[This message was posted by Guangbin Xu of SSE <[email protected]> to the "FAST Protocol" discussion forum at http://fixprotocol.org/discuss/46. You can reply to it on-line at http://fixprotocol.org/discuss/read/c840aadb - PLEASE DO NOT REPLY BY MAIL.]
According to my implementation, the bitGroup needs no presence attribute. Because unlike those of a group, the elements are grouped just for the purpose of space saving and they are unnecessarily semantically relevant. However, you can still implement the presence of the bitGroup. That will be compatible for either situation. BTW, the bitGroup should have a PMAP if it is a segment (although this is a different question). To judge whether a group/bitGroup is a segment or not, the slot-needing situation of all its sub-elements should be scanned. If any of them need a slot, the bitGroup is a segment, otherwise not a one. FYI Guangbin Xu Shanghai Stock Exchange > Hi, > > I am attempting to add preliminary support for bit groups and noticed that > within the latest version of the FAST 1.2 extension proposals, it is not > specified whether or not a bit group field supports a presence attribute. > Are presence attributes supported for bit groups? > > Also, the bit group proposal implies that the bit group field does support > (some) field operators as a copy operator is present within the syntax > examples. > > If field operators are supported as well as a presence attribute, it seems > like a NULL representation is required for bit groups. How should NULL be > represented? Also, what is the interaction of the bit group's presence > attribute and field operator, if any, with fields within the bit group? > > Thanks, > > Donnell Bell [You can unsubscribe from this discussion group by sending a message to mailto:[email protected]] -- You received this message because you are subscribed to the Google Groups "Financial Information eXchange" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/fix-protocol?hl=en.
