Expose span in Document

[baszalmstra]

If I read the docs correctly it looks like span is kept private to the crate is there are reason not to expose this information? It would be beneficial to query a document and ascertain where something is in the document to display friendly diagnostics.

[epage]

The priority for implementing span support was for the serde API so that toml 0.6 could retain feature parity with 0.5.

However, in doing so, spans slowed things down by quite a bit. We were able to speed things back up by making spans exclusive to the serde API (see #429). It will take some experimentation and iteration to get span support in the toml_edit API without data corruption, panics, and performance loss.

[dtolnay]

For now, here is a workaround that makes it possible to access the span of an arbitrary node, using only the existing public API of toml_edit. https://play.rust-lang.org/?version=stable&edition=2021&gist=0d457da235449046bd30932a91e45d96

[epage]

I wonder if error reporting is faster or using Spanned. I'm assuming error reporting because it won't recurse.

[epage]

#698 allows access to spans if you parse with an ImDocument as that works around the limitation with exposing spans in Document.

Is that sufficient?

[epage]

Without further feedback, I'm going to consider this resolved. If there is a reason we should re-open this, let us know!