Add From and FromGraph implementations for Graph and AppendGraph

src/models/append_graph.rs

@@ -3,7 +3,8 @@
 use std::num::NonZeroUsize;
 
 use crate::maps::ElementMap;
-use crate::traits::{GraphTopology, GraphTopologyAddition, Incidence, IncidenceCursor};
+use crate::models;
+use crate::traits::{FromGraph, GraphTopology, GraphTopologyAddition, Incidence, IncidenceCursor};
 
 /// An opaque handle identifying a vertex in an [`AppendGraph`].
 ///
@@ -259,14 +260,38 @@ impl GraphTopologyAddition for AppendGraph {
     }
 }
 
+impl<H: GraphTopology> From<&H> for AppendGraph {
+    fn from(source: &H) -> Self {
+        models::build_from_topology::<Self, _>(source, Vertex(usize::MAX), |_, _| {}).0
+    }
+}
+
+impl FromGraph for AppendGraph {
+    fn from_graph<H: GraphTopology>(
+        source: &H,
+    ) -> (
+        Self,
+        ElementMap<H::Vertex, Vertex>,
+        ElementMap<H::Edge, Edge>,
+    ) {
+        let mut edge_map = source.edge_map(Edge(NonZeroUsize::MAX));
+        let (result, vertex_map) =
+            models::build_from_topology(source, Vertex(usize::MAX), |e, new_e| edge_map[e] = new_e);
+        (result, vertex_map, edge_map)
+    }
+}
+
 #[cfg(test)]
 mod trait_tests {
     use super::AppendGraph;
+    use crate::models::Graph;
 
     crate::graph_topology_tests!(AppendGraph);
     crate::graph_topology_addition_tests!(AppendGraph);
     crate::graph_topology_clone_tests!(AppendGraph);
     crate::graph_topology_addition_clone_tests!(AppendGraph);
+    crate::graph_topology_from_graph_tests!(AppendGraph, Graph);
+    crate::graph_topology_addition_from_graph_tests!(AppendGraph, Graph);
 }
 
 #[cfg(test)]

src/models/graph.rs

@@ -4,8 +4,10 @@ use std::num::NonZeroUsize;
 use typed_generational_arena::{Arena, Index};
 
 use crate::maps::ElementMap;
+use crate::models;
 use crate::traits::{
-    GraphTopology, GraphTopologyAddition, GraphTopologyDeletion, Incidence, IncidenceCursor,
+    FromGraph, GraphTopology, GraphTopologyAddition, GraphTopologyDeletion, Incidence,
+    IncidenceCursor,
 };
 
 /// An opaque handle identifying a vertex in a [`Graph`].
@@ -398,9 +400,38 @@ impl GraphTopologyDeletion for Graph {
     }
 }
 
+impl<H: GraphTopology> From<&H> for Graph {
+    fn from(source: &H) -> Self {
+        models::build_from_topology::<Self, _>(
+            source,
+            Vertex::new(usize::MAX, usize::MAX),
+            |_, _| {},
+        )
+        .0
+    }
+}
+
+impl FromGraph for Graph {
+    fn from_graph<H: GraphTopology>(
+        source: &H,
+    ) -> (
+        Self,
+        ElementMap<H::Vertex, Vertex>,
+        ElementMap<H::Edge, Edge>,
+    ) {
+        let mut edge_map = source.edge_map(Edge::new(usize::MAX, usize::MAX));
+        let (result, vertex_map) =
+            models::build_from_topology(source, Vertex::new(usize::MAX, usize::MAX), |e, new_e| {
+                edge_map[e] = new_e
+            });
+        (result, vertex_map, edge_map)
+    }
+}
+
 #[cfg(test)]
 mod trait_tests {
     use super::Graph;
+    use crate::models::AppendGraph;
 
     crate::graph_topology_tests!(Graph);
     crate::graph_topology_addition_tests!(Graph);
@@ -408,6 +439,8 @@ mod trait_tests {
     crate::graph_topology_addition_deletion_tests!(Graph);
     crate::graph_topology_clone_tests!(Graph);
     crate::graph_topology_addition_clone_tests!(Graph);
+    crate::graph_topology_from_graph_tests!(Graph, AppendGraph);
+    crate::graph_topology_addition_from_graph_tests!(Graph, AppendGraph);
 }
 
 #[cfg(test)]