Spawn long running process (tail-called) sleeps without hanging IEX?

Questions / Help
1

In Elixir how can you spawn a long running process (tail-called) that sleeps without hanging IEX?

Example:

def longrunner() do
    IO.puts "do something..."
    :timer.sleep(10000)       // :timer.sleep blocks IEX repl
    longrunner()
end

myrunner = spawn(longrunner)
2

the problem is how you are calling it.

spawn(longrunner) tries to run and evaluate the longrunner function (due to optional parentheses) before it calls spawn . That is why it is hanging.

Try:
myrunner = spawn(fn() -> longrunner() end)

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3

longrunner is not a variable/binding, it is a function, thus it is actually doing this:

myrunner = spawn(longrunner())

Of which would never return so spawn never even gets called. You probably want to pass the function rather than call the function:

myrunner = spawn(&longrunner/0)
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