Consider making the --output argument more universal (particularly robot export & query)

[allenbaron]

Would it be possible to add --output / -o as an argument to robot export as an alias for the --export argument. Most of the other robot commands (report, extract, etc.) use --output so I invariably try it for robot export and forget that it is not there until I get the error (and then have to look it up).

A similar thing happens when I use robot query with the --query argument. I often specify the output path with the -o argument but it is only an accepted input in connection with the --update argument. It is unusual to me that the --query argument takes two strings, the path to the query and the path for the output.

It seems maybe originally the -o option was meant to apply only for ontology output files? The use of -o in robot report does break that pattern though. I imagine it would be possible to implement these changes without altering the current behavior of the functions. robot query would probably be the hardest to fix.

I would offer a fix myself but don't have the bandwidth at this time (and basically no experience with java). This does not need to be high priority since it is primarily an inconvenience.

Thanks!

[balhoff]

@allenbaron I've also been tripped up sometimes by --query taking two arguments, but finally realized it's because you can specify any number of queries on the same command line, each with their own output. It's quite a bit more efficient this way vs. chaining multiple query commands. Maybe robot could be extra smart and pass along the internal triplestore it creates, in addition to the ontology, when query commands are chained.

[allenbaron]

@balhoff Oh man. I had no idea. That is definitely more efficient for running multiple queries. I knew you could do multiple updates because it's described in the documentation but I hadn't seen anything about multiple --query statements with multiple outputs. That does make sense. I guess that does complicate things a bit more for robot query.

I wonder if the documentation page should be updated to reflect this ability? I'm looking again and can't seem to find anything about it.

[jamesaoverton]

I reread the first part of the query doc, and I agree that it's not clear that you can use --query SPARQL RESULT multiple times. A PR to improve https://github.com/ontodev/robot/blob/master/docs/query.md would be appreciated.