Fix boolean options

[denys-duchier]

type=bool is not the way to do boolean options with argparser. I added add_boolean_option and used it to automatically define both --foo and --no-foo options.

[inclement]

This seems quite complicated - would doing it like e.g. http://stackoverflow.com/a/15008806/2469283 be better? It seems to avoid the need for string mangling outside of argparser.

[denys-duchier]

I did it like that at first, but then I realized that the automatically generated help was hard to read. so I added groups for each pair of boolean options. I didn't go the t_or_f way because that's not the canonical way to express boolean options. Also I wanted to preserve existing options such as --allow_download, but also provide the more standard --allow-download. I don't find my code to be complicated at all (but of course YMMV), and it makes declaring boolean options very easy.

[inclement]

The muckery to allow both _ and - was probably the main thing that seemed messy to me. How would you feel about adding just the - versions and not supporting the underscores - I only did it that way in the first place because I wasn't familiar with this convention (I now understand that dashes do seem normal?). At this point, I think it's fine to do a small breaking change like this.

Could you also pep8-style the code, there are just a few things like missing spaces after commas?

[denys-duchier]

if you are ok with the breaking change, then I am even happier. I'll update the PR accordingly.

[denys-duchier]

I made pep8 shut up, but there were lots of issues I wasn't responsible for :-)

[inclement]

No problem, it was just pep8 of the new code I'm worried about, the rest is of course not your problem (actually I have to merge a tshirtman commit to fix them).

[denys-duchier]

they are all fixed in my PR (for toolchain.py)

[inclement]

Oh, in that case thanks even more!

[inclement]

I had a query on #kivy-dev, but I guess I missed you. It was:

The boolean option one seems fine, but how would you feel about stripping it to be simpler? There isn't actually really a need to support multiple args doing the same thing (presumably this stems originally from supporting the underscores?), and I also think that manually messing with the -- prefix is unnecessary.

If that sounds reasonable to you, I can make those changes myself on merging, if you don't want to bother updating the PR.

[denys-duchier]

ah yes, I went to sleep. multiple names are still needed if you want to provide both long and short option names. I think argparse already does replace - in the option name with _ to get the default dest, so that could be taken out. The case for no versions computed from names could be simplified if you are willing to live with --foo_bar (which someone could very well choose to do) yielding --no-foo_bar.

tell me what you think. right now I have to go teach a class... I'm late :-/

[inclement]

I've merged this, thanks again for it.

Regarding the stuff about argument formatting, I'll leave it for now but I think aim to consolidate everything at some point - right now there are also problems like ignored arguments and inconsistent argument names, so there should definitely be a break to fix it (and then after that keep it stable).