begin wrapping iterator

Author: rayegun

src/SuiteSparseGraphBLAS.jl

@@ -90,6 +90,7 @@ include("misc.jl")
 include("asjulia.jl")
 # include("spmgb/sparsemat.jl")
 include("mmread.jl")
+include("iterator.jl")
 
 export SparseArrayCompat
 export LibGraphBLAS

src/iterator.jl

@@ -0,0 +1,18 @@
+struct GBIterator{O}
+    p::Ref{LibGraphBLAS.GxB_Iterator}
+end
+gbpointer(I::GBIterator) = I.p[]
+
+function GBIterator(bycol=true) # this should be removed eventually. We always want an attached one.
+    i = Ref{LibGraphBLAS.GxB_Iterator}()
+    @wraperror LibGraphBLAS.GxB_Iterator_new(i)
+    return GBIterator{}(finalizer(iter) do ref
+        @wraperror LibGraphBLAS.GxB_Iterator_free(ref)
+    end)
+end
+
+function attach(I::GBIterator, A::AbstractGBArray; desc = nothing, itercolumns)
+    desc = _handledescriptor(desc)
+    @wraperror LibGraphBLAS.GxB_Iterator_attach(gbpointer(I), gbpointer(A), desc)
+end
+