Skip extra property when comparing LocatedSpanEx

[zakcutner]

LocatedSpanEx includes an extra property that is designed for "extra information that can be embedded by the user".

Since PartialEq is derived on LocatedSpanEx, checking equality on two spans involves checking equality on the extra property. This is undesirable as, by definition, the extra information is separate from the input so should not be compared when determining if two input spans are the same.

I have come across this issue as there are several nom combinators which require comparing two inputs, for instance many1. Currently, the only workaround is wrapping the extra information in a trivial struct which always returns true when compared.

I resolve this by instead providing a custom PartialEq implementation for LocatedSpanEx. Whilst doing this, I also fixed a typo within the docs for the extra property and implemented Eq (equivalence relation) on LocatedSpanEx where the generic T allows for this. 😄

I hope this helps, let me know if there are any questions or suggestions!

[progval]

I thought we were already doing that. Thanks!

Could you add a test to avoid regressions in the future?

[zakcutner]

I've added a test to make sure the extra property is not compared for PartialEq

[progval]

Thanks, merged! (be80026 and 887f7b4)

[zakcutner]

Perfect, thanks for getting this merged so quickly 😍

Any idea when this change will get released to crates.io?

[progval]

@fflorent Could you publish a minor release for this?