HL7 classes?

[ericksoda]

I have an application that reads an HL7 file, pulls the data from it, and then writes the data to another file, usually another HL7 file. This is like a very basic interface engine.

I would like to design some classes, but am unclear how they should be designed. Would these be the right approach?
1. File class
Methods
Get next record
Properties
End of file
Empty file
Multiple messages
2. Message class
Properties
MSH Segment
EVN Segment

This is where I get fuzzy. How do I deal with the elements in each segment? Do I make classes for MSH Segment with its properies being the various elements?

Thanks for any help!

David