On 24 March 2013 14:06, Jonathan M Davis <jmdavisProg@gmx.com> wrote:

On Sunday, March 24, 2013 13:55:26 Manu wrote:
> I'd like to clarify some conflicts I've encountered.
>
> TDPL talks about ranges, it mentions random access ranges requiring these
> functions:
>
> T at(int i)
> Range slice(int x, int y)

This is not used by Phobos. I don't know why TDPL uses those. They are not
supported at all and AFAIK never have been.

My mistake; I stumbled upon an article written in 'CDJ#++', which I thought was an exert from TDPL (mixed my browser tabs up) >_<

> Also, forward ranges require:
>
> Range save()
>
> But there is also this function:
>
> Range opSlice()
>
> With no args, handles the syntax 'range[]'. save() and opSlice() with no
> args would appear to be identical.
> Why have both? Which will be used in which cases?

Range opSlice()

is never used by ranges. It's only used by containers when you want to get a
range for them.

So what's the difference between save() and opSlice() though? They appear to be identical regardless... is save() redundant?

If you want to know exactly which functions are supported by ranges, and the
documentation isn't clear enough

This is my point, _there is no documentation_.

just look at the definitions for the range
traits in std.range - isInputRange, isForwardRange, etc. They specify exactly
what a type must do to qualify as each type of range.

I have been, but since I'm just digging, and have no authoritative reference, I am easily confused when I see conflicting or apparently redundant code.

A D user shouldn't have to do this. I encourage a section under Language -> Language Reference on dlang.org, to anyone who is an authority on the topic.