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Task

BaseAsyncTask

Bases: ABC, Generic[T, E]

Abstract base class for async tasks that operate entirely on Result[T, E].

Each task receives a Result, processes it (if Ok), and returns a new Result.

Source code in neopipe/task.py 
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class BaseAsyncTask(ABC, Generic[T, E]):
    """
    Abstract base class for async tasks that operate entirely on Result[T, E].

    Each task receives a Result, processes it (if Ok), and returns a new Result.
    """

    def __init__(self, retries: int = 1):
        self.retries = retries
        self.task_id = uuid.uuid4()

    @property
    def task_name(self) -> str:
        """Returns a human-readable task name."""
        return self.__class__.__name__

    async def __call__(self, input_result: Result[T, E]) -> Result[U, E]:
        """
        Executes the task with retry logic.

        Args:
            input_result (Result[T, E]): The input Result from a previous task.

        Returns:
            Result[U, E]: Final task result after retry handling.
        """
        last_exception: Optional[Exception] = None

        for attempt in range(1, self.retries + 1):
            try:
                logger.info(
                    f"[{self.task_name}] Attempt {attempt} - Task ID: {self.task_id}"
                )
                result = await self.execute(input_result)

                if result.is_ok():
                    logger.info(f"[{self.task_name}] Success on attempt {attempt}")
                    return result
                else:
                    logger.warning(f"[{self.task_name}] Returned Err: {result.err()}")
                    return result

            except Exception as e:
                last_exception = e
                logger.exception(f"[{self.task_name}] Exception on attempt {attempt}")
                await asyncio.sleep(2 ** (attempt - 1))  # exponential backoff
        # tb = traceback.format_exception(
        #     last_exception.__class__, last_exception, last_exception.__traceback__
        # )
        return Err(
            f"[{self.task_name}] failed after {self.retries} retries and raised Error: {last_exception} with Exception type: {last_exception.__class__.__name__}."
        )

    @abstractmethod
    async def execute(self, input_result: Result[T, E]) -> Result[U, E]:
        """
        Async task execution logic that must be overridden.

        Args:
            input_result (Result[T, E]): The input Result.

        Returns:
            Result[U, E]: The output Result.
        """
        pass

    def __str__(self) -> str:
        return f"{self.task_name}(ID={self.task_id})"

    def __repr__(self) -> str:
        return self.__str__()

task_name property

Returns a human-readable task name.

__call__(input_result) async

Executes the task with retry logic.

Parameters:

Name Type Description Default
input_result Result[T, E]

The input Result from a previous task.

 required

Returns:

Type Description
Result[U, E]

Result[U, E]: Final task result after retry handling.
Source code in neopipe/task.py 
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async def __call__(self, input_result: Result[T, E]) -> Result[U, E]:
    """
    Executes the task with retry logic.

    Args:
        input_result (Result[T, E]): The input Result from a previous task.

    Returns:
        Result[U, E]: Final task result after retry handling.
    """
    last_exception: Optional[Exception] = None

    for attempt in range(1, self.retries + 1):
        try:
            logger.info(
                f"[{self.task_name}] Attempt {attempt} - Task ID: {self.task_id}"
            )
            result = await self.execute(input_result)

            if result.is_ok():
                logger.info(f"[{self.task_name}] Success on attempt {attempt}")
                return result
            else:
                logger.warning(f"[{self.task_name}] Returned Err: {result.err()}")
                return result

        except Exception as e:
            last_exception = e
            logger.exception(f"[{self.task_name}] Exception on attempt {attempt}")
            await asyncio.sleep(2 ** (attempt - 1))  # exponential backoff
    # tb = traceback.format_exception(
    #     last_exception.__class__, last_exception, last_exception.__traceback__
    # )
    return Err(
        f"[{self.task_name}] failed after {self.retries} retries and raised Error: {last_exception} with Exception type: {last_exception.__class__.__name__}."
    )

execute(input_result) abstractmethod async

Async task execution logic that must be overridden.

