make the parametric type of CachedMapper to be the return type

pytato/codegen.py

@@ -83,7 +83,8 @@ def _generate_name_for_temp(
 
 # {{{ preprocessing for codegen
 
-class CodeGenPreprocessor(ToIndexLambdaMixin, CopyMapper):
+# type-ignore-reason: incompatible 'rec' types between ToIndexLambdaMixin, CopyMapper
+class CodeGenPreprocessor(ToIndexLambdaMixin, CopyMapper):  # type: ignore[misc]
     """A mapper that preprocesses graphs to simplify code generation.
 
     The following node simplifications are performed:

pytato/distributed/partition.py

@@ -50,7 +50,7 @@
                           NamedArray)
 from pytato.transform import (ArrayOrNames, CopyMapper, Mapper,
                               CachedWalkMapper, CopyMapperWithExtraArgs,
-                              CombineMapper)
+                              CombineMapper, CopyMapperT)
 from pytato.partition import GraphPart, GraphPartition, PartId, GraphPartitioner
 from pytato.distributed.nodes import (
         DistributedRecv, DistributedSend, DistributedSendRefHolder)
@@ -233,10 +233,12 @@ def __init__(self, get_part_id: Callable[[ArrayOrNames], PartId]) -> None:
     def map_distributed_send_ref_holder(
                 self, expr: DistributedSendRefHolder, *args: Any) -> Any:
         send_part_id = self.get_part_id(expr.send.data)
+        rec_send_data = self.rec(expr.send.data)
+        assert isinstance(rec_send_data, Array)
 
         self.pid_to_dist_sends.setdefault(send_part_id, []).append(
                 DistributedSend(
-                    data=self.rec(expr.send.data),
+                    data=rec_send_data,
                     dest_rank=expr.send.dest_rank,
                     comm_tag=expr.send.comm_tag,
                     tags=expr.send.tags))
@@ -560,7 +562,7 @@ def __init__(self,
 
         # type-ignore reason: incompatible  attribute type wrt base.
         self._cache: Dict[Tuple[ArrayOrNames, int],
-                          Any] = {}  # type: ignore[assignment]
+                          ArrayOrNames] = {}  # type: ignore[assignment]
 
     # type-ignore-reason: incompatible with super class
     def get_cache_key(self,  # type: ignore[override]
@@ -572,11 +574,12 @@ def get_cache_key(self,  # type: ignore[override]
 
     # type-ignore-reason: incompatible with super class
     def rec(self,  # type: ignore[override]
-            expr: ArrayOrNames,
-            user_part_id: int) -> Any:
+            expr: CopyMapperT,
+            user_part_id: int) -> CopyMapperT:
         key = self.get_cache_key(expr, user_part_id)
         try:
-            return self._cache[key]
+            # type-ignore-reason: parametric dicts are not a thing in typing module
+            return self._cache[key]  # type: ignore[return-value]
         except KeyError:
             if isinstance(expr, Array):
                 if expr in self.stored_array_to_part_id:
@@ -592,6 +595,12 @@ def rec(self,  # type: ignore[override]
             self._cache[key] = result
             return result
 
+    # type-ignore-reason: incompatible with super class
+    def __call__(self,  # type: ignore[override]
+                 expr: CopyMapperT,
+                 user_part_id: int) -> CopyMapperT:
+        return self.rec(expr, user_part_id)
+
 
 def _remove_part_id_tag(ary: ArrayOrNames) -> Array:
     assert isinstance(ary, Array)

pytato/partition.py

@@ -161,7 +161,10 @@ def handle_edge(self, expr: ArrayOrNames, child: ArrayOrNames) -> Any:
                                       tags=child.tags,
                                       axes=child.axes)
 
-                self.var_name_to_result[ph_name] = self.rec(child)
+                # type-ignore-reason: mypy is right, types of self.rec are
+                # imprecise (TODO)
+                self.var_name_to_result[ph_name] = (
+                    self.rec(child))  # type: ignore[assignment]
 
                 self._seen_node_to_placeholder[child] = ph
 

pytato/target/python/numpy_like.py

@@ -31,7 +31,7 @@
                     cast, List, Set, Tuple, Type)
 
 from pytools import UniqueNameGenerator
-from pytato.transform import CachedMapper, ArrayOrNames
+from pytato.transform import CachedMapper
 from pytato.array import (Stack, Concatenate, IndexLambda, DataWrapper,
                           Placeholder, SizeParam, Roll,
                           AxisPermutation, Einsum,
@@ -164,7 +164,7 @@ def _is_slice_trivial(slice_: NormalizedSlice,
 }
 
