Loom.MVRegister
A causally consistent multi-value register.
A bit more causally rigorous than LWWRegister, MVRegister will replace observed values when they are set, but concurrent additions will co-occur, and a list will be returned for the value.
This is good if you have some reasonable way of figuring out how to resolve this further down your app keychain (including user resolution), but you can’t make it generic enough to work as a CRDT.
Summary
| join(mvregister, mvregister) | Joins 2 MVRegisters |
| new() | Returns a new MVRegister CRDT |
| set(reg, actor, value) | Sets a value, erasing any current values |
| value(mvregister) | Returns the natural value of the register. If there is nothing, it’s nil. If it’s one thing, it’s that value (this is the normal case). If it’s more than one thing, all values are returned in a list |
Functions
Specs:
Joins 2 MVRegisters
iex> alias Loom.MVRegister, as: Reg
iex> {a, _} = Reg.new |> Reg.set(:a, "test") |> Reg.set(:a, "test2")
iex> {b, _} = Reg.new |> Reg.set(:b, "take over")
iex> Reg.join(a, b) |> Reg.value
["test2", "take over"]Specs:
- new :: t
Returns a new MVRegister CRDT.
nil is a new CRDT’s identity value, and by default the system time in
microseconds is used as the clock value.
iex> Loom.MVRegister.new |> Loom.MVRegister.value
nilSpecs:
Sets a value, erasing any current values.
iex> alias Loom.MVRegister, as: Reg
iex> Reg.new
...> |> Reg.set(:a, "test")
...> |> Reg.set(:a, "test2")
...> |> Reg.value
"test2"Specs:
Returns the natural value of the register. If there is nothing, it’s nil. If it’s one thing, it’s that value (this is the normal case). If it’s more than one thing, all values are returned in a list.