Frequently Encountered Lazy Evaluation Gotchas¶
Handling RecursionError¶
Errors such as “RecursionError: maximum recursion depth exceeded” are seen when the computation graph for which code is being generated for has a path of the order of 1000 intermediate arrays. Following remedies may be helpful:
Assessing if the same result can be achieved with fewer number of array operations.
Increasing the recursion limit via
sys.setrecursionlimit().Checking for any broken memoization implementation in the sub-classed
pytato.transform.Mapper.
Traversal order in a pytato.transform.Mapper¶
Although the direction of our DAG is similar to a data-flow graph, the
traversal order in mapper is the opposite way around i.e. the mapper method of
a node’s user would be entered before the node’s mapper method. However, the
mapper method of a node would be returned before it’s user’s mapper method is
returned. Similar traversal order is routinely seen in visitors of other packages like
pymbolic, pycparser, etc.