Which pattern-matching syntax is better?

question.rb

# Which pattern-matching syntax you think is better in Ruby?
#
# Some background:
#   - https://github.com/katafrakt/noaidi
#   - http://katafrakt.me/2016/02/13/quest-for-pattern-matching-in-ruby/
#   - http://katafrakt.me/2016/05/24/refactoring-rails-with-noaidi/


# Syntax 1:

Noaidi.match open_file(path), {
  [:ok, File]         => ->(file) { process_file(file) },
  [:error, Exception] => ->(ex) { handle_file_opening_exception(path, ex) }
}
# or
Noaidi.match open_file(path), {
  [:ok, File]         => lambda {|file| process_file(file) },
  [:error, Exception] => lambda {|ex| handle_file_opening_exception(path, ex) }
}

# Pros:
#  - close to syntax from other languages, eg. Elixir
# Cons:
#  - Hackish Hash syntax
#  - Some editors don't like it (emacs)

# Syntax 2:
Noaidi.match open_file(path) do |m|
  m(:ok, File)         { |file| process_file(file) },
  m(:error, Exception) { |ex| handle_file_opening_exception(path, ex) }
}

# Pros:
#  - Using natural Ruby idiom (block)
#  - No duplicate rockets/arrows or unnecessary lambda keyword
#  - dry-transaction uses similar syntax (http://dry-rb.org/gems/dry-transaction/basic-usage/)
# Cons:
#  - I'm not entirely sure it's possible to implement
#  - adds some clutter

Syntax 2 👍

Syntax 2 as well

Syntax 2