Some thoughts

[JoshCheek]

• In spec/spec_helper.rb maybe add $VERBOSE = nil so you aren't spammed with warnings
• In general, you can make the syntax a lot terser like this:

  -        value =
  -          case Dio.attribute(alice)
  -          in { name: /^A/, age: 30..50 }
  -            true
  -          else
  -            false
  -          end
  -
  +        value = (Dio.attribute(alice) in { name: /^A/, age: 30..50 })

• Ultimately this is going to hit an issue where, wanting to match things with #=== are going to create problems. I looked through the C code, and there isn't a way to interject between them. Eg consider p((Dio.dynamic(1) in { succ: { succ: { succ: Integer } } })), for that Integer to match, it requires that Dio[3].deconstruct_keys([:succ]) returns {succ: 4}, where 4 is an integer, and not a Dio::Forwarders::BaseForwarder, because it will not delegate the class lookup, thus it will not consider the wrapped integer to be an integer:
  
• And you can't extend such objects b/c you can't extend integers
• And you can't refine them, b/c the Ruby C code doing the pattern matching won't see the refinement
• So you can only actually implement it with a monkey patch: