initial commit

Lib/site-packages/pip/_vendor/pyparsing/util.py

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+# util.py
+import inspect
+import warnings
+import types
+import collections
+import itertools
+from functools import lru_cache, wraps
+from typing import Callable, List, Union, Iterable, TypeVar, cast
+
+_bslash = chr(92)
+C = TypeVar("C", bound=Callable)
+
+
+class __config_flags:
+    """Internal class for defining compatibility and debugging flags"""
+
+    _all_names: List[str] = []
+    _fixed_names: List[str] = []
+    _type_desc = "configuration"
+
+    @classmethod
+    def _set(cls, dname, value):
+        if dname in cls._fixed_names:
+            warnings.warn(
+                f"{cls.__name__}.{dname} {cls._type_desc} is {str(getattr(cls, dname)).upper()}"
+                f" and cannot be overridden",
+                stacklevel=3,
+            )
+            return
+        if dname in cls._all_names:
+            setattr(cls, dname, value)
+        else:
+            raise ValueError(f"no such {cls._type_desc} {dname!r}")
+
+    enable = classmethod(lambda cls, name: cls._set(name, True))
+    disable = classmethod(lambda cls, name: cls._set(name, False))
+
+
+@lru_cache(maxsize=128)
+def col(loc: int, strg: str) -> int:
+    """
+    Returns current column within a string, counting newlines as line separators.
+    The first column is number 1.
+
+    Note: the default parsing behavior is to expand tabs in the input string
+    before starting the parsing process.  See
+    :class:`ParserElement.parse_string` for more
+    information on parsing strings containing ``<TAB>`` s, and suggested
+    methods to maintain a consistent view of the parsed string, the parse
+    location, and line and column positions within the parsed string.
+    """
+    s = strg
+    return 1 if 0 < loc < len(s) and s[loc - 1] == "\n" else loc - s.rfind("\n", 0, loc)
+
+
+@lru_cache(maxsize=128)
+def lineno(loc: int, strg: str) -> int:
+    """Returns current line number within a string, counting newlines as line separators.
+    The first line is number 1.
+
+    Note - the default parsing behavior is to expand tabs in the input string
+    before starting the parsing process.  See :class:`ParserElement.parse_string`
+    for more information on parsing strings containing ``<TAB>`` s, and
+    suggested methods to maintain a consistent view of the parsed string, the
+    parse location, and line and column positions within the parsed string.
+    """
+    return strg.count("\n", 0, loc) + 1
+
+
+@lru_cache(maxsize=128)
+def line(loc: int, strg: str) -> str:
+    """
+    Returns the line of text containing loc within a string, counting newlines as line separators.
+    """
+    last_cr = strg.rfind("\n", 0, loc)
+    next_cr = strg.find("\n", loc)
+    return strg[last_cr + 1 : next_cr] if next_cr >= 0 else strg[last_cr + 1 :]
+
+
+class _UnboundedCache:
+    def __init__(self):
+        cache = {}
+        cache_get = cache.get
+        self.not_in_cache = not_in_cache = object()
+
+        def get(_, key):
+            return cache_get(key, not_in_cache)
+
+        def set_(_, key, value):
+            cache[key] = value
+
+        def clear(_):
+            cache.clear()
+
+        self.size = None
+        self.get = types.MethodType(get, self)
+        self.set = types.MethodType(set_, self)
+        self.clear = types.MethodType(clear, self)
+
+
+class _FifoCache:
+    def __init__(self, size):
+        self.not_in_cache = not_in_cache = object()
+        cache = {}
+        keyring = [object()] * size
+        cache_get = cache.get
+        cache_pop = cache.pop
+        keyiter = itertools.cycle(range(size))
+
+        def get(_, key):
+            return cache_get(key, not_in_cache)
+
+        def set_(_, key, value):
+            cache[key] = value
+            i = next(keyiter)
+            cache_pop(keyring[i], None)
+            keyring[i] = key
+
+        def clear(_):
+            cache.clear()
+            keyring[:] = [object()] * size
+
+        self.size = size
+        self.get = types.MethodType(get, self)
+        self.set = types.MethodType(set_, self)
+        self.clear = types.MethodType(clear, self)
+
+
+class LRUMemo:
+    """
+    A memoizing mapping that retains `capacity` deleted items
+
+    The memo tracks retained items by their access order; once `capacity` items
+    are retained, the least recently used item is discarded.
