Support unambiguous arbitrarily ordered flags

[alecthomas]

Support unambiguous arbitrarily ordered flags

[alecthomas]

--help should currently be special cased to work in most locations, but it's possible there are some cases where it doesn't.

That said, I agree. What I would really like to do is be able to specify any flag for any command/subcommand at any point after the command. That is, if "foo" is a flag for command "foo" (ie. foo --foo) then --foo can also be specified to any sub-command of foo. eg. foo bar --foo. Additionally, --help for "bar" should display all ancestor commands and flags.

[xealot]

Agree

[alecthomas]

I'm not 100% sure this is possible in full.

Imagine this definition:

flag := kingpin.Flag("flag", "").String()
cmd := kingpin.Command("cmd" ,"")
arg := cmd.Arg("arg", "").String()
cmdFlag := cmd.Flag("cmdflag", "").String()

Given this command line:

cli --flag cmd

It's not really possible to determine whether the user meant cmd to be an argument to --flag, or the command cmd.

That said, this commit (3c91444) in the v2-unstable branch lets you specify flags at any point after their definition.

So in the example above one could do:

cli cmd --flag=foo --cmdflag=bar

I think that is probably sufficient, so I'm going to close this issue. Let me know what you think.

[xealot]

While this definition is certainly challenging to program a parser for I don't know if it's ambiguous. If the Flag isn't a boolean flag that means it requires an argument so the next token on the stream would be the argument to the flag. This would consume "cmd" in your first example.

If the flag was a boolean it would not consume the next token on the stack and cmd would be interpreted as the subcommand.