Emit error without line number

[segeljakt]

How do you emit an error which is not tied to a specific line number? For example, "File not found".

[zesterer]

There's not currently a way to do this, unfortunately. It would be relatively trivial to change this though: just make the initial offset field optional, and then wrap the error location code in an if let, I'd think.

[shilangyu]

Does it also mean that it is not possible to generate a report not tied to any source but rather the file itself?

For instance, in my language file names have to be valid identifiers, so I would like to print a ariadne-style error diagnostic if a file name is not that. Is that possible?

[zesterer]

That should be possible, yes: just use an offset pointing at the start of the file and don't include any labels.