Require that happens_after is not mutable

loopy/kernel/instruction.py

@@ -20,7 +20,11 @@
 THE SOFTWARE.
 """
 
-from collections.abc import Mapping as MappingABC, Set as abc_Set
+from collections.abc import (
+ Mapping as MappingABC,
+ MutableMapping as MutableMappingABC,
+ Set as abc_Set,
+)
 from dataclasses import dataclass
 from functools import cached_property
 from sys import intern
@@ -283,6 +287,7 @@ def __init__(self,
  *,
  depends_on: Union[FrozenSet[str], str, None] = None,
  ) -> None:
+ from immutabledict import immutabledict
 
  if predicates is None:
  predicates = frozenset()
@@ -315,27 +320,27 @@ def __init__(self,
  "actually specifying happens_after/depends_on")
 
  if happens_after is None:
- happens_after = {}
+ happens_after = immutabledict()
  elif isinstance(happens_after, str):
  warn("Passing a string for happens_after/depends_on is deprecated and "
  "will stop working in 2025. Instead, pass a full-fledged "
  "happens_after data structure.", DeprecationWarning, stacklevel=2)
 
- happens_after = {
+ happens_after = immutabledict({
  after_id.strip(): HappensAfter(
  variable_name=None,
  instances_rel=None)
  for after_id in happens_after.split(",")
- if after_id.strip()}
+ if after_id.strip()})
  elif isinstance(happens_after, frozenset):
- happens_after = {
+ happens_after = immutabledict({
  after_id: HappensAfter(
  variable_name=None,
  instances_rel=None)
- for after_id in happens_after}
+ for after_id in happens_after})
  elif isinstance(happens_after, MappingABC):
  if isinstance(happens_after, dict):
- happens_after = happens_after
+ happens_after = immutabledict(happens_after)
  else:
  raise TypeError("'happens_after' has unexpected type: "
  f"{type(happens_after)}")
@@ -389,6 +394,9 @@ def __init__(self,
  assert isinstance(happens_after, MappingABC) or happens_after is None
  assert isinstance(groups, abc_Set)
  assert isinstance(conflicts_with_groups, abc_Set)
+ if isinstance(happens_after, MappingABC):
+ # Verify that happens_after is hashable.
+ assert not isinstance(happens_after, MutableMappingABC)
 
  ImmutableRecord.__init__(self,
  id=id,
@@ -573,13 +581,15 @@ def update_persistent_hash(self, key_hash, key_builder):
  def __setstate__(self, val):
  super().__setstate__(val)
 
+ from immutabledict import immutabledict
+
  from loopy.tools import intern_frozenset_of_ids
 
  if self.id is not None: # pylint:disable=access-member-before-definition
  self.id = intern(self.id)
- self.happens_after = {
+ self.happens_after = immutabledict({
  intern(after_id): ha
- for after_id, ha in self.happens_after.items()}
+ for after_id, ha in self.happens_after.items()})
  self.groups = intern_frozenset_of_ids(self.groups)
  self.conflicts_with_groups = (
  intern_frozenset_of_ids(self.conflicts_with_groups))

pyproject.toml

@@ -45,6 +45,7 @@ dependencies = [
  "Mako",
  "pyrsistent",
  "immutables",
+ "immutabledict",
 
  # for Self, TypeAlias
  "typing-extensions>=4; python_version<'3.12'",