What are the semantics of the span in de::error?

[konstin]

Would it be possible to add to the documentation what the semantics of the Option<Range<usize>> are that toml::de::Error::span() returns? Is it a char offset or a byte offset, and under what conditions will it be None? I want to integrate linting of toml files into our diagnostics system and it would be great to have clarity over how these indices behave we utf-8 content.

[epage]

Is it a char offset or a byte offset

It is documented as the index into the document. That would be a byte offset.

under what conditions will it be None

• If you deserialize from a Document, all span information is lost
• If you deserialize from a &str, then we should (nearly) alway have a span. Any missing span is more likely to be a bug.

[konstin]

It is documented as the index into the document. That would be a byte offset.

Thanks! I unfortunately have encountered a lot of different things people mean by index, so this helps clarifying.

I've opened #558 to make this visible for everybody

[epage]

Thanks! I unfortunately have encountered a lot of different things people mean by index, so this helps clarifying.

Within rust code for the &str type, there is one canonical meaning