From d55b1369e030ae8e1d07a061737cfc0b82cfdba0 Mon Sep 17 00:00:00 2001
From: CarloLucibello <carlo.lucibello@gmail.com>
Date: Tue, 12 Apr 2016 09:19:34 +0200
Subject: [PATCH] add DummyEdgeMap and make it default

---
 src/LightGraphs.jl           | 4 ++--
 src/traversals/bfs.jl        | 2 +-
 src/traversals/dfs.jl        | 2 +-
 src/traversals/graphvisit.jl | 9 +++++++++
 4 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/LightGraphs.jl b/src/LightGraphs.jl
index 805ed8839..3e8d5c2cd 100644
--- a/src/LightGraphs.jl
+++ b/src/LightGraphs.jl
@@ -23,9 +23,9 @@ catch
 end
 
 import Base: write, ==, <, *, isless, issubset, complement, union, intersect,
-            reverse, reverse!, blkdiag, getindex, show, print, copy, in,
+            reverse, reverse!, blkdiag, getindex, setindex!, show, print, copy, in,
             sum, size, sparse, eltype, length, ndims, issym, transpose,
-            ctranspose, join, start, next, done, eltype
+            ctranspose, join, start, next, done, eltype, get
 
 
 # core
diff --git a/src/traversals/bfs.jl b/src/traversals/bfs.jl
index c006a0191..9baa06faf 100644
--- a/src/traversals/bfs.jl
+++ b/src/traversals/bfs.jl
@@ -49,7 +49,7 @@ function traverse_graph!(
     source,
     visitor::SimpleGraphVisitor;
     vertexcolormap = zeros(Int, nv(graph)),
-    edgecolormap = Dict{Edge, Int}(),
+    edgecolormap = DummyEdgeMap(),
     queue = Vector{Int}())
 
     for s in source
diff --git a/src/traversals/dfs.jl b/src/traversals/dfs.jl
index 93f45af4e..0226b22ee 100644
--- a/src/traversals/dfs.jl
+++ b/src/traversals/dfs.jl
@@ -59,7 +59,7 @@ function traverse_graph!(
     s::Int,
     visitor::SimpleGraphVisitor;
     vertexcolormap = zeros(Int, nv(graph)),
-    edgecolormap = Dict{Edge, Int}())
+    edgecolormap = DummyEdgeMap())
 
     vertexcolormap[s] = 1
     discover_vertex!(visitor, s) || return
diff --git a/src/traversals/graphvisit.jl b/src/traversals/graphvisit.jl
index 36bc16e1e..9d9efe24e 100644
--- a/src/traversals/graphvisit.jl
+++ b/src/traversals/graphvisit.jl
@@ -28,6 +28,15 @@ end
 # This is the common base for BreadthFirst and DepthFirst
 abstract SimpleGraphVisitAlgorithm
 
+type DummyEdgeMap
+end
+
+getindex(d::DummyEdgeMap, e::Edge) = 0
+setindex!(d::DummyEdgeMap, x, e::Edge) = x
+get(d::DummyEdgeMap, e::Edge, x) = x
+
+
+
 
 ###########################################################
 #