bidirected-adjacency-array 1.1.1

Represent a bidirected graph via an adjacency array.
Documentation 
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use std::{
    fmt::{Debug, Display},
    hash::Hash,
};

use num_traits::{Bounded, PrimInt};
use optional_numeric_index::implement_generic_index;

pub trait GraphIndexInteger:
    PrimInt + Bounded + Hash + Debug + Display + From<u8> + TryFrom<usize> + TryInto<usize>
{
}

impl<T: PrimInt + Bounded + Hash + Debug + Display + From<u8> + TryFrom<usize> + TryInto<usize>>
    GraphIndexInteger for T
{
}

implement_generic_index!(pub NodeIndex, pub OptionalNodeIndex);
implement_generic_index!(pub EdgeIndex, pub OptionalEdgeIndex);

implement_generic_index!(pub DirectedNodeIndex, pub OptionalDirectedNodeIndex);
implement_generic_index!(pub DirectedEdgeIndex, pub OptionalDirectedEdgeIndex);

impl<IndexType: GraphIndexInteger> NodeIndex<IndexType> {
    pub fn into_directed(self, forward: bool) -> DirectedNodeIndex<IndexType> {
        DirectedNodeIndex::from_bidirected(self, forward)
    }

    pub fn into_directed_forward(self) -> DirectedNodeIndex<IndexType> {
        self.into_directed(true)
    }

    pub fn into_directed_reverse(self) -> DirectedNodeIndex<IndexType> {
        self.into_directed(false)
    }
}

impl<IndexType: GraphIndexInteger> EdgeIndex<IndexType> {
    pub(crate) fn increment(&mut self) {
        *self = Self::new(self.0 + 1u8.into());
    }

    pub(crate) fn sub(self, other: EdgeIndex<IndexType>) -> Self {
        Self::new(self.0 - other.0)
    }
}

impl<IndexType: GraphIndexInteger> DirectedNodeIndex<IndexType> {
    pub fn from_bidirected(bidirected: NodeIndex<IndexType>, forward: bool) -> Self {
        let base = bidirected.0 * 2u8.into();
        if forward {
            DirectedNodeIndex(base)
        } else {
            DirectedNodeIndex(base + 1u8.into())
        }
    }

    pub fn into_bidirected(self) -> NodeIndex<IndexType> {
        NodeIndex(self.0 / 2u8.into())
    }

    pub fn invert(self) -> Self {
        DirectedNodeIndex(self.0 ^ 1u8.into())
    }

    pub fn is_forward(self) -> bool {
        (self.0 & 1u8.into()) == 0u8.into()
    }

    pub fn is_reverse(self) -> bool {
        !self.is_forward()
    }

    pub(crate) fn add(self, other: DirectedNodeIndex<IndexType>) -> DirectedNodeIndex<IndexType> {
        Self::new(self.0 + other.0)
    }

    /// Changes the bidirected node index without affecting the direction.
    pub fn with_bidirected_node_index(self, bidirected: NodeIndex<IndexType>) -> Self {
        Self::from_bidirected(bidirected, self.is_forward())
    }
}

impl<IndexType: GraphIndexInteger> DirectedEdgeIndex<IndexType> {
    pub(crate) fn zero() -> Self {
        Self::new(0u8.into())
    }

    pub(crate) fn increment(&mut self) {
        *self = Self::new(self.0 + 1u8.into());
    }

    pub(crate) fn decrement(&mut self) {
        *self = Self::new(self.0 - 1u8.into());
    }

    pub(crate) fn add(self, other: DirectedEdgeIndex<IndexType>) -> DirectedEdgeIndex<IndexType> {
        Self::new(self.0 + other.0)
    }

    pub(crate) fn sub(self, other: DirectedEdgeIndex<IndexType>) -> DirectedEdgeIndex<IndexType> {
        Self::new(self.0 - other.0)
    }
}