I’m just discovering make_ref/0 and I’m wondering how to print them as a string… I have poked through the source code, but I don’t see any way to see inside the reference values.

Yeah, sorry, it should be :erlang.ref_to_list/1.

This worked for me: iex(5)> "#{inspect make_ref}" "#Reference<0.4290490855.1120927745.192473>" Never used references before but it seems it can be printed just fine. Or are you looking for a certain property?

Don’t expect to. A reference is just a marker to a “place and time”. They’re usually otherwise empty values that are “guaranteed” to be unique. Now, sometimes they are coopted by the vm to refer to “something” but by and large they aren’t references like references in the JVM. For example, let m…

demo, you can see the return address PID and a reference packaged with the call content quite clearly: iex(1)> self() #PID<0.105.0> iex(2)> pid = spawn(fn -> receive do any -> any end |> IO.inspect end) # trap the next message and print it #PID<0.108.0> iex(3)> GenServer.call(pid, :foo) # pretend t…

make_ref() |> :erlang.ref_to_list() |> List.to_string()

[image] hauleth: make_ref() |> :erlang.reference_to_string() |> List.to_string() ** (UndefinedFunctionError) function :erlang.reference_to_string/1 is undefined or private. Did you mean one of: * ref_to_list/1 :erlang.reference_to_string(#Reference<0.1918863630.4161011720.226556>)…

I should clarify the use here: I’m working on a (mostly academic) exercise that seeks to run code in multiple modules, sometimes with different runtime values given to the same module, so I want a unique identifier for each “instance” (if you’ll forgive the OO speak). A reference seemed the most ap…

Remember that references are meant to be unique only within single cluster, there is no guarantee for global uniqueness of the reference, in contrast to UUID.

Uuids also have a slightly weak guarantee. Collisions are possible. However, you’ll probably be ok.

Much stronger than make_ref/0 (64 bits vs 122 bits, which with birthday collision will provide 1010 difference factor in possible collisions). And generating UUID can be done also outside of the BEAM, which is clearly a win for me.

True, however the fact that most libraries compare them as strings rubs me off the wrong way. I’d feel much better if UUIDs were actually treated as byte arrays and compared as such (or in Erlang/Elixir’s case, fixed-size tuples of integers). IMO that leaves some untapped performance potential on th…

Elixir Programming Language Forum

Printing references as strings?

Questions & Help Questions

dimitarvp February 24, 2023, 9:53pm 20

True, I was kind of referring to the API contract.