omnipy.util.range_lookup

Fast membership lookup for collections of non-negative integer ranges.

This module compacts a set of range objects into a bitarray-backed lookup table for repeated containment checks.

CLASS	DESCRIPTION
RangeLookup	Provide constant-time containment checks for integer ranges.

RangeLookup

Provide constant-time containment checks for integer ranges.

PARAMETER	DESCRIPTION
ranges	Ranges to encode into the lookup table. TYPE: Iterable[range]

RAISES	DESCRIPTION
ValueError	If any range contains negative values.

METHOD	DESCRIPTION
__init__

Source code in src/omnipy/util/range_lookup.py

class RangeLookup:
    """Provide constant-time containment checks for integer ranges.

    Args:
        ranges: Ranges to encode into the lookup table.

    Raises:
        ValueError: If any range contains negative values.
    """
    def __init__(self, ranges: Iterable[range]):
        largest_range_stop = max((r.stop for r in ranges), default=0)
        if largest_range_stop >= 0:
            self._range_array = bitarray(largest_range_stop)
        for range_ in ranges:
            if range_.start < 0 or range_.stop < 0:
                raise ValueError(f'Negative numbers are not supported for ranges: {range_}')
            self._range_array[range_] = 1

    def __contains__(self, number: int) -> bool:
        if number < 0:
            raise ValueError(f'Negative numbers are not supported for lookup: {number}')
        if number >= len(self._range_array):
            return False
        return bool(self._range_array[number])

__init__

__init__(ranges: Iterable[range])

Source code in src/omnipy/util/range_lookup.py

def __init__(self, ranges: Iterable[range]):
    largest_range_stop = max((r.stop for r in ranges), default=0)
    if largest_range_stop >= 0:
        self._range_array = bitarray(largest_range_stop)
    for range_ in ranges:
        if range_.start < 0 or range_.stop < 0:
            raise ValueError(f'Negative numbers are not supported for ranges: {range_}')
        self._range_array[range_] = 1