 
-class NumpyCodegenMapper(CachedMapper[ArrayOrNames]):
+class NumpyCodegenMapper(CachedMapper[str]):
     """
     .. note::
 
@@ -408,7 +408,7 @@ def _map_index_base(self, expr: IndexBase) -> str:
         )
 
         if last_non_trivial_index == -1:
-            return self.rec(expr.array)  # type: ignore[no-any-return]
+            return self.rec(expr.array)
 
         lhs = self.vng("_pt_tmp")
 
@@ -500,8 +500,7 @@ def map_reshape(self, expr: Reshape) -> str:
         return self._record_line_and_return_lhs(lhs, rhs)
 
     def map_named_array(self, expr: NamedArray) -> str:
-        # type-ignore-reason: CachedMapper.rec's types are imprecise
-        return self.rec(expr.expr)  # type: ignore[no-any-return]
+        return self.rec(expr.expr)
 
     def map_dict_of_named_arrays(self, expr: DictOfNamedArrays) -> str:
         lhs = self.vng("_pt_tmp")

pytato/transform/__init__.py

@@ -49,8 +49,11 @@
 from pymbolic.mapper.optimize import optimize_mapper
 
 ArrayOrNames = Union[Array, AbstractResultWithNamedArrays]
-MappedT = TypeVar("MappedT", bound=ArrayOrNames)
+MappedT = TypeVar("MappedT",
+                  Array, AbstractResultWithNamedArrays, ArrayOrNames)
 CombineT = TypeVar("CombineT")  # used in CombineMapper
+CopyMapperT = TypeVar("CopyMapperT",  # used in CopyMapper
+                      Array, AbstractResultWithNamedArrays, ArrayOrNames)
 CachedMapperT = TypeVar("CachedMapperT")  # used in CachedMapper
 IndexOrShapeExpr = TypeVar("IndexOrShapeExpr")
 R = FrozenSet[Array]
@@ -180,20 +183,26 @@ class CachedMapper(Mapper, Generic[CachedMapperT]):
     """
 
     def __init__(self) -> None:
-        self._cache: Dict[CachedMapperT, Any] = {}
+        self._cache: Dict[Any, CachedMapperT] = {}
 
-    def get_cache_key(self, expr: CachedMapperT) -> Any:
+    def get_cache_key(self, expr: ArrayOrNames) -> Any:
         return expr
 
     # type-ignore-reason: incompatible with super class
-    def rec(self, expr: CachedMapperT) -> Any:  # type: ignore[override]
+    def rec(self, expr: ArrayOrNames) -> CachedMapperT:  # type: ignore[override]
         key = self.get_cache_key(expr)
         try:
             return self._cache[key]
         except KeyError:
-            result = super().rec(expr)  # type: ignore[type-var]
+            result = super().rec(expr)
             self._cache[key] = result
-            return result
+            # type-ignore-reason: Mapper.rec has imprecise func. signature
+            return result  # type: ignore[no-any-return]
+
+    # type-ignore-reason: incompatible with super class
+    def __call__(self, expr: ArrayOrNames  # type: ignore[override]
+                 ) -> CachedMapperT:
+        return self.rec(expr)
 
 # }}}
 
@@ -210,9 +219,21 @@ class CopyMapper(CachedMapper[ArrayOrNames]):
        This does not copy the data of a :class:`pytato.array.DataWrapper`.
     """
 
+    # type-ignore-reason: specialized variant of super-class' rec method
+    def rec(self, expr: CopyMapperT) -> CopyMapperT:  # type: ignore[override]
+        # type-ignore-reason: CachedMapper.rec's return type is imprecise
+        return super().rec(expr)  # type: ignore[return-value]
+
+    # type-ignore-reason: specialized variant of super-class' rec method
+    def __call__(self, expr: CopyMapperT) -> CopyMapperT:  # type: ignore[override]
+        return self.rec(expr)
+
     def rec_idx_or_size_tuple(self, situp: Tuple[IndexOrShapeExpr, ...]
                               ) -> Tuple[IndexOrShapeExpr, ...]:
-        return tuple(self.rec(s) if isinstance(s, Array) else s for s in situp)
+        # type-ignore-reason: apparently mypy cannot substitute typevars
+        # here.
+        return tuple(self.rec(s) if isinstance(s, Array) else s  # type: ignore[misc]
+                     for s in situp)
 
