ordered_members vs. members and their interactions

members.rb

# How do ordered_members and members behave and interact

# Setup
col1 = Hydra::Works::Collection.new(id: 'c1')
wrk1 = Hydra::Works::Work.new(id: 'w1')
wrk2 = Hydra::Works::Work.new(id: 'w2')
wrk3 = Hydra::Works::Work.new(id: 'w3')
wrk4 = Hydra::Works::Work.new(id: 'w4')

# 1. adding to members does NOT add to ordered members
col1.members << wrk1
col1.members.size                   # => 1 -- w1
Array(col1.ordered_members).size    # => 0

# 2. adding to ordered_members does add to members
col1.ordered_members << wrk4
col1.members.size                   # => 2 -- w1, w4  (order unimportant)
Array(col1.ordered_members).size    # => 1 -- w4

# 3. adding the same object again to ordered_members does NOT add to members
col1.ordered_members << wrk4
col1.members.size                   # => 2 -- w1, w4  (order unimportant)
Array(col1.ordered_members).size    # => 2 -- w4, w4  (precise order)

# add a few more to work with for deletes
col1.ordered_members << wrk2
col1.ordered_members << wrk3
col1.members.size                   # => 4 -- w1, w2, w3, w4  (order unimportant)
Array(col1.ordered_members).size    # => 4 -- w4, w4, w2, w3  (precise order)

# 3. deleting from members does NOT effect ordered_members
col1.members.delete(wrk3)
col1.members.size                   # => 3 -- w1, w2, w4  (order unimportant)
Array(col1.ordered_members).size    # => 4 -- w4, w4, w2, w3  (precise order)

# 4. deleting from ordered_members does NOT effect members
col1.ordered_members.delete_at(2)
col1.members.size                   # => 3 -- w1, w2, w4  (order unimportant)
Array(col1.ordered_members).size    # => 2 -- w4, w4, w3  (precise order)

The set of triples that are being generated in Fedora do not appear to match the concept of Resource Map described in the ORE spec. If you see this differently, can you explain how you understand this implementation to match ORE Resource Maps?

@barmintor duraspace/pcdm#10 WIP

What is a use case for a partial_ordered list?