Parameters:

Name Type Description Default
input_result Result[T, E]

The input Result.

 required

Returns:

Type Description
Result[U, E]

Result[U, E]: The output Result.
Source code in neopipe/task.py 
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@abstractmethod
async def execute(self, input_result: Result[T, E]) -> Result[U, E]:
    """
    Async task execution logic that must be overridden.

    Args:
        input_result (Result[T, E]): The input Result.

    Returns:
        Result[U, E]: The output Result.
    """
    pass

BaseSyncTask

Bases: ABC, Generic[T, E]

Abstract base class for synchronous tasks that operate entirely on Result[T, E].

Each task receives a Result object, processes it (if Ok), and returns a new Result. Retry logic, logging, and task identification are handled automatically.

Attributes:

Name Type Description
retries int

Number of retry attempts if execution fails.
task_id UUID

Unique identifier for the task instance.
Source code in neopipe/task.py 
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class BaseSyncTask(ABC, Generic[T, E]):
    """
    Abstract base class for synchronous tasks that operate entirely on Result[T, E].

    Each task receives a Result object, processes it (if Ok), and returns a new Result.
    Retry logic, logging, and task identification are handled automatically.

    Attributes:
        retries (int): Number of retry attempts if execution fails.
        task_id (UUID): Unique identifier for the task instance.
    """

    def __init__(self, retries: int = 1):
        self.retries = retries
        self.task_id = uuid.uuid4()

    @property
    def task_name(self) -> str:
        """Returns a human-readable task name."""
        return self.__class__.__name__

    def __call__(self, input_result: Result[T, E]) -> Result[U, E]:
        """
        Executes the task with retry logic.

        Args:
            input_result (Result[T, E]): The input wrapped in a Result.

        Returns:
            Result[U, E]: The result of the task, either Ok or Err.
        """
        last_exception: Optional[Exception] = None

        for attempt in range(1, self.retries + 1):
            try:
                logger.info(
                    f"[{self.task_name}] Attempt {attempt} - Task ID: {self.task_id}"
                )
                result = self.execute(input_result)

                if result.is_ok():
                    logger.info(f"[{self.task_name}] Success on attempt {attempt}")
                    return result
                else:
                    logger.error(f"[{self.task_name}] Returned Err: {result.err()}")
                    return result

            except Exception as e:
                last_exception = e
                logger.exception(f"[{self.task_name}] Exception on attempt {attempt}")
                time.sleep(2 ** (attempt - 1))  # Exponential backoff

        return Err(
            f"[{self.task_name}] failed after {self.retries} retries and raised Error: {last_exception} with Exception type: {last_exception.__class__.__name__}."
        )

    @abstractmethod
    def execute(self, input_result: Result[T, E]) -> Result[U, E]:
        """
        Override this method in subclasses or function wrappers.

        Args:
            input_result (Result[T, E]): The input wrapped in a Result.

        Returns:
            Result[U, E]: The transformed output.
        """
        pass

    def __str__(self) -> str:
        return f"{self.task_name}(ID={self.task_id})"

    def __repr__(self) -> str:
        return self.__str__()

task_name property

Returns a human-readable task name.

__call__(input_result)

Executes the task with retry logic.

Parameters:

Name Type Description Default
input_result Result[T, E]

The input wrapped in a Result.

 required

Returns:

Type Description
Result[U, E]

Result[U, E]: The result of the task, either Ok or Err.
Source code in neopipe/task.py 
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def __call__(self, input_result: Result[T, E]) -> Result[U, E]:
    """
    Executes the task with retry logic.

    Args:
        input_result (Result[T, E]): The input wrapped in a Result.

    Returns:
        Result[U, E]: The result of the task, either Ok or Err.
    """
    last_exception: Optional[Exception] = None

    for attempt in range(1, self.retries + 1):
        try:
            logger.info(
                f"[{self.task_name}] Attempt {attempt} - Task ID: {self.task_id}"
            )
            result = self.execute(input_result)

            if result.is_ok():
                logger.info(f"[{self.task_name}] Success on attempt {attempt}")
                return result
            else:
                logger.error(f"[{self.task_name}] Returned Err: {result.err()}")
                return result

        except Exception as e:
            last_exception = e
            logger.exception(f"[{self.task_name}] Exception on attempt {attempt}")
            time.sleep(2 ** (attempt - 1))  # Exponential backoff

    return Err(
        f"[{self.task_name}] failed after {self.retries} retries and raised Error: {last_exception} with Exception type: {last_exception.__class__.__name__}."
    )

execute(input_result) abstractmethod

Override this method in subclasses or function wrappers.

