soveran/clap

Command line argument parsing

clap's Issues

option aliases and regular expressions

How to do option aliases?

CLAP.run ARGV,
  '-o' => lambda { ... }
  '--output' => lambda { ... }

Where both lambdas are the same is redundant. Of course we could create a variable for it:

output_opt = lambda { ... }

CLAP.run ARGV,
  '-o' => output_opt
  '--output' => output_opt

But perhaps an option array could be supported?

CLAP.run ARGV,
  ['-o', '--output'] => lambda { ... }

Also, I wonder if the option itself could be a regular expression?

CLAP.run ARGV,
  /=/ => lambda { |opt| k, v = opt.split('='); options[k] = v }

I really love the simplicity of this library, btw, so maybe these ideas are not useful enough to warrant the additional complexity. But I figure they are worth some thought.

Clap w/ Help?

I'm wondering how Clap might be extended to support standardized command line help output:

Clap.help "Usage: #{$0} [options]",
  "-a" => "explain a"
  "-b" => "explain b"

Clap.run ARGV,
  "-a" => lambda { |param| ... },
  "-b" => lambda { ... }
  "-h" => Clap.help

?

any object that has #call

Instead of just accepting lambdas, CLAP could be made more flexible by accepting any object that has a #call method. Basically replace:

arity = [flag.arity, 0].max

with:

flag  = flag.method(:call) unless Proc === flag
arity = [flag.arity, 0].max

clap sub-command support?

@soveran Could Clap provide subcommand support like the features in git.
For example:

if I do git add, it will print out help message

Nothing specified, nothing added.
Maybe you wanted to say 'git add .'?

Then I can do git add some_files to add files

To support this feature, maybe clap should support various number of arguments for each flag?