+    """
+
+    def __init__(self, capacity):
+        self._capacity = capacity
+        self._active = {}
+        self._memory = collections.OrderedDict()
+
+    def __getitem__(self, key):
+        try:
+            return self._active[key]
+        except KeyError:
+            self._memory.move_to_end(key)
+            return self._memory[key]
+
+    def __setitem__(self, key, value):
+        self._memory.pop(key, None)
+        self._active[key] = value
+
+    def __delitem__(self, key):
+        try:
+            value = self._active.pop(key)
+        except KeyError:
+            pass
+        else:
+            while len(self._memory) >= self._capacity:
+                self._memory.popitem(last=False)
+            self._memory[key] = value
+
+    def clear(self):
+        self._active.clear()
+        self._memory.clear()
+
+
+class UnboundedMemo(dict):
+    """
+    A memoizing mapping that retains all deleted items
+    """
+
+    def __delitem__(self, key):
+        pass
+
+
+def _escape_regex_range_chars(s: str) -> str:
+    # escape these chars: ^-[]
+    for c in r"\^-[]":
+        s = s.replace(c, _bslash + c)
+    s = s.replace("\n", r"\n")
+    s = s.replace("\t", r"\t")
+    return str(s)
+
+
+def _collapse_string_to_ranges(
+    s: Union[str, Iterable[str]], re_escape: bool = True
+) -> str:
+    def is_consecutive(c):
+        c_int = ord(c)
+        is_consecutive.prev, prev = c_int, is_consecutive.prev
+        if c_int - prev > 1:
+            is_consecutive.value = next(is_consecutive.counter)
+        return is_consecutive.value
+
+    is_consecutive.prev = 0  # type: ignore [attr-defined]
+    is_consecutive.counter = itertools.count()  # type: ignore [attr-defined]
+    is_consecutive.value = -1  # type: ignore [attr-defined]
+
+    def escape_re_range_char(c):
+        return "\\" + c if c in r"\^-][" else c
+
+    def no_escape_re_range_char(c):
+        return c
+
+    if not re_escape:
+        escape_re_range_char = no_escape_re_range_char
+
+    ret = []
+    s = "".join(sorted(set(s)))
+    if len(s) > 3:
+        for _, chars in itertools.groupby(s, key=is_consecutive):
+            first = last = next(chars)
+            last = collections.deque(
+                itertools.chain(iter([last]), chars), maxlen=1
+            ).pop()
+            if first == last:
+                ret.append(escape_re_range_char(first))
+            else:
+                sep = "" if ord(last) == ord(first) + 1 else "-"
+                ret.append(
+                    f"{escape_re_range_char(first)}{sep}{escape_re_range_char(last)}"
+                )
+    else:
+        ret = [escape_re_range_char(c) for c in s]
+
+    return "".join(ret)
+
+
+def _flatten(ll: list) -> list:
+    ret = []
+    for i in ll:
+        if isinstance(i, list):
+            ret.extend(_flatten(i))
+        else:
+            ret.append(i)
+    return ret
+
+
+def _make_synonym_function(compat_name: str, fn: C) -> C:
+    # In a future version, uncomment the code in the internal _inner() functions
+    # to begin emitting DeprecationWarnings.
+
+    # Unwrap staticmethod/classmethod
+    fn = getattr(fn, "__func__", fn)
+
+    # (Presence of 'self' arg in signature is used by explain_exception() methods, so we take
+    # some extra steps to add it if present in decorated function.)
+    if "self" == list(inspect.signature(fn).parameters)[0]:
+
+        @wraps(fn)
+        def _inner(self, *args, **kwargs):
+            # warnings.warn(
+            #     f"Deprecated - use {fn.__name__}", DeprecationWarning, stacklevel=3
+            # )
+            return fn(self, *args, **kwargs)
+
+    else:
+
+        @wraps(fn)
+        def _inner(*args, **kwargs):
+            # warnings.warn(
+            #     f"Deprecated - use {fn.__name__}", DeprecationWarning, stacklevel=3
+            # )
+            return fn(*args, **kwargs)
+
+    _inner.__doc__ = f"""Deprecated - use :class:`{fn.__name__}`"""
+    _inner.__name__ = compat_name
+    _inner.__annotations__ = fn.__annotations__
+    if isinstance(fn, types.FunctionType):
+        _inner.__kwdefaults__ = fn.__kwdefaults__
+    elif isinstance(fn, type) and hasattr(fn, "__init__"):
+        _inner.__kwdefaults__ = fn.__init__.__kwdefaults__
+    else:
+        _inner.__kwdefaults__ = None
+    _inner.__qualname__ = fn.__qualname__
+    return cast(C, _inner)
+
+
+def replaced_by_pep8(fn: C) -> Callable[[Callable], C]:
+    """
+    Decorator for pre-PEP8 compatibility synonyms, to link them to the new function.
+    """
+    return lambda other: _make_synonym_function(other.__name__, fn)