Ordered options

[perrygeo]

I have a situation where I need to know the order of multiple multi-value options. i.e.

--gamma b 0.95 --sigmoidal-contrast r,g,b 5 0.5 --saturation 120

is different from

--saturation 120 --sigmoidal-contrast r,g,b 5 0.5  --gamma b 0.95

Is there any way to retain the order of the supplied options or is this outside of click's scope? Does anyone have any suggestions for different click-based designs that would accomplish the same task (short of writing a DSL)?

[untitaker]

I think your proposal in mapbox/rio-color#23, plus the first solution (using non-space as delimiter) is much better. A "click-based" design also means to me that it wouldn't violate the strong opinions about semantics that come with Click (e.g. unordered options). Unsurprisingly I happen to agree with those opinions.

What about this DSL:

rio color in.tif out.tif gamma r,g 1.05 saturation 125

This is still unambigous assuming all your filters accept a constant amount of args.

With all that said, you can, in theory, preserve the order by subclassing click.Command and overriding parse_args.

[perrygeo]

@untitaker Thanks for the input - at least I can rest assured that I'm not missing something obvious in the click docs.

Overriding parse_args might be an interesting approach but probably a last resort.

The unquoted DSL approach might work very well, thanks for the suggestion!

[untitaker]

I'll close this then as there's nothing actionable. Good luck.