accumulating values into a Vec<Vec<String>> ?

[bwo]

I have an ancient python script I'm converting to Rust which enables me to pass options like so:

script -s a b -s c d --foo

where the arguments to -s keep accumulating until another option (anything beginning -, basically) is found, each in its own list, so that in the above invocation the values associated with it would be [["a", "b"], ["c", "d"]]. Is it possible to convince Clap to do something like this?

[sueun-dev]

clap can group these per occurrence. give the arg num_args(1..) so it collects values until the next -flag, plus ArgAction::Append so each -s starts its own occurrence, then read it back with get_occurrences instead of get_many.

ran it on -s a b -s c d --foo (clap 4.6.1):

Arg::new("s").short('s').action(ArgAction::Append).num_args(1..)
// then:
m.get_occurrences::<String>("s").unwrap()
 .map(|o| o.cloned().collect::<Vec<_>>()).collect::<Vec<_>>()

that gives [["a", "b"], ["c", "d"]], and --foo still parses fine since it ends the last group. get_many flattens the same data to ["a", "b", "c", "d"], which is the usual trap here. get_occurrences is the stabilized form of the old grouped_values_of.

[epage]

As for derive, you can look at https://docs.rs/clap/latest/clap/_derive/index.html#field-types to see that Vec<Vec<T>> is handled and what it maps to.

[bwo]

awesome thank you!