Merge pull request #23 from JuliaGraphs/sbromberger/newshow

change show() for empty graphs (ref https://github.com/JuliaGraphs/Me…

Author: sbromberger

src/MetaGraphs.jl

@@ -49,11 +49,7 @@ abstract type AbstractMetaGraph{T} <: AbstractGraph{T} end
 
 function show(io::IO, g::AbstractMetaGraph)
     dir = is_directed(g) ? "directed" : "undirected"
-    if nv(g) == 0
-        print(io, "empty $dir $(eltype(g)) metagraph with $(weighttype(g)) weights defined by :$(g.weightfield) (default weight $(g.defaultweight))")
-    else
-        print(io, "{$(nv(g)), $(ne(g))} $dir $(eltype(g)) metagraph with $(weighttype(g)) weights defined by :$(g.weightfield) (default weight $(g.defaultweight))")
-    end
+    print(io, "{$(nv(g)), $(ne(g))} $dir $(eltype(g)) metagraph with $(weighttype(g)) weights defined by :$(g.weightfield) (default weight $(g.defaultweight))")
 end
 
 @inline fadj(g::AbstractMetaGraph, x...) = fadj(g.graph, x...)

test/metagraphs.jl

@@ -145,7 +145,7 @@ importall MetaGraphs
         mg = MetaGraph(g)
         T = eltype(mg)
         U = weighttype(mg)
-        @test sprint(show, mg) == "empty undirected $T metagraph with $U weights defined by :$(mg.weightfield) (default weight $(mg.defaultweight))"
+        @test sprint(show, mg) == "{0, 0} undirected $T metagraph with $U weights defined by :$(mg.weightfield) (default weight $(mg.defaultweight))"
         @test @inferred(add_vertices!(g, 5)) == 5
         @test sprint(show, mg) == "{5, 0} undirected $T metagraph with $U weights defined by :$(mg.weightfield) (default weight $(mg.defaultweight))"
     end
@@ -154,7 +154,7 @@ importall MetaGraphs
         mg = MetaDiGraph(g)
         T = eltype(mg)
         U = weighttype(mg)
-        @test sprint(show, mg) == "empty directed $T metagraph with $U weights defined by :$(mg.weightfield) (default weight $(mg.defaultweight))"
+        @test sprint(show, mg) == "{0, 0} directed $T metagraph with $U weights defined by :$(mg.weightfield) (default weight $(mg.defaultweight))"
         @test @inferred(add_vertices!(mg, 5)) == 5
         @test sprint(show, mg) == "{5, 0} directed $T metagraph with $U weights defined by :$(mg.weightfield) (default weight $(mg.defaultweight))"
     end