Why Arg::last requires double dash -- even if no other arguments left to parse?

[lnyng]

According to doc here, Arg::last requires -- even if no other arguments left to parse. https://docs.rs/clap/2.33.3/clap/struct.Arg.html#method.last

Is there any strong reason for this feature? This seems quite inconvenient to me. Would really like to have another option to allow omitting the double dash if not right behind another multi-Arg.

By the way, the current help message for Arg::last is also wrong. For this example playground, the usage is shown as

test [--] <cmd>...

but it should actually be

test [-- <cmd>...]

[pksunkara]

It's how the parsing happens. I haven't actually looked at this part since I took over the maintenance, so I am not sure behind the reasons why it is done like this.

[lnyng]

Thanks for the reply. Could you point me to which part of the parsing code it corresponds to? I may take a look and see if it's possible to come up with a pull request.

[pksunkara]

https://github.com/clap-rs/clap/blob/master/src/parse/parser.rs#L152 and surrounding areas. Do check if this is still an issue on the master or not.

[ldm0]

Tracking issue of Arg::Last: #888

The related code is here:

clap/src/parse/parser.rs

Lines 517 to 528 in 50fb4ca

	pos_counter += 1;
	}
	} else if self.is_set(AS::TrailingValues)
	&& (self.is_set(AS::AllowMissingPositional) || self.is_set(AS::ContainsLast))
	{
	// Came to -- and one positional has .last(true) set, so we go immediately
	// to the last (highest index) positional
	debug!("Parser::get_matches_with: .last(true) and --, setting last pos");
	pos_counter = positional_count;
	}
	if let Some(p) = self

It's by design, according to the issue and the code. You can create an issue for discussion. (BTW, I think the behaviour is strange too.)