Parameters:

Name Type Description Default
input_result Result[T, E]

The input wrapped in a Result.

 required

Returns:

Type Description
Result[U, E]

Result[U, E]: The transformed output.
Source code in neopipe/task.py 
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@abstractmethod
def execute(self, input_result: Result[T, E]) -> Result[U, E]:
    """
    Override this method in subclasses or function wrappers.

    Args:
        input_result (Result[T, E]): The input wrapped in a Result.

    Returns:
        Result[U, E]: The transformed output.
    """
    pass

ClassAsyncTask

Bases: BaseAsyncTask[T, E], ABC

Extend this class to define custom async tasks that operate on Result[T, E].

Example

class MultiplyTask(ClassAsyncTask[int, str]): def init(self, factor: int): super().init() self.factor = factor

async def execute(self, input_result: Result[int, str]) -> Result[int, str]:
    if input_result.is_ok():
        return Ok(input_result.unwrap() * self.factor)
    return input_result
Source code in neopipe/task.py 
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class ClassAsyncTask(BaseAsyncTask[T, E], ABC):
    """
    Extend this class to define custom async tasks that operate on Result[T, E].

    Example:
        class MultiplyTask(ClassAsyncTask[int, str]):
            def __init__(self, factor: int):
                super().__init__()
                self.factor = factor

            async def execute(self, input_result: Result[int, str]) -> Result[int, str]:
                if input_result.is_ok():
                    return Ok(input_result.unwrap() * self.factor)
                return input_result
    """

    def __init__(self, retries: int = 1):
        super().__init__(retries)

ClassSyncTask

Bases: BaseSyncTask[T, E], ABC

Extend this class to create stateful or configurable sync tasks.

You must override the execute(self, input_result: Result[T, E]) method.

Example

class MultiplyTask(ClassSyncTask[int, str]): def init(self, factor: int): super().init() self.factor = factor

def execute(self, input_result: Result[int, str]) -> Result[int, str]:
    if input_result.is_ok():
        return Ok(input_result.unwrap() * self.factor)
    return input_result
Source code in neopipe/task.py 
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class ClassSyncTask(BaseSyncTask[T, E], ABC):
    """
    Extend this class to create stateful or configurable sync tasks.

    You must override the `execute(self, input_result: Result[T, E])` method.

    Example:
        class MultiplyTask(ClassSyncTask[int, str]):
            def __init__(self, factor: int):
                super().__init__()
                self.factor = factor

            def execute(self, input_result: Result[int, str]) -> Result[int, str]:
                if input_result.is_ok():
                    return Ok(input_result.unwrap() * self.factor)
                return input_result
    """

    def __init__(self, retries: int = 1):
        super().__init__(retries)

FunctionAsyncTask

Bases: BaseAsyncTask[T, E]

Wraps an async function that takes a Result[T, E] and returns a Result[U, E].

Source code in neopipe/task.py 
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class FunctionAsyncTask(BaseAsyncTask[T, E]):
    """
    Wraps an async function that takes a Result[T, E] and returns a Result[U, E].
    """

    def __init__(
        self, func: Callable[[Result[T, E]], Awaitable[Result[U, E]]], retries: int = 1
    ):
        super().__init__(retries)
        self.func = func

    @property
    def task_name(self) -> str:
        return self.func.__name__

    async def execute(self, input_result: Result[T, E]) -> Result[U, E]:
        return await self.func(input_result)

    @classmethod
    def decorator(cls, retries: int = 1):
        """
        A decorator for turning an async function into a FunctionAsyncTask.

        Example:
            @FunctionAsyncTask.decorator(retries=2)
            async def fetch(result: Result[str, str]) -> Result[str, str]:
                ...

