use std::error::Error;
use std::fmt;
#[derive(Debug, Eq, PartialEq)]
pub enum NodeIdError {
InvalidNodeIdForTree,
NodeIdNoLongerValid,
}
impl NodeIdError {
fn to_string(&self) -> &str {
match *self {
NodeIdError::InvalidNodeIdForTree => "The given NodeId belongs to a different Tree.",
NodeIdError::NodeIdNoLongerValid => {
"The given NodeId is no longer valid. The Node in question has been \
removed."
}
}
}
}
impl fmt::Display for NodeIdError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "NodeIdError: {}", self.to_string())
}
}
impl Error for NodeIdError {
fn description(&self) -> &str {
self.to_string()
}
}