Function opcodePick

txscript/opcode.go:1333–1340

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

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

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

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

// 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.