Handle presence/absence of eprint prefix

[nxg]

The BibTeX 'eprint' field may or may not include an 'arXiv:' prefix, and there may or may not be an 'archivePrefix' field.

Proposed solution:

• If the eprint includes 'foo:', then include it
• If not, and if there's an 'archivePrefix' field, use that
• If not, then use 'arXiv:'

It's probably infeasible to do the string matching in bst-language, so this might be a case for another macro in mn2e.cls

[nxg]

This addresses issue #7, but I'd like Keith to comment before closing it. I don't think this functionality can be provided entirely within bst-language (well it might be possible, but it would count as extravagantly arcane if done there).

Keith: if you think this is done, feel free to close.

[nxg]

@keithtsmith , if you think this is done, can you close the issue?

[timj]

I hope this is okay, I can't believe the number of MNRAS papers I see where the reference just says "arXiv preprint" and does not include the actual arXiv identifier (making it useless -- I am assuming all these get caught in the final production stage as I generally see the preprints).

[keithtsmith]

Downloaded, tested, didn't work. None of the eprint fields showed up.

I'm probably doing something stupid or have the wrong things inserted into the .cls . I would attach the minimal working example, but github only seems to allow image attachments. I'll email you both.

[timj]

Before 78ff943 eprint identifiers were explicitly hidden in Journal mode in commit 3b36609. The clickable links take you to the DOI or whatever. Conference proceedings now look like A&C though in that arXiv and DOI identifiers show up. The good news is that ASCL entries from ADS show up correctly with ascl: prefix.