Start refactor (broken)

examples/01_basics/07_unions.py

@@ -23,7 +23,7 @@ class Color(enum.Enum):
 @dataclasses.dataclass(frozen=True)
 class Args:
     # Unions can be used to specify multiple allowable types.
-    union_over_types: int | str = 0
+    union_over_types: int | str
     string_or_enum: Literal["red", "green"] | Color = "red"
 
     # Unions also work over more complex nested types.

src/tyro/_arguments.py

@@ -108,7 +108,6 @@ class ArgumentDefinition:
     extern_prefix: str  # User-facing prefix.
     subcommand_prefix: str  # Prefix for nesting.
     field: _fields.FieldDefinition
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]]
 
     def add_argument(
         self, parser: Union[argparse.ArgumentParser, argparse._ArgumentGroup]
@@ -254,12 +253,7 @@ def _rule_handle_boolean_flags(
     arg: ArgumentDefinition,
     lowered: LoweredArgumentDefinition,
 ) -> None:
-    if (
-        _resolver.apply_type_from_typevar(
-            arg.field.type_or_callable, arg.type_from_typevar
-        )
-        is not bool
-    ):
+    if arg.field.type_or_callable is not bool:
         return
 
     if (
@@ -305,7 +299,6 @@ def _rule_recursive_instantiator_from_type(
     try:
         instantiator, metadata = _instantiators.instantiator_from_type(
             arg.field.type_or_callable,
-            arg.type_from_typevar,
             arg.field.markers,
         )
     except _instantiators.UnsupportedTypeAnnotationError as e:

src/tyro/_docstrings.py

@@ -301,7 +301,6 @@ def get_callable_description(f: Callable) -> str:
     the fields of the class if a docstring is not specified; this helper will ignore
     these docstrings."""
 
-    f, _unused = _resolver.resolve_generic_types(f)
     f = _resolver.unwrap_origin_strip_extras(f)
     if f in _callable_description_blocklist:
         return ""

src/tyro/_fields.py

@@ -44,14 +44,14 @@
     is_typeddict,
 )
 
+from . import conf  # Avoid circular import.
 from . import (
     _docstrings,
     _instantiators,
     _resolver,
     _singleton,
     _strings,
     _unsafe_cache,
-    conf,  # Avoid circular import.
 )
 from ._typing import TypeForm
 from .conf import _confstruct, _markers
@@ -109,9 +109,6 @@ def make(
         *,
         markers: Tuple[_markers.Marker, ...] = (),
     ):
-        # Resolve generic aliases.
-        type_or_callable = _resolver.apply_type_from_typevar(type_or_callable, {})
-
         # Try to extract argconf overrides from type.
         _, argconfs = _resolver.unwrap_annotated_and_aliases(
             type_or_callable, _confstruct._ArgConfiguration
@@ -147,6 +144,38 @@ def make(
         for context_markers in _field_context_markers:
             markers += context_markers
 
+        # Type resolution.
+        type_or_callable = _resolver.type_from_typevar_constraints(type_or_callable)
+        type_or_callable = _resolver.narrow_collection_types(type_or_callable, default)
+        type_or_callable = _resolver.narrow_union_type(type_or_callable, default)
+        type_or_callable = _resolver.apply_type_shims(type_or_callable)
+
+        # Check that the default value matches the final resolved type.
+        # There's some similar Union-specific logic for this in narrow_union_type(). We
+        # may be able to consolidate this.
+        if (
+            # Be relatively conservative: isinstance() can be checked on non-type
+            # types (like unions in Python >=3.10), but we'll only consider single types
+            # for now.
+            type(type_or_callable) is type
+            and not isinstance(default, type_or_callable)  # type: ignore
+            # If a custom constructor is set, type_or_callable may not be
+            # matched to the annotated type.
+            and argconf.constructor_factory is None
+            and default not in DEFAULT_SENTINEL_SINGLETONS
+            # The numeric tower in Python is wacky. This logic is non-critical, so
+            # we'll just skip it (+the complexity) for numbers.
+            and not isinstance(default, numbers.Number)
+        ):
+            # If the default value doesn't match the resolved type, we expand the
+            # type. This is inspired by https://github.com/brentyi/tyro/issues/88.
+            warnings.warn(
+                f"The field {name} is annotated with type {type_or_callable}, "
+                f"but the default value {default} has type {type(default)}. "
+                f"We'll try to handle this gracefully, but it may cause unexpected behavior."
+            )
+            type_or_callable = Union[type_or_callable, type(default)]  # type: ignore
+
         out = FieldDefinition(
             intern_name=name,
             extern_name=name if argconf.name is None else argconf.name,
@@ -271,9 +300,7 @@ def field_list_from_callable(
     f: Union[Callable, TypeForm[Any]],
     default_instance: DefaultInstance,
     support_single_arg_types: bool,
-) -> Tuple[
-    Union[Callable, TypeForm[Any]], Dict[TypeVar, TypeForm], List[FieldDefinition]
-]:
+) -> Tuple[Union[Callable, TypeForm[Any]], List[FieldDefinition]]:
     """Generate a list of generic 'field' objects corresponding to the inputs of some
     annotated callable.
 
