From: cldwalker <gabriel.horner@...>
Date: 2009-10-06T03:30:12+09:00
Subject: Re: method_missing for command shell?

On Oct 5, 8:33 am, Roger Pack <rogerpack2...@gmail.com> wrote:
> Hi all.  My bash-fu is a little bit lacking, so here's my question.
>
> I'm wondering if anybody knows of a shell that can be programmed to
> "guess" what you meant when you type in a command errantly, like (kind
> of a bad example, but...)
>
> $ git dif
>
> (it runs git dif, fails, then, in method_missing style, I can tell it
> "oh what I always means when I run git dif is git diff" so it correct
> its for me and runs it).
>
> Any pointers on where to go there?

I'm writing a ruby command/task execution gem which could allow for
easy ruby wrapping of system commands and method_missing-fu for
subcommands: http://github.com/cldwalker/boson

I already do subcommand method_missing with boson, not for guessing
but for smart aliasing: http://github.com/cldwalker/irbfiles/blob/master/boson/commands/boson_method_missing.rb#L10-25

Here's how you could define a simple Boson library that wraps git
subcommands:

module Git
  %w{add checkout diff rm merge pull push}.each do |e|
    define_method(e) do |*args|
      system('git', e, *args)
    end
  end
end

With boson you would be able to execute these subcommands from the
commandline or irb as follows:

bash> boson git.diff
irb>> git.diff

With the above method_missing library you could execute these as git.d
or git.dif

Unfortunately Boson isn't ready yet. Hopefully within the week. In the
mean time you could take that example
module and use it within irb:

def git
  @git ||= Object.new.extend Git
end

class << git
  def method_missing(meth, *args, &block)
    if !(meths = Git.instance_methods.sort.grep(/^#{meth}/)).empty?
      send(meths[0].to_sym, *args, &block)
    else
      super
    end
  end
end