Calls (*mapfn)
once for each field in the specified group in the
attribute section of the given version. The call format is:
(*mapfn)(extra,tag,count,length);
where the arguments have the following declarations and contents:
is passed in to the LIBLINCKS function as an extra application program parameter. It is not used within LIBLINCKS, and is intended as a pointer to a call block for application program arguments to the map function.
points to the tag text as a null-terminated string placed in the internal field tag buffer.
contains the sequence number of the current field. The first field has number one (1), the second has number two (2), and so on. This enumeration is done every time GAN_GETATTRNAMES is called.
contains the number of fields in the given group in the attribute section. This number stays the same over all calls to the map function.
The map function is first called with a NULL `tag', and a zero `count'. This call is intended for initialisation. The mapping continues until the map function returns non zero, or there are no more fields.
See section 10 for an example of using a mapfn.
Function returns: