Mechanism which combines 'adding' and 'positionalList' behavior

[JakeWharton]

I want to parse a command which takes a series of key/value pairs. From my experiments, adding gives me the ability to accumulate multiple arguments and positionalList gives me the ability to consume the next two arguments after a flag. There doesn't appear to be a way to combine these so that I can accomplish something like the following:

./whatever --kv hey there --kv these are --kv multiple values

Which would somehow allow combining the positionalList and adding behavior into a List<List<String>>.

[xenomachina]

Yeah, positionalList is not intended to be associated with an option, so it won't do what you're trying to do here.

There is a way to do what you want using the internal option method. I almost made this method public, but ended up making it internal before the initial release, as its API is kind of ugly and error-prone, and I didn't want to paint myself into a corner by making it public.

I've also been considering cranking down its power a bit before making it public. Most arg parsing APIs have essentially 3 kinds of options: 0-arg, 1-arg, and 0/1-args (aka non-greedy 1-arg -- see #8 ). Right now options actually lets an option consume an arbitrary number of arguments, and decide to stop based on the argument values (with a look ahead of 1), even though none of the public helpers actually use this ability beyond consuming a single argument.

One idea I've had for changing it to be less error-prone, while still exposing more power than is currently available, is to make the user (of options) specify a fixed argument count. Then for your case you'd state that it takes 2-arguments. (I'd also have to special-case the 0/1 non-greedy case.)

In the meantime, would something like a "putting" method that works like adding but consumes 2 (instead of 1) args and puts the key/value pairs into a Map be good enough for your immediate needs? That would be pretty easy to add, and I think would probably be generally useful.

[xenomachina]

I'm thinking that I'm going to change option to take an argument count (or possibly an argument name list), and make it public. I'm not going to have a chance to work on this for the next week or so, though.

[JakeWharton]

Sorry I've been busy and haven't had a chance to consider either putting or take a look at optional. I'm currently doing key=value and adding which works, so anything that lets me do the two argument things after a flag is excellent.

[xenomachina]

Version 2.0.0 (just released) makes this possible. I've even added an example in the README (it's also in the tests). Search for "putting" in the README.