@@ -283,7 +310,6 @@ def field_list_from_callable(
         A list of field definitions.
     """
     # Resolve generic types.
-    f, type_from_typevar = _resolver.resolve_generic_types(f)
     f = _resolver.unwrap_newtype_and_narrow_subtypes(f, default_instance)
 
     # Try to generate field list.
@@ -296,7 +322,6 @@ def field_list_from_callable(
         if support_single_arg_types:
             return (
                 f,
-                type_from_typevar,
                 [
                     FieldDefinition(
                         intern_name="value",
@@ -317,46 +342,7 @@ def field_list_from_callable(
         else:
             raise _instantiators.UnsupportedTypeAnnotationError(field_list.message)
 
-    # Try to resolve types in our list of fields.
-    def resolve(field: FieldDefinition) -> FieldDefinition:
-        typ = field.type_or_callable
-        typ = _resolver.apply_type_from_typevar(typ, type_from_typevar)
-        typ = _resolver.type_from_typevar_constraints(typ)
-        typ = _resolver.narrow_collection_types(typ, field.default)
-        typ = _resolver.narrow_union_type(typ, field.default)
-
-        # Check that the default value matches the final resolved type.
-        # There's some similar Union-specific logic for this in narrow_union_type(). We
-        # may be able to consolidate this.
-        if (
-            # Be relatively conservative: isinstance() can be checked on non-type
-            # types (like unions in Python >=3.10), but we'll only consider single types
-            # for now.
-            type(typ) is type
-            and not isinstance(field.default, typ)  # type: ignore
-            # If a custom constructor is set, field.type_or_callable may not be
-            # matched to the annotated type.
-            and not field.custom_constructor
-            and field.default not in DEFAULT_SENTINEL_SINGLETONS
-            # The numeric tower in Python is wacky. This logic is non-critical, so
-            # we'll just skip it (+the complexity) for numbers.
-            and not isinstance(field.default, numbers.Number)
-        ):
-            # If the default value doesn't match the resolved type, we expand the
-            # type. This is inspired by https://github.com/brentyi/tyro/issues/88.
-            warnings.warn(
-                f"The field {field.intern_name} is annotated with type {field.type_or_callable}, "
-                f"but the default value {field.default} has type {type(field.default)}. "
-                f"We'll try to handle this gracefully, but it may cause unexpected behavior."
-            )
-            typ = Union[typ, type(field.default)]  # type: ignore
-
-        field = dataclasses.replace(field, type_or_callable=typ)
-        return field
-
-    field_list = list(map(resolve, field_list))
-
-    return f, type_from_typevar, field_list
+    return f, field_list
 
 
 # Implementation details below.
@@ -396,8 +382,6 @@ def _try_field_list_from_callable(
         default_instance = found_subcommand_configs[0].default
 
