Hash function (djb2)

/// @brief Implementation of djb2 in plain Igor Pro
///
/// The implementation here does support embedded nulls, see DisplayHelpTopic "Embedded Nulls in Literal Strings".
///
/// See also https://github.com/dim13/djb2/blob/master/docs/hash.md#djb2.
threadsafe Function [uint64 h] HM_DJBHash(string str)
  uint64 d
  h = 5381
  WAVE/U/B wv = StringToUnsignedByteWave(str)
  for(d : wv)
    h = h * 33 + d
  endfor
  return [h]
End

This is also a nice example for when and how to use the integer types.