[Haskell-cafe] Physical equality

[José Romildo Malaquias]

Is there in Haskell a non monadic function of type a -> a -> Bool which
test for physical equality of two values? It would return True if only
if both values are the same object in memory.

For instance:

  value1 = "good"
  value2 = "good"

  eq value1 value2 => False

  value1 = "good"
  value2 = value1

  eq value1 value2 => True

Romildo