|
| 1 | +from __future__ import absolute_import |
| 2 | +from bisect import bisect_left |
| 3 | + |
| 4 | +from ._base import Trie as ABCTrie |
| 5 | + |
| 6 | +class Trie(ABCTrie): |
| 7 | + def __init__(self, data): |
| 8 | + if not all(isinstance(x, unicode) for x in data.keys()): |
| 9 | + raise TypeError(u"All keys must be strings") |
| 10 | + |
| 11 | + self._data = data |
| 12 | + self._keys = sorted(data.keys()) |
| 13 | + self._cachestr = u"" |
| 14 | + self._cachepoints = (0, len(data)) |
| 15 | + __init__.func_annotations = {} |
| 16 | + |
| 17 | + def __contains__(self, key): |
| 18 | + return key in self._data |
| 19 | + __contains__.func_annotations = {} |
| 20 | + |
| 21 | + def __len__(self): |
| 22 | + return len(self._data) |
| 23 | + __len__.func_annotations = {} |
| 24 | + |
| 25 | + def __iter__(self): |
| 26 | + return iter(self._data) |
| 27 | + __iter__.func_annotations = {} |
| 28 | + |
| 29 | + def __getitem__(self, key): |
| 30 | + return self._data[key] |
| 31 | + __getitem__.func_annotations = {} |
| 32 | + |
| 33 | + def keys(self, prefix=None): |
| 34 | + if prefix is None or prefix == u"" or not self._keys: |
| 35 | + return set(self._keys) |
| 36 | + |
| 37 | + if prefix.startswith(self._cachestr): |
| 38 | + lo, hi = self._cachepoints |
| 39 | + start = i = bisect_left(self._keys, prefix, lo, hi) |
| 40 | + else: |
| 41 | + start = i = bisect_left(self._keys, prefix) |
| 42 | + |
| 43 | + keys = set() |
| 44 | + if start == len(self._keys): |
| 45 | + return keys |
| 46 | + |
| 47 | + while self._keys[i].startswith(prefix): |
| 48 | + keys.add(self._keys[i]) |
| 49 | + i += 1 |
| 50 | + |
| 51 | + self._cachestr = prefix |
| 52 | + self._cachepoints = (start, i) |
| 53 | + |
| 54 | + return keys |
| 55 | + keys.func_annotations = {} |
| 56 | + |
| 57 | + def has_keys_with_prefix(self, prefix): |
| 58 | + if prefix in self._data: |
| 59 | + return True |
| 60 | + |
| 61 | + if prefix.startswith(self._cachestr): |
| 62 | + lo, hi = self._cachepoints |
| 63 | + i = bisect_left(self._keys, prefix, lo, hi) |
| 64 | + else: |
| 65 | + i = bisect_left(self._keys, prefix) |
| 66 | + |
| 67 | + if i == len(self._keys): |
| 68 | + return False |
| 69 | + |
| 70 | + return self._keys[i].startswith(prefix) |
| 71 | + has_keys_with_prefix.func_annotations = {} |
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