class Unparser::Emitter::Pair

def colon?
  n_sym?(key) && BAREWORD.match?(key.children.first)
end

def dispatch
  if colon?
    emit_colon
    unless implicit_value_lvar? || implicit_value_send?
      write(' ')
      visit(value)
    end
  else
    visit(key)
    write(' => ')
    visit(value)
  end
end

def emit_colon
  write(key.children.first.to_s, ':')
end

def implicit_value_lvar?
  n_lvar?(value) && value.children.first.equal?(key_value)
end

def implicit_value_send?
  children = value.children
  n_send?(value) \
    && !key_value.end_with?('?') \
    && !key_value.end_with?('!') \
    && children.fetch(0).nil? \
    && children.fetch(1).equal?(key_value) \
    && children.at(2).nil?
end

def key_value
  key.children.first
end