Function opcodeRoll

txscript/opcode.go:1348–1355

opcodeRoll treats the top item on the data stack as an integer and moves the item on the stack that number of items back to the top. Stack transformation: [xn ... x2 x1 x0 n] -> [... x2 x1 x0 xn] Example with n=1: [x2 x1 x0 1] -> [x2 x0 x1] Example with n=2: [x2 x1 x0 2] -> [x1 x0 x2]

(op *opcode, data []byte, vm *Engine)

// Example with n=1: [x2 x1 x0 1] -> [x2 x0 x1]
// Example with n=2: [x2 x1 x0 2] -> [x1 x0 x2]
func opcodeRoll(op *opcode, data []byte, vm *Engine) error {
	val, err := vm.dstack.PopInt()
	if err != nil {
		return err
	}

	return vm.dstack.RollN(val.Int32())
}

// opcodeRot rotates the top 3 items on the data stack to the left.
//