You may also take advantage of the predefined fun function to obtain a reference to a closure, as in:

import golotest.Closures

local function local_fun = |x| -> x + 1

function call_local_fun = {

  # local_fun, with a parameter
  var f = fun("local_fun", golotest.Closures.module, 1)

  # ...or just like this if there is only 1 local_fun definition
  f = fun("local_fun", golotest.Closures.module)

  return f(1)
}

Last but not least, we have an even shorter notation if function are not overridden:

import golotest.Closures

local function local_fun = |x| -> x + 1

function call_local_fun = {

  # In the current module
  var f = ^local_fun

  # ...or with a full module name
  f = ^golotest.Closures::local_fun

  return f(1)
}