ErgoScript Design patterns

[anon_real]

To make sure some assets are distributed properly among many addresses (useful for airdrops for example):

  val properSending = {
    val imp = OUTPUTS.slice(1, OUTPUTS.size - 1)
    val appended = imp.fold(OUTPUTS(0).propositionBytes, {(x:Coll[Byte], b:Box) => {
      x ++ b.propositionBytes
    }})
    blake2b256(appended) == $outHash
  }

It both makes sure of proper outputs and preserves proper order. The same can be done for value.