     def map_index_lambda(self, expr: IndexLambda) -> Array:
         bindings: Dict[str, Array] = {
@@ -319,8 +340,10 @@ def map_loopy_call(self, expr: LoopyCall) -> LoopyCall:
                          )
 
     def map_loopy_call_result(self, expr: LoopyCallResult) -> Array:
+        rec_container = self.rec(expr._container)
+        assert isinstance(rec_container, LoopyCall)
         return LoopyCallResult(
-                loopy_call=self.rec(expr._container),
+                loopy_call=rec_container,
                 name=expr.name,
                 axes=expr.axes,
                 tags=expr.tags)
@@ -364,7 +387,7 @@ def __init__(self) -> None:
                                 Tuple[Any, ...],
                                 Tuple[Tuple[str, Any], ...]
                                 ],
-                          Any] = {}  # type: ignore[assignment]
+                          ArrayOrNames] = {}
 
     def get_cache_key(self,
                       expr: ArrayOrNames,
@@ -375,23 +398,30 @@ def get_cache_key(self,
         return (expr, args, tuple(sorted(kwargs.items())))
 
     def rec(self,
-            expr: ArrayOrNames,
-            *args: Any, **kwargs: Any) -> Any:
+            expr: CopyMapperT,
+            *args: Any, **kwargs: Any) -> CopyMapperT:
         key = self.get_cache_key(expr, *args, **kwargs)
         try:
-            return self._cache[key]
+            # type-ignore-reason: self._cache has ArrayOrNames as its values
+            return self._cache[key]  # type: ignore[return-value]
         except KeyError:
             result = Mapper.rec(self, expr,
                                 *args,
                                 **kwargs)
             self._cache[key] = result
-            return result
+            # type-ignore-reason: Mapper.rec is imprecise
+            return result  # type: ignore[no-any-return]
 
     def rec_idx_or_size_tuple(self, situp: Tuple[IndexOrShapeExpr, ...],
                               *args: Any, **kwargs: Any
                               ) -> Tuple[IndexOrShapeExpr, ...]:
-        return tuple(self.rec(s, *args, **kwargs) if isinstance(s, Array) else s
-                     for s in situp)
+        # type-ignore-reason: apparently mypy cannot substitute typevars
+        # here.
+        return tuple(
+            self.rec(s, *args, **kwargs)  # type: ignore[misc]
+            if isinstance(s, Array)
+            else s
+            for s in situp)
 
     def map_index_lambda(self, expr: IndexLambda,
                          *args: Any, **kwargs: Any) -> Array:
@@ -510,8 +540,10 @@ def map_loopy_call(self, expr: LoopyCall,
 
     def map_loopy_call_result(self, expr: LoopyCallResult,
                               *args: Any, **kwargs: Any) -> Array:
+        rec_loopy_call = self.rec(expr._container, *args, **kwargs)
+        assert isinstance(rec_loopy_call, LoopyCall)
         return LoopyCallResult(
-                loopy_call=self.rec(expr._container, *args, **kwargs),
+                loopy_call=rec_loopy_call,
                 name=expr.name,
                 axes=expr.axes,
                 tags=expr.tags)
@@ -1018,11 +1050,11 @@ def __init__(self, map_fn: Callable[[ArrayOrNames], ArrayOrNames]) -> None:
     # type-ignore-reason:incompatible with Mapper.rec()
     def rec(self, expr: ArrayOrNames) -> ArrayOrNames:  # type: ignore[override]
         if expr in self._cache:
-            return self._cache[expr]  # type: ignore[no-any-return]
+            return self._cache[expr]
 
         result = super().rec(self.map_fn(expr))
         self._cache[expr] = result
-        return result  # type: ignore[no-any-return]
+        return result
 
     # type-ignore-reason: Mapper.__call__ returns Any
     def __call__(self, expr: ArrayOrNames) -> ArrayOrNames:  # type: ignore[override]

pytato/transform/remove_broadcasts_einsum.py

@@ -96,8 +96,6 @@ def rewrite_einsums_with_no_broadcasts(expr: MappedT) -> MappedT:
         alter its value.
     """
     mapper = EinsumWithNoBroadcastsRewriter()
-
-    # type-ignore-reason: mypy is right i.e. CopyMapper.__call__ is imprecise
-    return mapper(expr)  # type: ignore[no-any-return]
+    return mapper(expr)
 
 # vim:fdm=marker