Merge pull request #9 from yuyichao/0.6

Fix 0.6 abstract type declaration depwarn

REQUIRE

@@ -1,2 +1,2 @@
 julia 0.5
-Compat 0.9.5
+Compat 0.17.0

src/AbstractTrees.jl

@@ -10,7 +10,7 @@ import Base: getindex, setindex!, start, next, done, nextind, print, show,
 using Base: SizeUnknown
 using Compat
 
-abstract AbstractShadowTree
+@compat abstract type AbstractShadowTree end
 
 include("traits.jl")
 include("implicitstacks.jl")
@@ -267,7 +267,7 @@ eltype{I}(::Type{IndEnumerate{I}}) = Tuple{Any, eltype(I)}
 
 # Tree Iterators
 
-abstract TreeIterator{T}
+@compat abstract type TreeIterator{T} end
 
 """
 Iterator to visit the leaves of a tree, e.g. for the tree

src/implicitstacks.jl

@@ -1,4 +1,4 @@
-abstract ImplicitStack
+@compat abstract type ImplicitStack end
 immutable ImplicitIndexStack{S} <: ImplicitStack
     stack::Vector{S}
 end
@@ -18,7 +18,7 @@ Base.isempty(s::ImplicitIndexStack) = isempty(s.stack)
 getnode(tree, ns::ImplicitIndexStack) = isempty(ns.stack) ? tree[rootstate(tree)] :
     (@assert isa(treekind(tree), IndexedTree); tree[ns.stack[end]])
 function getnode(tree, stack::ImplicitNodeStack)
-    isempty(stack.node_stack) ? 
+    isempty(stack.node_stack) ?
     (isempty(stack.idx_stack) ? tree : children(tree)[stack.idx_stack.stack[end]]) :
     children(stack.node_stack[end])[stack.idx_stack.stack[end]]
 end

src/traits.jl

@@ -1,4 +1,4 @@
-abstract ParentLinks
+@compat abstract type ParentLinks end
 
 """
   Indicates that this tree stores parent links explicitly. The implementation
@@ -11,7 +11,7 @@ immutable ImplicitParents <: ParentLinks; end
 parentlinks(::Type) = ImplicitParents()
 parentlinks(tree) = parentlinks(typeof(tree))
 
-abstract SiblingLinks
+@compat abstract type SiblingLinks end
 
 """
   Indicates that this tree stores sibling links explicitly, or can compute them
@@ -27,7 +27,7 @@ siblinglinks(::Type) = ImplicitSiblings()
 siblinglinks(tree) = parentlinks(typeof(tree))
 
 
-abstract TreeKind
+@compat abstract type TreeKind end
 immutable RegularTree <: TreeKind; end
 immutable IndexedTree <: TreeKind; end
 
@@ -38,7 +38,7 @@ children(tree, node, ::IndexedTree) = (tree[y] for y in childindices(tree, node)
 children(tree, node) = children(tree, node, treekind(tree))
 
 function rootstate()
-end  
+end
 
 childindices(tree, node) =
   tree == node ? childindices(tree, rootstate(tree)) :