What is the recommended dynamic array type in D? So far I found Array (specifically Array!string, as I need a dynamic array of strings), but my example program crashes:

https://gist.github.com/ivoras/2d7737c214c3dc937c28

The crash is at line 20:

core.exception.AssertError@/usr/include/dmd/phobos/std/container/array.d(334): Assertion failure
----------------
./markov() [0x80fbfd1]
./markov(uint std.container.array.Array!(immutable(char)[]).Array.Payload.insertBack!(immutable(char)[]).insertBack(immutable(char)[])+0x6f) [0x80fa997]
./markov(uint std.container.array.Array!(immutable(char)[]).Array.insertBack!(immutable(char)[]).insertBack(immutable(char)[])+0x36) [0x80fa866]
./markov(_Dmain+0x167) [0x80d7ce7]

This is on DMD32 D Compiler v2.067.1

I would just use a regular `string[]` array...

On Thursday, 14 May 2015 at 12:46:48 UTC, Adam D. Ruppe wrote:
> I would just use a regular `string[]` array...

Is it resizable? Somehow I didn't get that impression from the docs. Apparently it doesn't even have an "insert" method: http://dlang.org/phobos/std_array.html .

On Thursday, 14 May 2015 at 13:26:27 UTC, ivoras wrote:
> On Thursday, 14 May 2015 at 12:46:48 UTC, Adam D. Ruppe wrote:
>> I would just use a regular `string[]` array...
>
> Is it resizable? Somehow I didn't get that impression from the docs. Apparently it doesn't even have an "insert" method: http://dlang.org/phobos/std_array.html .

----
string[] arr;
arr ~= "Foo";
arr ~= "Bar";

writeln(arr, ':', arr.length);
----

It's all built in. ;)

A nice article: http://dlang.org/d-array-article.html
and the language reference: http://dlang.org/arrays.html

On Thursday, 14 May 2015 at 13:26:27 UTC, ivoras wrote:
> Is it resizable?

You can append with the ~= operator and size down by slicing it.

> Apparently it doesn't even have an "insert" method: http://dlang.org/phobos/std_array.html .

http://dlang.org/phobos/std_array.html#insertInPlace

is the one you'd use for that.

On Thursday, 14 May 2015 at 12:42:01 UTC, ivoras wrote:
> https://gist.github.com/ivoras/2d7737c214c3dc937c28
>
> The crash is at line 20:
>
> core.exception.AssertError@/usr/include/dmd/phobos/std/container/array.d(334):
[...]
>
> This is on DMD32 D Compiler v2.067.1

Seems to be fixed in git head.

On Thursday, 14 May 2015 at 13:50:17 UTC, Adam D. Ruppe wrote:
> On Thursday, 14 May 2015 at 13:26:27 UTC, ivoras wrote:
>> Is it resizable?
>
> You can append with the ~= operator and size down by slicing it.
>
>> Apparently it doesn't even have an "insert" method: http://dlang.org/phobos/std_array.html .
>
> http://dlang.org/phobos/std_array.html#insertInPlace
>
> is the one you'd use for that.

Ok, string[] and ~= work and it doesn't crash now.

Where would I look for documentation on the "~=" operator? It's not described in http://dlang.org/phobos/std_array.html (though it is mentioned so you need to know what you are looking for before you find it...).

What would be the difference between Array!string and string[] ?

On Thursday, 14 May 2015 at 20:03:16 UTC, ivoras wrote:
> Where would I look for documentation on the "~=" operator?

http://dlang.org/arrays.html

under the heading "array concatenation"

> What would be the difference between Array!string and string[] ?

Array!string takes ownership of its own memory and frees it when no longer used making it appropriate in cases where you want that optmization. string[] is a slice - pointer plus length combination - into externally managed memory.

On Thursday, 14 May 2015 at 20:03:16 UTC, ivoras wrote:
>
> What would be the difference between Array!string and string[] ?

std.array is used to manipulate or create built-in arrays from various sources (ranges).

For basic needs, you can safely use built-in arrays: http://dlang.org/arrays.html

Concatenation operator (~) is documented here: http://dlang.org/arrays.html#array-concatenation

On Thursday, 14 May 2015 at 20:32:28 UTC, rumbu wrote:
> On Thursday, 14 May 2015 at 20:03:16 UTC, ivoras wrote:
>>
>> What would be the difference between Array!string and string[] ?
>
> std.array is used to manipulate or create built-in arrays from various sources (ranges).
>
> For basic needs, you can safely use built-in arrays: http://dlang.org/arrays.html
>
> Concatenation operator (~) is documented here: http://dlang.org/arrays.html#array-concatenation

Thanks, everyone!

I'm experimenting to get a feel for the language. Do you have a suggestion about this example code: https://goo.gl/F7LCAg to make it more "D-like", idiomatic?