private fun doReplace(replace: Command.Replace): CommandResult {
        val elementPath = currentPath.plus(replace.path)
        val toReplace = elementPath.getElement(rootElement)
        if (toReplace != null) {
            val parent = ElementPath(elementPath.segments.dropLast(1)).getElement(rootElement)
            when (parent) {
                is MutableElement.ArrayElement -> {
                    val index = replace.path.segments.last().substring(1,2).toInt()
                    parent.items[index] = replace.newElement.invoke()
                    return CommandResult.Success
                }
                is MutableElement.ObjectElement -> {
                    val index = replace.path.segments.last()
                    parent.items[index] = replace.newElement.invoke()
                    return CommandResult.Success
                }
            }
        }
        return findInvalidPath(replace.path)
    }