Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.9/dist-packages/pyparsing/util.py: 53%

1# util.py

2import contextlib

3from functools import lru_cache, wraps

4import inspect

5import itertools

6import types

7from typing import Callable, Union, Iterable, TypeVar, cast

8import warnings

10_bslash = chr(92)

11C = TypeVar("C", bound=Callable)

14class __config_flags:

15 """Internal class for defining compatibility and debugging flags"""

17 _all_names: list[str] = []

18 _fixed_names: list[str] = []

19 _type_desc = "configuration"

21 @classmethod

22 def _set(cls, dname, value):

23 if dname in cls._fixed_names:

24 warnings.warn(

25 f"{cls.__name__}.{dname} {cls._type_desc} is {str(getattr(cls, dname)).upper()}"

26 f" and cannot be overridden",

27 stacklevel=3,

28 )

29 return

30 if dname in cls._all_names:

31 setattr(cls, dname, value)

32 else:

33 raise ValueError(f"no such {cls._type_desc} {dname!r}")

35 enable = classmethod(lambda cls, name: cls._set(name, True))

36 disable = classmethod(lambda cls, name: cls._set(name, False))

39@lru_cache(maxsize=128)

40def col(loc: int, strg: str) -> int:

41 """

42 Returns current column within a string, counting newlines as line separators.

43 The first column is number 1.

45 Note: the default parsing behavior is to expand tabs in the input string

46 before starting the parsing process. See

47 :class:`ParserElement.parse_string` for more

48 information on parsing strings containing ``<TAB>`` s, and suggested

49 methods to maintain a consistent view of the parsed string, the parse

50 location, and line and column positions within the parsed string.

51 """

52 s = strg

53 return 1 if 0 < loc < len(s) and s[loc - 1] == "\n" else loc - s.rfind("\n", 0, loc)

56@lru_cache(maxsize=128)

57def lineno(loc: int, strg: str) -> int:

58 """Returns current line number within a string, counting newlines as line separators.

59 The first line is number 1.

61 Note - the default parsing behavior is to expand tabs in the input string

62 before starting the parsing process. See :class:`ParserElement.parse_string`

63 for more information on parsing strings containing ``<TAB>`` s, and

64 suggested methods to maintain a consistent view of the parsed string, the

65 parse location, and line and column positions within the parsed string.

66 """

67 return strg.count("\n", 0, loc) + 1

70@lru_cache(maxsize=128)

71def line(loc: int, strg: str) -> str:

72 """

73 Returns the line of text containing loc within a string, counting newlines as line separators.

74 """

75 last_cr = strg.rfind("\n", 0, loc)

76 next_cr = strg.find("\n", loc)

77 return strg[last_cr + 1 : next_cr] if next_cr >= 0 else strg[last_cr + 1 :]

80class _UnboundedCache:

81 def __init__(self):

82 cache = {}

83 cache_get = cache.get

84 self.not_in_cache = not_in_cache = object()

86 def get(_, key):

87 return cache_get(key, not_in_cache)

89 def set_(_, key, value):

90 cache[key] = value

92 def clear(_):

93 cache.clear()

95 self.size = None

96 self.get = types.MethodType(get, self)

97 self.set = types.MethodType(set_, self)

98 self.clear = types.MethodType(clear, self)

100

101class _FifoCache:

102 def __init__(self, size):

103 cache = {}

104 self.size = size

105 self.not_in_cache = not_in_cache = object()

106 cache_get = cache.get

107 cache_pop = cache.pop

108

109 def get(_, key):

110 return cache_get(key, not_in_cache)

111

112 def set_(_, key, value):

113 cache[key] = value

114 while len(cache) > size:

115 # pop oldest element in cache by getting the first key

116 cache_pop(next(iter(cache)))

117

118 def clear(_):

119 cache.clear()

120

121 self.get = types.MethodType(get, self)

122 self.set = types.MethodType(set_, self)

123 self.clear = types.MethodType(clear, self)

124

125

126class LRUMemo:

127 """

128 A memoizing mapping that retains `capacity` deleted items

129

130 The memo tracks retained items by their access order; once `capacity` items

131 are retained, the least recently used item is discarded.

