Errors

Every failure raises a subclass of usearch.Error, itself a RuntimeError, and each carries the status the C ABI reported as its status attribute, a usearch.Status member:

try:
    index.on(pool).search(queries, 10, arena, progress=lambda completed, total: completed < 100)
except usearch.CancelledError:
    ...  # The handler stopped the call, which published nothing
except usearch.Error as error:
    print(error.status)  # Status.SHAPE_MISMATCH, Status.READ_ONLY, Status.DEVICE, ...

usearch.Status is an enum.IntEnum valued as usearch_status_t. SUCCESS and DEFERRED raise nothing, and every other member has its own class, which also derives the built-in naming the same fault where one exists:

• OUT_OF_MEMORY → OutOfMemoryError, a MemoryError
• SHAPE_MISMATCH → ShapeMismatchError, a ValueError
• UNSUPPORTED_LAYOUT → UnsupportedLayoutError, a ValueError
• UNKNOWN_KIND → UnknownKindError, a ValueError
• READ_ONLY → ReadOnlyError
• IO → InputOutputError, an OSError
• DEVICE → DeviceError
• MALFORMED → MalformedError, a ValueError
• INTERNAL → InternalError
• OVERFLOW → CapacityOverflowError, an OverflowError
• UNINITIALIZED → UninitializedError
• CONFIG_MISMATCH → ConfigMismatchError, a ValueError
• CONTENDED → ContendedError
• CANCELLED → CancelledError
• UNSUPPORTED → UnsupportedError, a NotImplementedError
• INVALID_ARGUMENT → InvalidArgumentError, a ValueError

So except ValueError catches a ShapeMismatchError, except OSError an InputOutputError, and except MemoryError an OutOfMemoryError. A failure the binding catches before the boundary raises the class the engine would have raised for the same fault. Arguments the binding refuses raise at the call, while the engine’s refusals of a deferred call raise at await or wait(), as many times as they are asked.