Simplify BlockSplitter's iterator implementation

httomo/runner/block_split.py

@@ -1,5 +1,4 @@
 import math
-from typing import Iterator
 from httomo.runner.dataset import DataSetBlock
 from httomo.runner.dataset_store_interfaces import DataSetSource
 
@@ -22,6 +21,7 @@ def __init__(self, source: DataSetSource, max_slices: int):
         self._chunk_size = source.chunk_shape[source.slicing_dim]
         self._max_slices = int(min(max_slices, self._chunk_size))
         self._num_blocks = math.ceil(self._chunk_size / self._max_slices)
+        self._current = 0
         assert self._source.slicing_dim in [
             0,
             1,
@@ -41,20 +41,12 @@ def __getitem__(self, idx: int) -> DataSetBlock:
         len = min(self.slices_per_block, self._chunk_size - start)
         return self._source.read_block(start, len)
 
-    def __iter__(self) -> Iterator[DataSetBlock]:
-        class BlockIterator:
-            def __init__(self, splitter):
-                self.splitter = splitter
-                self._current = 0
+    def __iter__(self):
+        return self
 
-            def __iter__(self) -> "BlockIterator":
-                return self  # pragma: no cover
-
-            def __next__(self) -> DataSetBlock:
-                if self._current >= len(self.splitter):
-                    raise StopIteration
-                v = self.splitter[self._current]
-                self._current += 1
-                return v
-
-        return BlockIterator(self)
+    def __next__(self) -> DataSetBlock:
+        if self._current >= len(self):
+            raise StopIteration
+        v = self[self._current]
+        self._current += 1
+        return v