Address review comments.

src/gt4py/next/iterator/transforms/infer_domain.py

@@ -30,7 +30,7 @@ class DomainAccessDescriptor(eve.StrEnum):
     Descriptor for domains that could not be inferred.
     """
 
-    #: The access if unknown because of a dynamic shift.whose extent is not known.
+    #: The access is unknown because of a dynamic shift.whose extent is not known.
     #: E.g.: `(⇑(λ(arg0, arg1) → ·⟪Ioffₒ, ·arg1⟫(arg0)))(in_field1, in_field2)`
     UNKNOWN = "unknown"
     #: The domain is never accessed.
@@ -83,7 +83,7 @@ def _domain_union(
         return DomainAccessDescriptor.UNKNOWN
 
     filtered_domains: list[domain_utils.SymbolicDomain] = [
-        d  # type: ignore[misc]  # domain can never be unknown because as these cases are filtered above
+        d  # type: ignore[misc]  # domain can never be unknown as these cases are filtered above
         for d in domains
         if d != DomainAccessDescriptor.NEVER
     ]
@@ -153,7 +153,6 @@ def _extract_accessed_domains(
     target_domain: domain_utils.SymbolicDomain | DomainAccessDescriptor,
     offset_provider: common.OffsetProvider,
     symbolic_domain_sizes: Optional[dict[str, str]],
-    allow_uninferred: bool,
 ) -> ACCESSED_DOMAINS:
     accessed_domains: dict[str, domain_utils.SymbolicDomain | DomainAccessDescriptor] = {}
 
@@ -178,6 +177,8 @@ def _extract_accessed_domains(
             accessed_domains.get(in_field_id, DomainAccessDescriptor.NEVER), *new_domains
         )
 
+    # Widen type to allow callee to all other types that can be in ACCESSED_DOMAINS, i.e. tuple.
+    # Fine since we transfer ownership of return value to callee.
     return typing.cast(ACCESSED_DOMAINS, accessed_domains)
 
 
@@ -196,10 +197,7 @@ def _infer_as_fieldop(
     # FIXME[#1582](tehrengruber): Temporary solution for `tuple_get` on scan result. See `test_solve_triag`.
     if isinstance(target_domain, tuple):
         target_domain = _domain_union(*flatten_nested_tuple(target_domain))  # type: ignore[arg-type]  # mypy not smart enough
-    if not isinstance(target_domain, (domain_utils.SymbolicDomain, DomainAccessDescriptor)):
-        raise ValueError(
-            "'target_domain' needs to be a 'domain_utils.SymbolicDomain' or a 'DomainAccessDescriptor'."
-        )
+    assert isinstance(target_domain, (domain_utils.SymbolicDomain, DomainAccessDescriptor))
 
     # `as_fieldop(stencil)(inputs...)`
     stencil, inputs = applied_fieldop.fun.args[0], applied_fieldop.args
@@ -222,7 +220,7 @@ def _infer_as_fieldop(
         input_ids.append(id_)
 
     inputs_accessed_domains: ACCESSED_DOMAINS = _extract_accessed_domains(
-        stencil, input_ids, target_domain, offset_provider, symbolic_domain_sizes, allow_uninferred
+        stencil, input_ids, target_domain, offset_provider, symbolic_domain_sizes
     )
 
     # Recursively infer domain of inputs and update domain arg of nested `as_fieldop`s
@@ -406,7 +404,7 @@ def infer_expr(
     - symbolic_domain_sizes: A dictionary mapping axes names, e.g., `I`, `Vertex`, to a symbol
       name that evaluates to the length of that axis.
     - allow_uninferred: Allow `as_fieldop` expressions whose domain is either unknown (e.g.
-      because of a dynamic shift) or empty.
+      because of a dynamic shift) or never accessed.
 
     Returns:
       A tuple containing the inferred expression with all applied `as_fieldop` (that are accessed)