Varying length subfield contains blanks instead of length 0 ?

I'm having trouble understanding why a subfield of a data structure does not have the length designation (it crashes when I test with "when %len(datastructure(x).subfield) = 0;" ).
I get the RNX0115 Length of varying length variable is out of range. It clearly is out of range, because the value of the subfield is set to all blanks, and the length bytes show x'4040'.

My question is why the subfield is initiated to all blanks, including the length bytes, instead of to all x'00', like any other respectable varying length field should have?

Examining in SEP debug showing hex, I could see that the subfields with non-blank values did have proper length bytes, but they did have x'40' on all bytes that were beyond that length -- not x'00'.

I see in the archives that there was a lengthy discussion in Feb 2013 about how a varying length subfield operates somewhat differently, but no mention of this particular nuance.

Was not able to find anything in the docs about why a subfield defined as varying would get loaded with blanks.

Looks like testing for an "empty" varying subfield will need to be "if datastucture(x).subfield = *blanks" instead of testing its length. Let me know if there's a better alternative.


Michael Koester
Programmer/Analyst

DataEast