[phobos] std.base64 replacement

[Shin Fujishiro]

I'm sorry but I respond to a part of your message for now.  I'll post a
reply for the rest later!

Daniel Murphy <yebblies at gmail.com> wrote:
> > Input ranges can only support N-1 conversions in a sane way.  They
> > can read as much items as needed from the 'front' of their underlying
> > source ranges, but can only expose a single item.
> >
> > Similarly, output ranges are restricted to 1-N conversions.
> >
> > Yeah, I know you can work around the problem by caching several items
> > inside a decorator range.  It's done in your code and pretty works. :-)
> > But I think it is showing how ranges are unfit for filtering purposes.
>
> I see that caching may be undesirable in some situations, but this adapter
> (and I assume most others) can be implemented perfectly well without it.
>  It's a flaw in implementation, not a limitation of ranges.

So... how?

To tell a truth, I've tried creating decorator ranges for character code
conversion and zlib decompression, and both required internal caching.
I think it's a limitation of the decorator design.

Perhaps I'm missing something?  Please tell us if you know a way to
implement M:N decorators without caching!


Shin