     # Unwrap generics.
-    f, type_from_typevar = _resolver.resolve_generic_types(f)
-    f = _resolver.apply_type_from_typevar(f, type_from_typevar)
     f = _resolver.unwrap_newtype_and_narrow_subtypes(f, default_instance)
     f = _resolver.narrow_collection_types(f, default_instance)
     f_origin = _resolver.unwrap_origin_strip_extras(cast(TypeForm, f))
@@ -445,7 +429,12 @@ def _try_field_list_from_callable(
         dict,
     ):
         return _field_list_from_dict(f, default_instance)
-    elif f_origin in (list, set, typing.Sequence, collections.abc.Sequence) or cls in (
+    elif f_origin in (
+        list,
+        set,
+        typing.Sequence,
+        collections.abc.Sequence,
+    ) or cls in (
         list,
         set,
         typing.Sequence,

src/tyro/_instantiators.py

@@ -129,10 +129,6 @@ def is_type_string_converter(typ: Union[Callable, TypeForm[Any]]) -> bool:
     # Some checks we can do if the signature is available!
     for i, param in enumerate(signature.parameters.values()):
         annotation = type_annotations.get(param.name, param.annotation)
-
-        # Hack: apply_type_from_typevar applies shims, like UnionType => Union
-        # conversion.
-        annotation = _resolver.apply_type_from_typevar(annotation, {})
         if i == 0 and not (
             (get_origin(annotation) is Union and str in get_args(annotation))
             or annotation in (str, inspect.Parameter.empty)
@@ -153,7 +149,6 @@ def is_type_string_converter(typ: Union[Callable, TypeForm[Any]]) -> bool:
 
 def instantiator_from_type(
     typ: Union[TypeForm[Any], Callable],
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     markers: Set[_markers.Marker],
 ) -> Tuple[Instantiator, InstantiatorMetadata]:
     """Recursive helper for parsing type annotations.
@@ -201,9 +196,7 @@ def instantiator(strings: List[str]) -> None:
 
     # Address container types. If a matching container is found, this will recursively
     # call instantiator_from_type().
-    container_out = _instantiator_from_container_type(
-        cast(TypeForm[Any], typ), type_from_typevar, markers
-    )
+    container_out = _instantiator_from_container_type(cast(TypeForm[Any], typ), markers)
     if container_out is not None:
         return container_out
 
@@ -335,7 +328,6 @@ def instantiator_base_case(strings: List[str]) -> Any:
 @overload
 def _instantiator_from_type_inner(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     allow_sequences: Literal["fixed_length"],
     markers: Set[_markers.Marker],
 ) -> Tuple[Instantiator, InstantiatorMetadata]: ...
@@ -344,7 +336,6 @@ def _instantiator_from_type_inner(
 @overload
 def _instantiator_from_type_inner(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     allow_sequences: Literal[False],
     markers: Set[_markers.Marker],
 ) -> Tuple[_StandardInstantiator, InstantiatorMetadata]: ...
@@ -353,21 +344,19 @@ def _instantiator_from_type_inner(
 @overload
 def _instantiator_from_type_inner(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     allow_sequences: Literal[True],
     markers: Set[_markers.Marker],
 ) -> Tuple[Instantiator, InstantiatorMetadata]: ...
 
 
 def _instantiator_from_type_inner(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     allow_sequences: Literal["fixed_length", True, False],
     markers: Set[_markers.Marker],
 ) -> Tuple[Instantiator, InstantiatorMetadata]:
     """Thin wrapper over instantiator_from_type, with some extra asserts for catching
     errors."""
-    out = instantiator_from_type(typ, type_from_typevar, markers)
+    out = instantiator_from_type(typ, markers)
     if out[1].nargs == "*":
         # We currently only use allow_sequences=False for options in Literal types,
         # which are evaluated using `type()`. It should not be possible to hit this
@@ -384,7 +373,6 @@ def _instantiator_from_type_inner(
 
 def _instantiator_from_container_type(
     typ: TypeForm[Any],
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     markers: Set[_markers.Marker],
 ) -> Optional[Tuple[Instantiator, InstantiatorMetadata]]:
     """Attempt to create an instantiator from a container type. Returns `None` if no
@@ -418,13 +406,12 @@ def _instantiator_from_container_type(
         _instantiator_from_literal: (Literal, LiteralAlternate),
     }.items():
         if type_origin in matched_origins:
-            return make(typ, type_from_typevar, markers)
+            return make(typ, markers)
     return None
 
