# SPDX-License-Identifier: MIT
# Copyright (C) 2023 Max Bachmann
from __future__ import annotations
from array import array
from collections.abc import Hashable, Sequence
def conv_sequence(s: Sequence[Hashable]) -> Sequence[Hashable]:
if isinstance(s, str):
return [ord(x) for x in s]
if isinstance(s, bytes):
return s
if isinstance(s, array):
if s.typecode in ("u", "w"):
return [ord(x) for x in s]
return s
if s is None:
return s
res = []
for elem in s:
if isinstance(elem, str) and len(elem) == 1:
res.append(ord(elem))
elif isinstance(elem, int) and elem == -1:
res.append(-1)
else:
res.append(hash(elem))
return res
def conv_sequences(s1: Sequence[Hashable], s2: Sequence[Hashable]) -> tuple[Sequence[Hashable], Sequence[Hashable]]:
if isinstance(s1, str) and isinstance(s2, str):
return s1, s2
if isinstance(s1, bytes) and isinstance(s2, bytes):
return s1, s2
return conv_sequence(s1), conv_sequence(s2)
def common_prefix(s1: Sequence[Hashable], s2: Sequence[Hashable]) -> int:
prefix_len = 0
for ch1, ch2 in zip(s1, s2):
if ch1 != ch2:
break
prefix_len += 1
return prefix_len
def common_suffix(s1: Sequence[Hashable], s2: Sequence[Hashable]) -> int:
suffix_len = 0
for ch1, ch2 in zip(reversed(s1), reversed(s2)):
if ch1 != ch2:
break
suffix_len += 1
return suffix_len
def common_affix(s1: Sequence[Hashable], s2: Sequence[Hashable]) -> tuple[int, int]:
prefix_len = common_prefix(s1, s2)
suffix_len = common_suffix(s1[prefix_len:], s2[prefix_len:])
return (prefix_len, suffix_len)