Phobos Wish List/Next in Review Queue?

[so]

On Mon, 28 Nov 2011 14:54:07 +0200, Steven Schveighoffer  
<schveiguy at yahoo.com> wrote:

> On Sat, 26 Nov 2011 16:39:38 -0500, Walter Bright  
> <newshound2 at digitalmars.com> wrote:
>
>> On 11/26/2011 5:46 AM, Steven Schveighoffer wrote:
>>> Ranges are not good for reading N bytes from a file
>>> descriptor.
>>
>> Why not? Isn't that exactly what a range is supposed to be good for?
>
> A range has a specific interface:
>
> T front()
> void popFront()
> bool empty()
>
> An input stream has a specific interface:
>
> size_t read(ubyte[] buffer)
> or alternatively:
> ubyte[] read(ubyte[] buffer)
>
> How does one map that interface into an input range?  What is T?  I  
> remember proposals where there was some extra function setFrontBytes, or  
> an additional parameter to front, that allows you to set the number of  
> bytes to read.  This seems like trying to fit a square peg in a round  
> hole.
>
> Now, a range fits very well on top of an input stream with a given  
> context.  That context defines *what* front() is going to return.  For  
> example, the next line of text.
>
> But you still need a well-designed buffered stream interface that a  
> range can use to do its work from.  Streams are not going to be the main  
> interface for most users, but they will be the tools that range  
> developers use to create easily iterated streams.  And when the user  
> wants to read data from a file that has no well-defined T that you can  
> define a range for, the stream should provide all the tools necessary to  
> read that data.
>
> Now, an output stream *does* fit quite well as a range, since an output  
> range's single put method coincides with an ouptut stream's write method.
>
> -Steve

I was absent from range discussions, probably it has been said, sorry.

A ### range means, a structure which implements:

T front()
void popFront()
bool empty()

This matches with:

T peek()
void seek(1)
bool eof()

T is ubyte.

I believe we are asking the wrong questions, first question should be why  
someone would like this simple range interface (3 functions) for streams?
Any use? Yes with these 3 we can do quite many things, not optimal but we  
can. For the real use we need a new range.

T[] get(size_t)
bool put(size_t, T[])
bool seek(size_t)
...

Don't we need a range like this in any case? I doubt we can do much  
without it.