[phobos] UnbufferedFile, or, abstracting the File ranges

[Andrei Alexandrescu]

I think these could be actually byByte and byLine.

Regarding your initial question - generally the range defintion 
"belongs" to the file/container as it has intimate contact with it. You 
could find incidental commonality and exploit it, but conceptually they 
should appear as independent types.


Andrei

Lars Tandle Kyllingstad wrote:
> Well, that would at least mean less work for me. :)
> 
> Which I/O methods should it contain, then, in your opinion?  Would
> 
>         bool read(ref ubyte b);
>         size_t read(ref ubyte[] b);
>         void write(ubyte b);
>         void write(ubyte[] b);
> 
> suffice?
> 
> -Lars
> 
> 
> 
> On Mon, 2010-05-10 at 05:02 -0700, Steve Schveighoffer wrote:
>> Re: byLine and byChunk, I don't think these are a good idea on
>> unbuffered files.
>>
>> For example, your current implementation will be extremely slow.
>> Reading one char at a time is OK on a buffered file, because most
>> times its just a simple fetch of a char from a buffer.  But your
>> implementation reads a single character at a time from the actual file
>> on disk, a very slow operation.
>>
>> I think unbuffered files are good for when you want to handle the
>> buffering yourself, or when you want to pass them to child processes.
>>
>> -Steve
>>
>>
>>
>>
>> ______________________________________________________________________
>> From: Lars Tandle Kyllingstad <lars at kyllingen.net>
>> To: Phobos mailing list <phobos at puremagic.com>
>> Sent: Mon, May 10, 2010 7:40:15 AM
>> Subject: [phobos] UnbufferedFile, or, abstracting the File ranges
>>
>> In the process of designing std.process it has become obvious, as
>> pointed out by Steve, that Phobos needs facilities for unbuffered I/O.
>> To that end, I've started writing an UnbufferedFile type, the current
>> status of which can be seen here:
>>
>>         Code:
>> http://github.com/kyllingstad/ltk/blob/master/ltk/stdio.d
>>         Docs: http://kyllingen.net/code/ltk/doc/stdio.html
>>
>> (Disclaimer: This is very much a work-in-progress, there's lots of
>> stuff
>> that needs to be added yet, and I'd be surprised if there wasn't lots
>> of
>> room for improvement, performance-wise.)
>>
>>
>> Now, while writing this it has kind of annoyed me that I have to write
>> new implementations of the byLine and byChunk ranges.  I've personally
>> found them incredibly useful, so I want them in UnbufferedFile, but
>> the
>> ones in std.stdio are tailored for File.
>>
>> I therefore suggest we try to abstract these ranges, so they can
>> operate
>> on general types that define a set of primitives such as read(),
>> readc()
>> and readln().
>>
>> Are there problems with this?  Any comments?
>>
>> -Lars
>>
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