sawaken

# run on irb as follows.
# $ irb -r './type0.rb'
# irb> e [:define, :f, [:lambda, [:v], ["+", :v, 1]]]
# irb> e [:f 1]
# => 2
# ...

module Type0
  Environment = Struct.new(:parent, :hash)
  Lambda = Struct.new(:env, :params, :exp)