-- Fun.
-- (C) Dmitry Boulytchev, JetBrains Research, St. Petersburg State University, 2020
--
-- This unit provides some convenient function-manipulation stuff.

import Ref;

public fun id (x) {
  x
}

public infixl $ after := (f, x) {
  f (x)
}

public infix # after * (f, g) {
  fun (x) {
    f (g (x))
  }
}

public fun fix (f) {
  local knot = ref ({});
  
  knot ::= fun (x) {f (deref (knot)) (x)};  

  deref (knot)
}