bug - Decorator callable metadata still fails for imported partial defaults and alias callables

[dannymeijer]

Thanks for reporting! Please include a minimal reproduction when possible.

Area

• Incan Language (syntax/semantics)
• Compiler (frontend/backend/codegen)

Summary

Expected: after #700 closed #694 and #698, decorator-backed registries should be able to combine imported public partial presets with decorated callable identity. In particular, a decorator argument such as an imported partial preset should preserve and qualify its captured defaults, and generic decorator helpers that read func.__name__ should work for callables whose signatures use imported aliases/unions.

Actual: release/v0.3 at c1b460d8 (incan 0.3.0-rc18) still fails on the broader InQL registry shape. Generated Rust loses qualification for symbols captured by imported partial defaults and emits invalid callable-name support for alias/union-expanded and async/generic callable shapes.

This blocks verification of InQL PR #44 after removing duplicated registry canonical-name arguments.

Related: #694, #698, #700, and broad follow-up #699.

Reproduction steps

Broad InQL reproducer

1. Check out dannys-code-corner/InQL branch feature/33-35-41-wave1-function-catalog.
2. Check out dannys-code-corner/incan branch release/v0.3 at c1b460d8 and build the incan binary.
3. From the InQL checkout, run:

incan test tests/test_substrait_plan.incn

4. The generated Rust test harness fails during preheat before any InQL assertions run.

Minimal imported partial default reproducer

Create src/registry.incn:

pub const DEFAULT_NAMESPACE: str = "core"


pub enum Policy(str):
  Portable = "portable"


pub model Spec:
  pub namespace: str
  pub policy: Policy
  pub lifecycle: str


pub static namespaces: list[str] = []
pub static names: list[str] = []


pub spec = partial Spec(namespace=DEFAULT_NAMESPACE, policy=Policy.Portable)


pub def capture(func: (int) -> int) -> ((int) -> int):
  names.append(func.__name__)
  return func


pub def add(spec_value: Spec) -> (((int) -> int) -> ((int) -> int)):
  namespaces.append(spec_value.namespace)
  return capture

Create src/helpers.incn:

from registry import add, spec


@add(spec(lifecycle="v1"))
pub def sample(value: int) -> int:
  return value + 1

Create tests/test_partial_default_symbols.incn:

from helpers import sample
from registry import names, namespaces


def test_partial_default_symbols_in_decorator() -> None:
  assert sample(1) == 2
  assert names[0] == "sample"
  assert namespaces[0] == "core"

Run:

incan test tests/test_partial_default_symbols.incn

Expected: test passes and the imported partial preset preserves DEFAULT_NAMESPACE and Policy.Portable inside the decorator argument.

Actual: generated Rust refers to captured default symbols from the wrong module scope.

Minimal alias/union callable-name reproducer

Create src/types.incn:

pub model A:
  pub value: int


pub model B:
  pub value: int


pub type Expr = Union[A, B]

Create src/registry.incn:

pub static names: list[str] = []


pub def capture[F](func: F) -> F:
  names.append(func.__name__)
  return func


pub def register[F]() -> ((F) -> F):
  return (func) => capture[F](func)

Create src/helpers.incn:

from registry import register
from types import Expr


@register[(Expr) -> Expr]()
pub def identity_expr(value: Expr) -> Expr:
  return value

Create tests/test_alias_union_callable_name.incn:

from helpers import identity_expr
from registry import names
from types import A


def test_alias_union_callable_name() -> None:
  identity_expr(A(value=1))
  assert names[0] == "identity_expr", names[0]

Run:

incan test tests/test_alias_union_callable_name.incn

Expected: test passes and the generic decorator can read the decorated callable name.

Actual: generated callable-name support references alias/union types from the wrong scope or expands them into conflicting callable-name impls in larger packages.

Output / logs

Representative broad InQL errors after #700:

error[E0425]: cannot find type `RejectedFunctionPolicy` in this scope
error[E0425]: cannot find value `CORE_FUNCTION_NAMESPACE` in this scope
error[E0119]: conflicting implementations of trait `__IncanCallableName` for type `fn(__IncanUnion...) -> __IncanUnion...`
error[E0605]: non-primitive cast: `fn() -> impl Future<Output = ()> ...` as `fn()`

The first two errors come from imported partial/default qualification. The __IncanCallableName conflicts and async casts come from callable-name metadata generation being applied too broadly or with the wrong lowered callable shape.

Environment

OS: macOS
Rust: stable toolchain used by release/v0.3
Incan: release/v0.3 at c1b460d8, incan 0.3.0-rc18
Command: incan test tests/test_substrait_plan.incn from the InQL branch feature/33-35-41-wave1-function-catalog
Blocking status: blocks InQL PR #44 verification after applying the intended ambient decorator-name and imported-partial registry shape.