132 """

133

134 def __init__(self, capacity):

135 self._capacity = capacity

136 self._active = {}

137 self._memory = {}

138

139 def __getitem__(self, key):

140 try:

141 return self._active[key]

142 except KeyError:

143 self._memory[key] = self._memory.pop(key)

144 return self._memory[key]

145

146 def __setitem__(self, key, value):

147 self._memory.pop(key, None)

148 self._active[key] = value

149

150 def __delitem__(self, key):

151 try:

152 value = self._active.pop(key)

153 except KeyError:

154 pass

155 else:

156 oldest_keys = list(self._memory)[: -(self._capacity + 1)]

157 for key_to_delete in oldest_keys:

158 self._memory.pop(key_to_delete)

159 self._memory[key] = value

160

161 def clear(self):

162 self._active.clear()

163 self._memory.clear()

164

165

166class UnboundedMemo(dict):

167 """

168 A memoizing mapping that retains all deleted items

169 """

170

171 def __delitem__(self, key):

172 pass

173

174

175def _escape_regex_range_chars(s: str) -> str:

176 # escape these chars: ^-[]

177 for c in r"\^-[]":

178 s = s.replace(c, _bslash + c)

179 s = s.replace("\n", r"\n")

180 s = s.replace("\t", r"\t")

181 return str(s)

182

183

184class _GroupConsecutive:

185 """

186 Used as a callable `key` for itertools.groupby to group

187 characters that are consecutive:

188 itertools.groupby("abcdejkmpqrs", key=IsConsecutive())

189 yields:

190 (0, iter(['a', 'b', 'c', 'd', 'e']))

191 (1, iter(['j', 'k']))

192 (2, iter(['m']))

193 (3, iter(['p', 'q', 'r', 's']))

194 """

195

196 def __init__(self):

197 self.prev = 0

198 self.counter = itertools.count()

199 self.value = -1

200

201 def __call__(self, char: str) -> int:

202 c_int = ord(char)

203 self.prev, prev = c_int, self.prev

204 if c_int - prev > 1:

205 self.value = next(self.counter)

206 return self.value

207

208

209def _collapse_string_to_ranges(

210 s: Union[str, Iterable[str]], re_escape: bool = True

211) -> str:

212 r"""

213 Take a string or list of single-character strings, and return

214 a string of the consecutive characters in that string collapsed

215 into groups, as might be used in a regular expression '[a-z]'

216 character set:

217 'a' -> 'a' -> '[a]'

218 'bc' -> 'bc' -> '[bc]'

219 'defgh' -> 'd-h' -> '[d-h]'

220 'fdgeh' -> 'd-h' -> '[d-h]'

221 'jklnpqrtu' -> 'j-lnp-rtu' -> '[j-lnp-rtu]'

222 Duplicates get collapsed out:

223 'aaa' -> 'a' -> '[a]'

224 'bcbccb' -> 'bc' -> '[bc]'

225 'defghhgf' -> 'd-h' -> '[d-h]'

226 'jklnpqrjjjtu' -> 'j-lnp-rtu' -> '[j-lnp-rtu]'

227 Spaces are preserved:

228 'ab c' -> ' a-c' -> '[ a-c]'

229 Characters that are significant when defining regex ranges

230 get escaped:

231 'acde[]-' -> r'\-\[\]ac-e' -> r'[\-\[\]ac-e]'

232 """

233

234 # Developer notes:

235 # - Do not optimize this code assuming that the given input string

236 # or internal lists will be short (such as in loading generators into

237 # lists to make it easier to find the last element); this method is also

238 # used to generate regex ranges for character sets in the pyparsing.unicode

239 # classes, and these can be _very_ long lists of strings

240

241 def escape_re_range_char(c: str) -> str:

242 return "\\" + c if c in r"\^-][" else c

243

244 def no_escape_re_range_char(c: str) -> str:

245 return c

246

247 if not re_escape:

248 escape_re_range_char = no_escape_re_range_char

249

250 ret = []

251

252 # reduce input string to remove duplicates, and put in sorted order

253 s_chars: list[str] = sorted(set(s))

254

255 if len(s_chars) > 2:

256 # find groups of characters that are consecutive (can be collapsed

257 # down to "<first>-<last>")

258 for _, chars in itertools.groupby(s_chars, key=_GroupConsecutive()):

259 # _ is unimportant, is just used to identify groups

260 # chars is an iterator of one or more consecutive characters

261 # that comprise the current group

262 first = last = next(chars)

263 with contextlib.suppress(ValueError):

264 *_, last = chars

265

266 if first == last:

267 # there was only a single char in this group

268 ret.append(escape_re_range_char(first))

269

270 elif last == chr(ord(first) + 1):

271 # there were only 2 characters in this group

272 # 'a','b' -> 'ab'

273 ret.append(f"{escape_re_range_char(first)}{escape_re_range_char(last)}")

274

275 else:

276 # there were > 2 characters in this group, make into a range

277 # 'c','d','e' -> 'c-e'

