I totally agree that we should have a consistent formatting for array index expansion.
I had a look to the mjsonrpc code and I found the function parse_array_index_list(...) which does this job.
I have a similar function (adapted form previous code) in odb.cxx called strarrayindex(...) that is designed for the same "consistency" purposes between odbedit and sequencer.

Let me put few points that I noticed:
- mjsonrpc has a very different way to write the full array (no indexes given) while currently sequencer requires "[*]" to do the same (otherwise it only changes the first value of the array)
- currently the sequencer and the underlying ODB calls use two indexes (that are the same if you want to write only one key) so we will need a serious rewriting to allow something like "ODBSET array[1,3,5]"
- if I correctly understood the code, mjsonrpc instead generates a list of indices and then calls an ODB write on each of them. That's not always a good thing, for example if you are writing an array of n parameters on a DAQ 
board you will call the hotlink on that key n times
- in addition to that the sequencer will also have to cope with variable-based indexes like "ODBSET array[$val]", but then how it should parse something like "[$a,1]" or "[$a*]"?

For the very first point I do not see a clean way to do this without breaking the compatibility of existing sequencers or having a difference between the two implementations.
For the others I guess we can find a way out, however that's a major modification so I will put it on my todo list when I can find some free time.
In any case I would propose to merge the two functions, so we have only to maintain a single implementation of the parsing.

I guess it's a good moment to brainstorm about that, let me know what you think

Marco


> > The following all fail with "Cannot find ODB key "<key>""
> > 
> > ODBSET "/Detectors/Det*/Settings/Charge/Bias (V)[*]" 0
> > ODBSET "/Detectors/Det*/Settings/Charge/Bias (V)[0-9]" 0
> > ODBSET "/Detectors/Det*/Settings/Charge/Bias (V)[1]" 0
> > ODBSET "/Detectors/Det*/Settings/Charge/Bias (V)*" 0
> > ODBSET "/Detectors/Det*/Settings/Charge/Bias (V)" 0
> > 
> 
> It would be cool if ODB pattern matching in the sequencer
> were consistent with the ODB pattern matching in the json-rpc
> interface for web pages:
> 
> https://midas.triumf.ca/MidasWiki/index.php/Mjsonrpc#Supported_array_index_syntax
> 
> K.O.