Idea: Allow flags to take boolean values

Suppose I have a flag like

val verbose by option().flag()

which can be enabled / set to true by passing --verbose on the command line. Then sometimes, e.g. when using a UI frontend for a CLI tool where a “verbose” option can be set to “true” or “false” in a form, it would be slightly more convenient to simply pass on that boolean value to the clikt option like --verbose=${boolean_from_ui} which expands to either --verbose=true or -verbose=false, instead of implementing logic to use --verbose if the UI parameter is true, and use an empty string / nothing if the UI parameter is false.

So, would it be feasible to make flag options allow to take a boolean-ish value? I realize that in some cases like with a flag called “on” allowing something like --on=off sounds odd; but then again you’d not have to use that syntax.

[sschuberth]

No, I’m not aware of existing CLI tools that work that way out of my head. I’m trying to push innovative features to clikt 😉 That said, JCommander almost supports something like that, with its boolean options with an arity of 1, but then using no value for the options does not work anymore.

[sschuberth]

You’re right, with all the other features that clikt already supports, I also do not see a way to implement this unambiguously. Thanks for evaluating this idea together with me, but it seems fair to me to close this one.