 
 def _instantiator_from_tuple(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     markers: Set[_markers.Marker],
 ) -> Tuple[Instantiator, InstantiatorMetadata]:
     types = get_args(typ)
@@ -435,15 +422,15 @@ def _instantiator_from_tuple(
         # Ellipsis: variable argument counts. When an ellipsis is used, tuples must
         # contain only one type.
         assert len(typeset_no_ellipsis) == 1
-        return _instantiator_from_sequence(typ, type_from_typevar, markers)
+        return _instantiator_from_sequence(typ, markers)
 
     else:
         instantiators: List[_StandardInstantiator] = []
         metas: List[InstantiatorMetadata] = []
         nargs = 0
         for t in types:
             a, b = _instantiator_from_type_inner(
-                t, type_from_typevar, allow_sequences="fixed_length", markers=markers
+                t, allow_sequences="fixed_length", markers=markers
             )
             instantiators.append(a)  # type: ignore
             metas.append(b)
@@ -509,7 +496,6 @@ def _join_union_metavars(metavars: Iterable[str]) -> str:
 
 def _instantiator_from_union(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     markers: Set[_markers.Marker],
 ) -> Tuple[Instantiator, InstantiatorMetadata]:
     options = list(get_args(typ))
@@ -528,9 +514,7 @@ def _instantiator_from_union(
     nargs: Optional[Union[int, Literal["*"]]] = 1
     first = True
     for t in options:
-        a, b = _instantiator_from_type_inner(
-            t, type_from_typevar, allow_sequences=True, markers=markers
-        )
+        a, b = _instantiator_from_type_inner(t, allow_sequences=True, markers=markers)
         instantiators.append(a)
         metas.append(b)
         if b.choices is None:
@@ -591,18 +575,16 @@ def union_instantiator(strings: List[str]) -> Any:
 
 def _instantiator_from_dict(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     markers: Set[_markers.Marker],
 ) -> Tuple[Instantiator, InstantiatorMetadata]:
     key_type, val_type = get_args(typ)
     key_instantiator, key_meta = _instantiator_from_type_inner(
-        key_type, type_from_typevar, allow_sequences="fixed_length", markers=markers
+        key_type, allow_sequences="fixed_length", markers=markers
     )
 
     if _markers.UseAppendAction in markers:
         val_instantiator, val_meta = _instantiator_from_type_inner(
             val_type,
-            type_from_typevar,
             allow_sequences=True,
             markers=markers - {_markers.UseAppendAction},
         )
@@ -625,7 +607,7 @@ def append_dict_instantiator(strings: List[List[str]]) -> Any:
         )
     else:
         val_instantiator, val_meta = _instantiator_from_type_inner(
-            val_type, type_from_typevar, allow_sequences="fixed_length", markers=markers
+            val_type, allow_sequences="fixed_length", markers=markers
         )
         pair_metavar = f"{key_meta.metavar} {val_meta.metavar}"
         key_nargs = cast(int, key_meta.nargs)  # Casts needed for mypy but not pyright!
@@ -673,7 +655,6 @@ def dict_instantiator(strings: List[str]) -> Any:
 
 def _instantiator_from_sequence(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     markers: Set[_markers.Marker],
 ) -> Tuple[Instantiator, InstantiatorMetadata]:
     """Instantiator for variable-length sequences: list, sets, Tuple[T, ...], etc."""
@@ -691,7 +672,6 @@ def _instantiator_from_sequence(
     if _markers.UseAppendAction in markers:
         make, inner_meta = _instantiator_from_type_inner(
             contained_type,
-            type_from_typevar,
             allow_sequences=True,
             markers=markers - {_markers.UseAppendAction},
         )
@@ -709,7 +689,6 @@ def append_sequence_instantiator(strings: List[List[str]]) -> Any:
     else:
         make, inner_meta = _instantiator_from_type_inner(
             contained_type,
-            type_from_typevar,
             allow_sequences="fixed_length",
             markers=markers,
         )
@@ -743,7 +722,6 @@ def sequence_instantiator(strings: List[str]) -> Any:
 
 def _instantiator_from_literal(
     typ: TypeForm,
-    type_from_typevar: Dict[TypeVar, TypeForm[Any]],
     markers: Set[_markers.Marker],
 ) -> Tuple[_StandardInstantiator, InstantiatorMetadata]:
     choices = get_args(typ)