Return partial RSS feeds, rss_loose feature, resolves #22

[msjyoo]

Hello,

Here is the pull request for the partial RSS feeds feature.

• Changed struct signatures using conditional compilation
• Changed struct impl using conditional compilation
• Added feature flag rss_loose to activate the changes to preserve backwards compatibility
• Modified tests so that error tests are ignored since activation of feature flag suppresses errors
• Added the rss_loose feature flag to the test routine
• Documented the changes in README and rustdoc
• Added a README Contributors section, and added myself

One thing I'm concerned about is I've had to use the feature flag #![feature(stmt_expr_attributes)] to be able to get enough control over the compiler to implement these changes, so currently this patch only works for the nightly branch until that feature is un-gated. So it might be a better idea to cook this patch until then.

Still, others might find this useful regardless by leaving it here.

Please review and comment / merge.

Thanks!

[msjyoo]

#22

[frewsxcv]

I'm not planning on merging anything that breaks compatibility with stable or beta.

That said, I think you should be able to replace most of your stmt_expr_attributes usages (which is unstable) with cfg! (which is stable) without too much effort.

Thanks for the pull request!

[frewsxcv]

Another resource: https://doc.rust-lang.org/std/macro.cfg!.html

[msjyoo]

@frewsxcv I've tried that of course ;) But, using if cfg!() is still indicating to the compiler that I want both if / else sections compiled, and of course since this is a type changing conditional compilation, it produces an error (since both cases has to be compiled, before one being optimised away by the true / false constant if). Took me a while to figure out that one :P

[msjyoo]

@frewsxcv I understand not accepting patches that break stable compatibility, but I'd like to leave this open in case anyone else comes across the same problem as mine (and willing to use the nightly) and also for the time when the stmt_expr_attributes becomes stable.

[msjyoo]

Tracking issue here: rust-lang/rust#15701

[jameshurst]

This has been resolved by #24.