        Returns:
            FunctionAsyncTask[T, E]
        """

        def wrapper(func: Callable[[Result[T, E]], Awaitable[Result[U, E]]]) -> Self:
            task = cls(func, retries)

            @wraps(func)
            async def wrapped(input_result: Result[T, E]) -> Result[U, E]:
                return await task(input_result)

            wrapped.task = task
            return task

        return wrapper

    def __str__(self):
        return f"FunctionAsyncTask({self.task_name}, ID={self.task_id})"

decorator(retries=1) classmethod

A decorator for turning an async function into a FunctionAsyncTask.

Example

@FunctionAsyncTask.decorator(retries=2) async def fetch(result: Result[str, str]) -> Result[str, str]: ...

Returns:

Type Description

FunctionAsyncTask[T, E]
Source code in neopipe/task.py 
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@classmethod
def decorator(cls, retries: int = 1):
    """
    A decorator for turning an async function into a FunctionAsyncTask.

    Example:
        @FunctionAsyncTask.decorator(retries=2)
        async def fetch(result: Result[str, str]) -> Result[str, str]:
            ...

    Returns:
        FunctionAsyncTask[T, E]
    """

    def wrapper(func: Callable[[Result[T, E]], Awaitable[Result[U, E]]]) -> Self:
        task = cls(func, retries)

        @wraps(func)
        async def wrapped(input_result: Result[T, E]) -> Result[U, E]:
            return await task(input_result)

        wrapped.task = task
        return task

    return wrapper

FunctionSyncTask

Bases: BaseSyncTask[T, E]

Wraps a function that takes a Result[T, E] and returns a Result[U, E].

Can be used as a decorator with automatic retry and logging support.

Source code in neopipe/task.py 
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class FunctionSyncTask(BaseSyncTask[T, E]):
    """
    Wraps a function that takes a Result[T, E] and returns a Result[U, E].

    Can be used as a decorator with automatic retry and logging support.
    """

    def __init__(self, func: Callable[[Result[T, E]], Result[U, E]], retries: int = 1):
        super().__init__(retries)
        self.func = func

    @property
    def task_name(self) -> str:
        return self.func.__name__

    def execute(self, input_result: Result[T, E]) -> Result[U, E]:
        return self.func(input_result)

    @classmethod
    def decorator(cls, retries: int = 1):
        """
        A decorator for converting a function into a retryable FunctionSyncTask.

        Example:
            @FunctionSyncTask.decorator(retries=2)
            def process(result: Result[int, str]) -> Result[int, str]:
                ...

        Args:
            retries (int): Number of retry attempts.

        Returns:
            Callable: A decorator that wraps the function in a FunctionSyncTask.
        """

        def wrapper(func: Callable[[Result[T, E]], Result[U, E]]) -> Self:
            task = cls(func, retries)

            @wraps(func)
            def wrapped(input_result: Result[T, E]) -> Result[U, E]:
                return task(input_result)

            wrapped.task = task  # Optional: attach task instance
            return task

        return wrapper

    def __str__(self):
        return f"FunctionSyncTask({self.task_name}, ID={self.task_id})"

decorator(retries=1) classmethod

A decorator for converting a function into a retryable FunctionSyncTask.

Example

@FunctionSyncTask.decorator(retries=2) def process(result: Result[int, str]) -> Result[int, str]: ...

Parameters:

Name Type Description Default
retries int

Number of retry attempts.

 1

Returns:

Name Type Description
Callable

A decorator that wraps the function in a FunctionSyncTask.
Source code in neopipe/task.py 
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@classmethod
def decorator(cls, retries: int = 1):
    """
    A decorator for converting a function into a retryable FunctionSyncTask.

    Example:
        @FunctionSyncTask.decorator(retries=2)
        def process(result: Result[int, str]) -> Result[int, str]:
            ...

    Args:
        retries (int): Number of retry attempts.

    Returns:
        Callable: A decorator that wraps the function in a FunctionSyncTask.
    """

    def wrapper(func: Callable[[Result[T, E]], Result[U, E]]) -> Self:
        task = cls(func, retries)

        @wraps(func)
        def wrapped(input_result: Result[T, E]) -> Result[U, E]:
            return task(input_result)

        wrapped.task = task  # Optional: attach task instance
        return task

    return wrapper