# Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/idna/intranges.py: 20%

## 30 statements

, created at 2023-12-08 06:51 +0000

1"""

2Given a list of integers, made up of (hopefully) a small number of long runs

3of consecutive integers, compute a representation of the form

4((start1, end1), (start2, end2) ...). Then answer the question "was x present

5in the original list?" in time O(log(# runs)).

6"""

8import bisect

9from typing import List, Tuple

11def intranges_from_list(list_: List[int]) -> Tuple[int, ...]:

12 """Represent a list of integers as a sequence of ranges:

13 ((start_0, end_0), (start_1, end_1), ...), such that the original

14 integers are exactly those x such that start_i <= x < end_i for some i.

16 Ranges are encoded as single integers (start << 32 | end), not as tuples.

17 """

19 sorted_list = sorted(list_)

20 ranges = []

21 last_write = -1

22 for i in range(len(sorted_list)):

23 if i+1 < len(sorted_list):

24 if sorted_list[i] == sorted_list[i+1]-1:

25 continue

26 current_range = sorted_list[last_write+1:i+1]

27 ranges.append(_encode_range(current_range[0], current_range[-1] + 1))

28 last_write = i

30 return tuple(ranges)

32def _encode_range(start: int, end: int) -> int:

33 return (start << 32) | end

35def _decode_range(r: int) -> Tuple[int, int]:

36 return (r >> 32), (r & ((1 << 32) - 1))

39def intranges_contain(int_: int, ranges: Tuple[int, ...]) -> bool:

40 """Determine if `int_` falls into one of the ranges in `ranges`."""

41 tuple_ = _encode_range(int_, 0)

42 pos = bisect.bisect_left(ranges, tuple_)

43 # we could be immediately ahead of a tuple (start, end)

44 # with start < int_ <= end

45 if pos > 0:

46 left, right = _decode_range(ranges[pos-1])

47 if left <= int_ < right:

48 return True

49 # or we could be immediately behind a tuple (int_, end)

50 if pos < len(ranges):

51 left, _ = _decode_range(ranges[pos])

52 if left == int_:

53 return True

54 return False