fix multiscale iteration

Author: ChrisRackauckas

src/level_iterations.jl

@@ -5,10 +5,26 @@ struct LevelIterIdx{T}
 end
 LevelIterIdx(S::AbstractMultiScaleArray, n::Int) = LevelIterIdx(level_iter(S, n))
 
-Base.start(l::LevelIterIdx) = (start(l.iter), 1)
-function Base.next(l::LevelIterIdx, state)
+start(l::LevelIterIdx) = (start(l.iter), 1)
+function next(l::LevelIterIdx, state)
     val, new_state = next(l.iter, state[1])
     end_idx = state[2] + length(val) - 1
     ((val, state[2], end_idx), (new_state, end_idx + 1))
 end
-Base.done(l::LevelIterIdx, state) = done(l.iter, state[1])
+done(l::LevelIterIdx, state) = done(l.iter, state[1])
+
+function Base.iterate(l::LevelIterIdx)
+    x = iterate(l.iter)
+    x == nothing && return nothing
+    val, new_state = x
+    end_idx = 1 + length(val) - 1
+    ((val, 1, end_idx), (new_state, end_idx + 1))
+end
+
+function Base.iterate(l::LevelIterIdx,state)
+    x = iterate(l.iter,state[1])
+    x == nothing && return nothing
+    val, new_state = x
+    end_idx = state[2] + length(val) - 1
+    ((val, state[2], end_idx), (new_state, end_idx + 1))
+end