grammar Function
  include Statement


  rule more_typed_args
    (comma typed_arg )* {
      captures(:typed_arg).collect{|u| u.value }
    }
  end

  rule typed_argument_list
    (left_parenthesis typed_arg? more_typed_args right_parenthesis){
        args = [ ]
        args << capture(:typed_arg).value if capture(:typed_arg)
        args += capture(:more_typed_args).value if capture(:more_typed_args)
        args
        }
  end

  rule call_site
    (basic_expression "." name_expression  argument_list space?) {
      Ast::CallSiteExpression.new(capture(:name_expression).to_str ,
                          capture(:argument_list).value ,
                          capture(:basic_expression).value )
    }
  end

  rule function_definition
    keyword_def name:function_name  parameter_list  newline expressions_end  newline
  end

  rule parameter_list
    left_parenthesis parameter_list:( name:parameter?  (comma name:parameter)* ) right_parenthesis
  end

  root call_site
end