomer <ellery-newcomer utulsa.edu> Mar 13 2010
• bearophile <bearophileHUGS lycos.com> Mar 14 2010

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:

--0015175883c8a5518a0481b576c4
Content-Type: text/plain; charset=ISO-8859-1

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

--0015175883c8a5518a0481b576c4
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<br><br><div class=3D"gmail_quote">On Sat, Mar 13, 2010 at 20:17, Ellery Ne=
wcomer <span dir=3D"ltr">&lt;<a href=3D"mailto:ellery-newcomer utulsa.edu">=
ellery-newcomer utulsa.edu</a>&gt;</span> wrote:<br><blockquote class=3D"gm=
ail_quote" style=3D"margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(2=
04, 204, 204); padding-left: 1ex;">
anyone know of a good (or any) syntax for an empty aa<br>
<br>
impetus:<br>
<br>
auto aa =3D reduce!(g)(emptyaa, lst);<br></blockquote><div><br>To associate=
 a list of key/value pairs into one AA?<br><br>I use .init, but AA in gener=
al have become buggy for the past few releases.<br><br>auto aa =3D reduce!g=
((V[K]).init, lst); // this used to work, I think<br>
<br>But, as I said, it has become quite buggy recently:<br><br>auto aa =3D =
(int[string]).init; // empty AA?<br>aa[&quot;abc&quot;] =3D 3; // error, no=
 operator [] overload for AssociativeArray!(string, int). I mean, come on.<=
br>
<br><br>Philippe<br></div></div>

--0015175883c8a5518a0481b576c4--

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