Fix transposed weights in get_weight (#40)

Solves #39

Author: gdalle

src/abstractsimpleweightedgraph.jl

@@ -31,7 +31,7 @@ weighttype(::AbstractSimpleWeightedGraph{T,U}) where {T} where {U} = U
 
 Retrieve the weight of edge `(u, v)`.
 """
-get_weight(g::AbstractSimpleWeightedGraph, u::Integer, v::Integer) = weights(g)[v, u]
+get_weight(g::AbstractSimpleWeightedGraph, u::Integer, v::Integer) = weights(g)[u, v]
 
 ## Vertices
 

src/simpleweighteddigraph.jl

@@ -221,7 +221,7 @@ Base.:(==)(g::SimpleWeightedDiGraph, h::SimpleWeightedDiGraph) = g.weights == h.
 Graphs.is_directed(::Type{<:SimpleWeightedDiGraph}) = true
 
 """
-    g[e, :weight]
+    g[e, Val(:weight)]
 
 Return the weight of edge `e`.
 """
@@ -230,7 +230,7 @@ function Base.getindex(g::SimpleWeightedDiGraph, e::AbstractEdge, ::Val{:weight}
 end
 
 """
-    g[i, j, :weight]
+    g[i, j, Val(:weight)]
 
 Return the weight of edge `(i, j)`.
 """

test/simpleweightedgraph.jl

@@ -292,10 +292,13 @@ using SimpleWeightedGraphs
             add_edge!(g, 1, 2, 5.0)
 
             @test g[1, 2, Val{:weight}()] ≈ 5
+            @test get_weight(g, 1, 2) ≈ 5
             if is_directed(G)
                 @test g[2, 1, Val{:weight}()] ≈ 0
+                @test get_weight(g, 2, 1) ≈ 0
             else
                 @test g[2, 1, Val{:weight}()] ≈ 5
+                @test get_weight(g, 2, 1) ≈ 5
             end
             m = adjacency_matrix(g)
             @test g[2, 1, Val{:weight}()] ≈ g.weights[1, 2]