class R2CEnvironment

# File lib/r2cenvironment.rb, line 52
def _get(name)
  @env.each do |closure|
    return closure[name] if closure.has_key? name
  end

  raise NameError, "Unbound var: #{name.inspect} in #{@env.inspect}"
end

# File lib/r2cenvironment.rb, line 10
def add(id, type, depth = 0)
  raise "Adding illegal identifier #{id.inspect}" unless
    Symbol === id
  raise ArgumentError, "type must be a valid Type instance" unless
    Type === type

  @env[depth][id.to_s.sub(/^\*/, '').intern][TYPE] = type
end

# File lib/r2cenvironment.rb, line 19
def depth
  @env.length
end

# File lib/r2cenvironment.rb, line 24
def extend # override
  @env.unshift(Hash.new { |h,k| h[k] = [] })
end

# File lib/r2cenvironment.rb, line 28
def get_val(name)
  self._get(name)[VALUE]
end

# File lib/r2cenvironment.rb, line 32
def lookup(name)
  # HACK: if name is :self, cheat for now until we have full defn remapping
  return Type.fucked if name == :self

  return self._get(name)[TYPE]
end

# File lib/r2cenvironment.rb, line 43
def scope
  self.extend
  begin
    yield
  ensure
    self.unextend
  end
end

# File lib/r2cenvironment.rb, line 39
def set_val(name, val)
  self._get(name)[VALUE] = val
end