use std::{
fmt::{Debug, Display},
hash::Hash,
};
pub type NodesIterator<'a, T> = Box<dyn Iterator<Item = T> + 'a>;
pub type LabelIterator<'a, T> = Box<dyn Iterator<Item = T> + 'a>;
pub type PropertyIterator<'a, K, V> = Box<dyn Iterator<Item = (K, V)> + 'a>;
pub trait Graph {
type NodeId: Debug + Hash + Eq + ?Sized;
type NodeLabel: Display + ?Sized;
type RelationshipType: Display + ?Sized;
type PropertyKey: Display + ?Sized;
type PropertyValue: Display + ?Sized;
fn nodes(&self) -> NodesIterator<&Self::NodeId>;
fn node_labels(&self, node_id: &Self::NodeId) -> LabelIterator<&Self::NodeLabel>;
fn node_properties(
&self,
node_id: &Self::NodeId,
) -> PropertyIterator<&Self::PropertyKey, &Self::PropertyValue>;
fn outgoing_relationships<'a, 'b: 'a>(
&'a self,
node_id: &'b Self::NodeId,
) -> PropertyIterator<
(&'a Self::NodeId, &'a Self::RelationshipType),
PropertyIterator<&'a Self::PropertyKey, &'a Self::PropertyValue>,
>;
fn incoming_relationships<'a, 'b: 'a>(
&'a self,
node_id: &'b Self::NodeId,
) -> PropertyIterator<
(&'a Self::NodeId, &'a Self::RelationshipType),
PropertyIterator<&'a Self::PropertyKey, &'a Self::PropertyValue>,
>;
}