The using clause allows ESL to reference fields whose data is stored in non-ESL formats. The using clause specifies how ESL is to convert the data to and from the ESL type specified for the field. The ESL type defines the set of operations that can be performed on the field within ESL; for example:

 

structure MyStruct is

integer MyCShort using integer size 2

end structure

 

In this example, the first mention of integer before the field name MyCShort is the ESL type. The second mention, integer size 2, is the external format.

 

Two conversion methods are supported for fields stored in external formats. Depending on the storage format of the field, you specify one of the following:

 

A default conversion, if the external format of the field is one that ESL supports.

 

The name of your own external conversion routine that resides in a DLL, if the external format of the field is not supported by ESL.