"""Create fallback_executor
Generated by Phi-Octopus Eden
2025-11-06 12:01:50.117110
"""

```python
from typing import Any, Callable, Dict, Optional


class FallbackExecutor:
    """
    A class for executing functions with fallback mechanisms in case of errors.
    
    Attributes:
        primary_exec: The primary function to be executed.
        fallback_execs: A dictionary mapping exceptions to their respective fallback functions.
    """

    def __init__(self, primary_exec: Callable[..., Any], fallback_execs: Dict[type[Exception], Callable[..., Any]]):
        self.primary_exec = primary_exec
        self.fallback_execs = fallback_execs

    def execute(self, *args: Any, **kwargs: Any) -> Any:
        """
        Execute the primary function. If an error occurs, attempt to use a fallback function.
        
        Args:
            *args: Positional arguments passed to the primary function.
            **kwargs: Keyword arguments passed to the primary function.

        Returns:
            The result of the executed function or the fallback function if applicable.
        """
        try:
            return self.primary_exec(*args, **kwargs)
        except Exception as e:
            for exception_type, fallback in self.fallback_execs.items():
                if isinstance(e, exception_type):
                    print(f"Primary execution failed with {type(e).__name__}. Fallback executing...")
                    return fallback()
            raise

# Example usage
def primary_function(x: int) -> int:
    """
    A function that may fail due to invalid input.
    
    Args:
        x: An integer value.

    Returns:
        The square of the input if successful.
    """
    try:
        return x ** 2
    except TypeError as e:
        raise ValueError("Input must be an integer") from e

def fallback_function() -> int:
    """
    A fallback function to handle errors when primary_function fails.
    
    Returns:
        A default value of -1 in case of error.
    """
    print("Executing fallback function.")
    return -1

# Creating a FallbackExecutor instance
executor = FallbackExecutor(
    primary_exec=primary_function,
    fallback_execs={ValueError: fallback_function}
)

# Example calls
print(executor.execute(2))  # Should work fine, returns 4
print(executor.execute('a'))  # Should trigger fallback, prints "Executing fallback function." and returns -1
```

This code defines a `FallbackExecutor` class that can be used to wrap functions with error handling. The primary function is executed first, and if it raises an exception, the appropriate fallback function is called based on the exception type.