From 3cca2b102f36993f1461c058eaedcbf48dceaad6 Mon Sep 17 00:00:00 2001
From: Matt Fishman <mtfishman@users.noreply.github.com>
Date: Wed, 24 Apr 2024 00:27:11 -0400
Subject: [PATCH] Define `convert_vertextype` for `Simple[Di]Graph` (#72)

---
 Project.toml                                |  2 +-
 src/lib/GraphsExtensions/src/simplegraph.jl | 11 +++++++++++
 src/lib/GraphsExtensions/test/runtests.jl   | 10 ++++++++++
 src/namedgraph.jl                           |  8 ++++----
 4 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/Project.toml b/Project.toml
index 9614857..2b8a015 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "NamedGraphs"
 uuid = "678767b0-92e7-4007-89e4-4527a8725b19"
 authors = ["Matthew Fishman <mfishman@flatironinstitute.org> and contributors"]
-version = "0.5.0"
+version = "0.5.1"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
diff --git a/src/lib/GraphsExtensions/src/simplegraph.jl b/src/lib/GraphsExtensions/src/simplegraph.jl
index 3c0ecd4..af3fbf2 100644
--- a/src/lib/GraphsExtensions/src/simplegraph.jl
+++ b/src/lib/GraphsExtensions/src/simplegraph.jl
@@ -6,8 +6,19 @@ function graph_from_vertices(graph_type::Type{<:AbstractSimpleGraph}, vertices)
   return graph_type(length(vertices))
 end
 
+function convert_vertextype(vertextype::Type, graph::AbstractSimpleGraph)
+  return not_implemented()
+end
+
 using Graphs.SimpleGraphs: SimpleDiGraph, SimpleGraph
 
+function convert_vertextype(vertextype::Type, graph::SimpleGraph)
+  return SimpleGraph{vertextype}(graph)
+end
+function convert_vertextype(vertextype::Type, graph::SimpleDiGraph)
+  return SimpleDiGraph{vertextype}(graph)
+end
+
 directed_graph_type(G::Type{<:SimpleGraph}) = SimpleDiGraph{vertextype(G)}
 # TODO: Use traits to make this more general.
 undirected_graph_type(G::Type{<:SimpleGraph}) = G
diff --git a/src/lib/GraphsExtensions/test/runtests.jl b/src/lib/GraphsExtensions/test/runtests.jl
index c724dd7..36db807 100644
--- a/src/lib/GraphsExtensions/test/runtests.jl
+++ b/src/lib/GraphsExtensions/test/runtests.jl
@@ -45,6 +45,7 @@ using NamedGraphs.GraphsExtensions:
   all_edges,
   child_edges,
   child_vertices,
+  convert_vertextype,
   degrees,
   directed_graph,
   directed_graph_type,
@@ -97,6 +98,15 @@ using Test: @test, @test_broken, @test_throws, @testset
 # - random_bfs_tree
 
 @testset "NamedGraphs.GraphsExtensions" begin
+  # convert_vertextype
+  for g in (path_graph(4), path_digraph(4))
+    g_uint16 = convert_vertextype(UInt16, g)
+    @test g_uint16 == g
+    @test vertextype(g_uint16) == UInt16
+    @test issetequal(vertices(g_uint16), vertices(g))
+    @test issetequal(edges(g_uint16), edges(g))
+  end
+
   # is_self_loop
   @test is_self_loop(SimpleEdge(1, 1))
   @test !is_self_loop(SimpleEdge(1, 2))
diff --git a/src/namedgraph.jl b/src/namedgraph.jl
index c00cc5b..6c6e075 100644
--- a/src/namedgraph.jl
+++ b/src/namedgraph.jl
@@ -72,9 +72,9 @@ function GraphsExtensions.rename_vertices(f::Function, g::AbstractSimpleGraph)
   )
 end
 
-function GraphsExtensions.convert_vertextype(V::Type, graph::GenericNamedGraph)
+function GraphsExtensions.convert_vertextype(vertextype::Type, graph::GenericNamedGraph)
   return GenericNamedGraph(
-    parent_graph(graph), convert(Vector{V}, graph.parent_vertex_to_vertex)
+    parent_graph(graph), convert(Vector{vertextype}, graph.parent_vertex_to_vertex)
   )
 end
 
@@ -92,8 +92,8 @@ function to_vertices(vertices::Tuple{Vararg{Integer}})
   return vec(Tuple.(CartesianIndices(vertices)))
 end
 to_vertices(vertices::Integer) = to_vertices(Base.OneTo(vertices))
-function to_vertices(V::Type, vertices)
-  return convert(Vector{V}, to_vertices(vertices))
+function to_vertices(vertextype::Type, vertices)
+  return convert(Vector{vertextype}, to_vertices(vertices))
 end
 
 #