A better way to handle empty strings in argument values

[Byron]

Currently it is possible to pass an empty string to arguments defined like this (maybe it's a valid value to all of them):

Arg::new("from-stop")
             .required(true)

On the command-line, it's now possible to pass in an empty string like so:

$ trains shortest-route A ""

I believe it's too far fetched to disallow empty strings in general, but it would be great if I could set a flag (maybe even it's default on) on the Arg type to let the parser handle empty values for me.

This could look like this:

Arg::new("to-stop")
       .allow_empty_values(false)
       .required(true)

If such a feature does not exist on parser level, each client will have to implement its own check.

[kbknapp]

I think this is a valid suggestion. Let me play with an implementation and I'll post back with the solution.

[kbknapp]

I have the initial work on this done, but I'm going to roll it into a larger update tonight since I don't have time to finish it until later today. I'll posy back later today once its complete ;)

[Byron]

Thanks! No reason to hurry though, as I am just playing it safe and used
'stdin' instead of '-' for the final toy project.
And Google.rs will use this capability once available.
On Sun 17 May 2015 at 19:04 Kevin K. notifications@github.com wrote:

I have the initial work on this done, but I'm going to roll it into a
larger update tonight since I don't have time to finish it until later
today. I'll posy back later today once its complete ;)

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#122 (comment).

[kbknapp]

Should be good now :) Use v0.9.1 on crates.io