278 ret.append(

279 f"{escape_re_range_char(first)}-{escape_re_range_char(last)}"

280 )

281 else:

282 # only 1 or 2 chars were given to form into groups

283 # 'a' -> ['a']

284 # 'bc' -> ['b', 'c']

285 # 'dg' -> ['d', 'g']

286 # no need to list them with "-", just return as a list

287 # (after escaping)

288 ret = [escape_re_range_char(c) for c in s_chars]

289

290 return "".join(ret)

291

292

293def _flatten(ll: Iterable) -> list:

294 ret = []

295 to_visit = [*ll]

296 while to_visit:

297 i = to_visit.pop(0)

298 if isinstance(i, Iterable) and not isinstance(i, str):

299 to_visit[:0] = i

300 else:

301 ret.append(i)

302 return ret

303

304

305def make_compressed_re(

306 word_list: Iterable[str], max_level: int = 2, _level: int = 1

307) -> str:

308 """

309 Create a regular expression string from a list of words, collapsing by common

310 prefixes and optional suffixes.

311

312 Calls itself recursively to build nested sublists for each group of suffixes

313 that have a shared prefix.

314 """

315

316 def get_suffixes_from_common_prefixes(namelist: list[str]):

317 if len(namelist) > 1:

318 for prefix, suffixes in itertools.groupby(namelist, key=lambda s: s[:1]):

319 yield prefix, sorted([s[1:] for s in suffixes], key=len, reverse=True)

320 else:

321 yield namelist[0][0], [namelist[0][1:]]

322

323 if max_level == 0:

324 return "|".join(sorted(word_list, key=len, reverse=True))

325

326 ret = []

327 sep = ""

328 for initial, suffixes in get_suffixes_from_common_prefixes(sorted(word_list)):

329 ret.append(sep)

330 sep = "|"

331

332 trailing = ""

333 if "" in suffixes:

334 trailing = "?"

335 suffixes.remove("")

336

337 if len(suffixes) > 1:

338 if all(len(s) == 1 for s in suffixes):

339 ret.append(f"{initial}[{''.join(suffixes)}]{trailing}")

340 else:

341 if _level < max_level:

342 suffix_re = make_compressed_re(

343 sorted(suffixes), max_level, _level + 1

344 )

345 ret.append(f"{initial}({suffix_re}){trailing}")

346 else:

347 suffixes.sort(key=len, reverse=True)

348 ret.append(f"{initial}({'|'.join(suffixes)}){trailing}")

349 else:

350 if suffixes:

351 suffix = suffixes[0]

352 if len(suffix) > 1 and trailing:

353 ret.append(f"{initial}({suffix}){trailing}")

354 else:

355 ret.append(f"{initial}{suffix}{trailing}")

356 else:

357 ret.append(initial)

358 return "".join(ret)

359

360

361def replaced_by_pep8(compat_name: str, fn: C) -> C:

362 # In a future version, uncomment the code in the internal _inner() functions

363 # to begin emitting DeprecationWarnings.

364

365 # Unwrap staticmethod/classmethod

366 fn = getattr(fn, "__func__", fn)

367

368 # (Presence of 'self' arg in signature is used by explain_exception() methods, so we take

369 # some extra steps to add it if present in decorated function.)

370 if ["self"] == list(inspect.signature(fn).parameters)[:1]:

371

372 @wraps(fn)

373 def _inner(self, *args, **kwargs):

374 # warnings.warn(

375 # f"Deprecated - use {fn.__name__}", DeprecationWarning, stacklevel=2

376 # )

377 return fn(self, *args, **kwargs)

378

379 else:

380

381 @wraps(fn)

382 def _inner(*args, **kwargs):

383 # warnings.warn(

384 # f"Deprecated - use {fn.__name__}", DeprecationWarning, stacklevel=2

385 # )

386 return fn(*args, **kwargs)

387

388 _inner.__doc__ = f"""Deprecated - use :class:`{fn.__name__}`"""

389 _inner.__name__ = compat_name

390 _inner.__annotations__ = fn.__annotations__

391 if isinstance(fn, types.FunctionType):

392 _inner.__kwdefaults__ = fn.__kwdefaults__ # type: ignore [attr-defined]

393 elif isinstance(fn, type) and hasattr(fn, "__init__"):

394 _inner.__kwdefaults__ = fn.__init__.__kwdefaults__ # type: ignore [misc,attr-defined]

395 else:

396 _inner.__kwdefaults__ = None # type: ignore [attr-defined]

397 _inner.__qualname__ = fn.__qualname__

398 return cast(C, _inner)