我需要用 Fortran 程序解析 XML 文件。我正在评估xmlf90 解析器工具，看看它是否对我的需求有用，但我无法让用户手册中的示例问题正常工作。该错误与类型不匹配有关：
pcdata_chunk_handler=pcdata_chunk )
1
Error: Type mismatch in argument 'pcdata_chunk_handler' at (1);
passed REAL(4) to UNKNOWN
我直接从用户手册中复制了示例。这是我的主程序，它调用 xml 解析器：
program inventory
use flib_sax
use m_handlers
type(xml_t) :: fxml ! XML file object (opaque)
integer :: iostat
call open_xmlfile("inventory.xml",fxml,iostat)
if (iostat /= 0) stop "cannot open xml file"
call xml_parse(fxml, begin_element_handler=begin_element, &
end_element_handler=end_element, &
pcdata_chunk_handler=pcdata_chunk )
end program inventory
这是“m_handlers”模块：
module m_handlers
use flib_sax
private
!
public :: begin_element, end_element, pcdata_chunk
!
logical, private :: in_item, in_description, in_price
character(len=40), private :: what, price, currency, id
!
contains !-----------------------------------------
!
subroutine begin_element(name,attributes)
character(len=*), intent(in) :: name
type(dictionary_t), intent(in) :: attributes
integer :: status
select case(name)
case("item")
in_item = .true.
call get_value(attributes,"id",id,status)
case("description")
in_description = .true.
case("price")
in_price = .true.
call get_value(attributes,"currency",currency,status)
end select
end subroutine begin_element
!----------------------------------------------------------------
subroutine pcdata_chunk_handler(chunk)
character(len=*), intent(in) :: chunk
if (in_description) what = chunk
if (in_price) price = chunk
end subroutine pcdata_chunk_handler
!----------------------------------------------------------------
subroutine end_element(name)
character(len=*), intent(in) :: name
select case(name)
case("item")
in_item = .false.
write(unit=*,fmt="(5(a,1x))") trim(id), trim(what), ":", &
trim(price), trim(currency)
case("description")
in_description = .true.
case("price")
in_price = .false.
end select
end subroutine end_element
!----------------------------------------------------------------
end module m_handlers
我解析的“inventory.xml”文件是：
<inventory>
<item id="003">
<description>Washing machine</description>
<price currency="euro">1500.00</price>
</item>
<item id="007">
<description>Microwave oven</description>
<price currency="euro">300.00</price>
</item>
<item id="011">
<description>Dishwasher</description>
<price currency="swedish crown">10000.00</price>
</item>
</inventory>
如果我从“call xml_parse”语句中去掉“pcdata_chunk_handler=pcdata_chunk”参数，这个程序就可以工作，但当然，输出中缺少描述和价格数据。