The `help` subcommand can now accept other subcommands as arguments to
display their help message. This is similar to how many other CLIs
already perform. For example:
```
$ myprog help mysubcmd
```
Would print the help message for `mysubcmd`. But even more, the `help`
subcommand accepts nested subcommands as well, i.e. a grandchild
subcommand such as
```
$ myprog help child grandchild
```
Would print the help message of `grandchild` where `grandchild` is a
subcommand of `child` and `child` is a subcommand of `myprog`.
Closes#416
Tons of code has been moved into functions, deduplicated, made much
easier to read, maintain, and understand. Comments still need to be
added, but that will happen shortly. Modules have also been moved around
to follow Rust conventions and best practices.
All functionality remains exactly the same
* unknown subcommand message altered to use similar language as is used
everywhere around clap. Namely, we say 'invalid' instead of 'unknown'
* 'did-you-mean' message separator changed from '. ' to '\n\t'
Related to #103
That way, it will run on travis as well, which comes with python 2
by default, and just doesn't have python 3 pre-installed.
It would probably take to much time to install, especially considering
it's super easy to have to script work in both worlds.
There now is a single method which deals with formatting the
'did-you-mean' message, supporting different styles to cater all the
various needs that have arisen thus far, with enough potential to be
easily extended in future through a little helper-enumeration whose
variants can possibly take values.
*NOTE*: We might still want to have a look at where the did-you-mean
message should be located for best effect.
Related to #103
Long arguments now have a special case when saying they are unknown, as
we will match it against all known long flags and suggest the best match
to be used instead.
TODO: refactor to just write a suffix with did-you-mean information.
Related to #103
If an argument is not understood as subcommand, but has a
high-confidence match in the list of all known subcommands, we will use
this one to print a customized error message.
Previously, it would say that a positional argument wasn't understood,
now it will say that a subcommand was unknown, and if the user meant
`high-confidence-candidate`.
If the argument doesn't sufficiently match any subcommand, the default
handling will take over and try to treat it as positional argument.
* added dependency to `strsym` crate
* new `did_you_mean` function uses `strsim::jaro_winkler(...)` to look
for good candidates.
Related to #103
* assure `make test` works on OSX as well
* simplified entire makefile, by basically removing sed invocations to
manipulate the Cargo.toml file under source control.
* *works for me* predicate
This should probably be tested on another system as well, just to be
sure it makes sense for everyone.
Breaking Change
Instead of requiring a Vec<&str> for various Arg::*_all() and
Arg::possible_values() methods this
commit now requires a generic IntoIterator<Item=AsRef<str>> which allows
things such as constant arrays. This change requires that any
Arg::*_all() methods be changed from vec!["val", "val"] -> let vals =
["val", "val"]; some_arg.possible_values(&vals) (or vals.iter()).
Closes#87
