Given a range with element type char, what's the best way of iterating over it by code-point, without filling an array first?

Related to this: What's the status of std.utf and std.encoding? The comments in std.encoding say that some functions supersede their std.utf counterparts.

On Tue, 20 May 2014 17:59:07 +0000, John Colvin wrote:

> Given a range with element type char, what's the best way of iterating over it by code-point, without filling an array first?
> 
> Related to this: What's the status of std.utf and std.encoding? The comments in std.encoding say that some functions supersede their std.utf counterparts.

Foreach on narrow strings automatically decodes, so it's as simple as:

// assume UTF-8 encoded
char[] myData = ...
foreach (dchar codePoint; myData)
   ...

On Tuesday, 20 May 2014 at 17:59:09 UTC, John Colvin wrote:
> Given a range with element type char, what's the best way of iterating over it by code-point, without filling an array first?
>
> Related to this: What's the status of std.utf and std.encoding? The comments in std.encoding say that some functions supersede their std.utf counterparts.

FWI, Walter just wrote "byDchar", that does what you want:
https://github.com/D-Programming-Language/phobos/pull/2043

It's about to be merged.

On Tuesday, 20 May 2014 at 18:06:09 UTC, Justin Whear wrote:
> Foreach on narrow strings automatically decodes, so it's as simple as:
>
> // assume UTF-8 encoded
> char[] myData = ...
> foreach (dchar codePoint; myData)
>    ...

I think the point of his question is if you have an actual non-array range of chars, in which case foreach does NOT decode. It simply iterates.

On Tuesday, 20 May 2014 at 19:58:17 UTC, monarch_dodra wrote:
> On Tuesday, 20 May 2014 at 17:59:09 UTC, John Colvin wrote:
>> Given a range with element type char, what's the best way of iterating over it by code-point, without filling an array first?
>>
>> Related to this: What's the status of std.utf and std.encoding? The comments in std.encoding say that some functions supersede their std.utf counterparts.
>
> FWI, Walter just wrote "byDchar", that does what you want:
> https://github.com/D-Programming-Language/phobos/pull/2043
>
> It's about to be merged.

Sweet! I was vaguely aware of this but didn't know what the progress was. Thanks :)

In the mean time I hand-rolled my own, but I'm sure Walter's is infinitely better so I'll swap over ASAP.