# Copyright 2025 qBraid
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Module defining function annotations (e.g. decorators) used in the transpiler.
"""
from functools import wraps
from typing import Any, Callable, TypeVar, cast
F = TypeVar("F", bound=Callable[..., Any])
def weight(value: float) -> Callable[[F], F]:
"""
Decorator factory to mark conversion functions with a weight attribute.
This weight attribute is used to prioritize conversion paths in a conversion graph.
Args:
value (float): The weight of the conversion function. Must be between 0 and 1 inclusive.
Returns:
Callable: A decorator that assigns the specified weight to a function.
"""
if not 0 <= value <= 1:
raise ValueError("Weight value must be between 0 and 1.")
def decorator(func: F) -> F:
@wraps(func)
def wrapper(*args: Any, **kwargs: Any) -> Any:
return func(*args, **kwargs)
setattr(wrapper, "weight", value)
return cast(F, wrapper)
return decorator