From 0feb5396d9aa0142cd4292f138ccf17d83f8339b Mon Sep 17 00:00:00 2001
From: Matt Fishman <mtfishman@users.noreply.github.com>
Date: Fri, 26 Apr 2024 14:12:15 -0400
Subject: [PATCH] `NamedGraph` conversion (#76)

---
 src/namedgraph.jl       | 21 +++++++++++++++++++++
 test/test_namedgraph.jl | 16 ++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/src/namedgraph.jl b/src/namedgraph.jl
index b58a273..d076d46 100644
--- a/src/namedgraph.jl
+++ b/src/namedgraph.jl
@@ -169,6 +169,27 @@ end
 
 GenericNamedGraph() = GenericNamedGraph(Any[])
 
+function GenericNamedGraph(graph::GenericNamedGraph)
+  return GenericNamedGraph{vertextype(graph),position_graph_type(graph_type)}(graph)
+end
+function GenericNamedGraph{V}(graph::GenericNamedGraph) where {V}
+  return GenericNamedGraph{V,position_graph_type(graph_type)}(graph)
+end
+function GenericNamedGraph{<:Any,G}(
+  graph::GenericNamedGraph
+) where {G<:AbstractSimpleGraph{Int}}
+  return GenericNamedGraph{vertextype(graph),G}(graph)
+end
+function GenericNamedGraph{V,G}(
+  graph::GenericNamedGraph
+) where {V,G<:AbstractSimpleGraph{Int}}
+  return GenericNamedGraph{V,G}(copy(position_graph(graph)), copy(vertices(graph)))
+end
+
+function Base.convert(graph_type::Type{<:GenericNamedGraph}, graph::GenericNamedGraph)
+  return graph_type(graph)
+end
+
 # TODO: implement as:
 # graph = set_position_graph(graph, copy(position_graph(graph)))
 # graph = set_vertices(graph, copy(vertices(graph)))
diff --git a/test/test_namedgraph.jl b/test/test_namedgraph.jl
index 02fe7bd..2d9e6c0 100644
--- a/test/test_namedgraph.jl
+++ b/test/test_namedgraph.jl
@@ -149,6 +149,22 @@ end
     rem_vertex!(g, "E")
     @test !has_vertex(g, "E")
 
+    g = NamedGraph(grid((4,)), ["A", "B", "C", "D"])
+    for gc in (NamedGraph(g), convert(NamedGraph, g))
+      @test gc == g
+      @test gc isa NamedGraph{String}
+      @test vertextype(gc) === vertextype(g)
+      @test issetequal(vertices(gc), vertices(g))
+      @test issetequal(edges(gc), edges(g))
+    end
+    for gc in (NamedGraph{Any}(g), convert(NamedGraph{Any}, g))
+      @test gc == g
+      @test gc isa NamedGraph{Any}
+      @test vertextype(gc) === Any
+      @test issetequal(vertices(gc), vertices(g))
+      @test issetequal(edges(gc), edges(g))
+    end
+
     io = IOBuffer()
     show(io, "text/plain", g)
     @test String(take!(io)) isa String