From: ljjarvis@...
Date: 2015-05-28T14:59:00+00:00
Subject: [ruby-core:69394] [Ruby trunk - Feature #11191] Add #to_h method to	OptionParser

Issue #11191 has been updated by Lee Jarvis.


> This is not acceptable as-is though, because of the design that an OptionParser instance should not be modified (and may be frozen) at parsing.

Yes good point. 

> Currently, you can get a hash by using parse_in_order directly

I noticed that too. This functionality is not exposed though, and I think it should be.

>  the keys will be strings however

I think having strings is better that nothing, but I do think symbols would be better. 

> What you want is a method like this?

Yes exactly. This will remove much of the boilerplate I mentioned above. However, the functionality should be exposed (I'm not sure if your code was suggesting that this is a documentable feature or just a workaround). This is made a little more difficult with the design that an `OptionParser` instance should not be modified at parse time. Do you have any other ideas for a workaround?

----------------------------------------
Feature #11191: Add #to_h method to OptionParser
https://bugs.ruby-lang.org/issues/11191#change-52669

* Author: Lee Jarvis
* Status: Feedback
* Priority: Normal
* Assignee: Nobuyoshi Nakada
----------------------------------------
Simply collecting configuration values is a very popular use for OptionParser. Code like this is quite common:

~~~ruby
config = {}
opts = OptionParser.new do |o|
  o.on "-h", "--host=HOST", "hostname" do |h|
    config[:host] = h
  end
  o.on "-p", "--port=PORT", "port", Integer do |p|
    config[:port] = p
  end
  o.on "-v", "--verbose" do
    config[:verbose] = true
  end
  o.on "-q", "--quiet" do
    config[:quiet] = true
  end
end
opts.parse!
# do something with config values
~~~

This boilerplate is one of the reasons I built Slop: https://github.com/leejarvis/slop

I'd like to add a `to_h` method to OptionParser which returns a Hash containing the switch name and switch argument values. This would reduce the above example to:

~~~ruby
opts = OptionParser.new do |o|
  o.on "-h", "--host=HOST", "hostname"
  o.on "-p", "--port=PORT", "port", Integer
  o.on "-v", "--verbose"
  o.on "-q", "--quiet"
end
~~~

With this example, the output would look something like:

~~~ruby
opts.parse %w(--host localhost --port 8000 --verbose)
puts opts.to_h #=>
  {:host=>"localhost", :port=>8000, :verbose=>true, :quiet=>nil}
~~~

I've attached a patch that implements this functionality in quite a basic way. I'm very keen to hear what others think.



---Files--------------------------------
0001-Add-to_h-method-to-OptionParser.patch (2.97 KB)


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