Tricky semantics of ranges & potentially numerous Phobos bugs

[Jonathan M Davis]

On Tuesday, October 16, 2012 10:58:23 David Gileadi wrote:
> On 10/16/12 10:28 AM, Jonathan M Davis wrote:
> > Any range is free to violate this, but because range-based functions are
> > free to rely on it, such ranges risk not working correctly with many
> > range-based functions and must be used with caution.
> 
> As a D dabbler, it seems wrong to me that a built-in range like byLine,
> which is often used in example code, should have weird side effects with
> the built-in methods in std.algorithm. IMO this needs to be fixed one
> way or another, and a mere documentation change is likely not enough for
> casual D users.

ByLine needs to do what it does for performance reasons, so its implementation 
makes a lot of sense, and it really wouldn't make sense for it to do what 
would be necessary to make it work as a normal range (since that would mean 
allocating a new buffer for every line), so if the fact that it's likely to be 
used and then misused by newbies is a big problem, then that's a strong 
argument for making it just use opApply rather than being a proper range. I 
certainly don't think that it makes sense to change how ranges work in general 
just to better support ByLine's weirdness. it would be far too restrictive to 
do so.

- Jonathan M Davis