Stream: IG creation
Topic: ext-1
Richard Townley-O'Neill (Jun 22 2021 at 06:48):
The definition of extension includes ext-1 Rule Must have either extensions or value[x], not both extension.exists() != value.exists()
At the same time many core extensions explicitly make extension.extension 0..0 when extension.value is of interest (e.g. Anonymized). Others make extension.value 0..0 when extension.extension is of interest (e.g. oauth-uris)
Why explicitly set cardinalities to 0..0 when the invariant already checks this?
Why not just use the invariant?
Grahame Grieve (Jun 22 2021 at 07:25):
it's useful to provide direct guidance, but as you point out, it's not necessary
Lloyd McKenzie (Jun 25 2021 at 03:00):
Mainly about making it immediately visually obvious to the reader. (Few think to look at - or sometimes even understand the invariants, especially the 'general' ones.)
Last updated: Apr 12 2022 at 19:14 UTC
