text: # This file is dual licensed under the terms of the Apache License, Version
  
  # 2.0, and the BSD License. See the LICENSE file in the root of this repository
  
  # for complete details.
  
  from __future__ import absolute_import, division, print_function
  
  
  
  import re
  
  import string
  
  import sys
  
  
  
  from pip._vendor.pyparsing import (  # noqa: N817
  
      Combine,
  
      Literal as L,
  
      Optional,
  
      ParseException,
  
      Regex,
  
      Word,
  
      ZeroOrMore,
  
      originalTextFor,
  
      stringEnd,
  
      stringStart,
  
  )
  
  
  
  from ._typing import TYPE_CHECKING
  
  from .markers import MARKER_EXPR, Marker
  
  from .specifiers import LegacySpecifier, Specifier, SpecifierSet
  
  
  
  if sys.version_info[0] >= 3:
  
      from urllib import parse as urlparse  # pragma: no cover
  
  else:  # pragma: no cover
  
      import urlparse
  
  
  
  
  
  if TYPE_CHECKING:  # pragma: no cover
  
      from typing import List, Optional as TOptional, Set
  
  
  
  
  
  class InvalidRequirement(ValueError):
  
      """
  
      An invalid requirement was found, users should refer to PEP 508.
  
      """
  
  
  
  
  
  ALPHANUM = Word(string.ascii_letters + string.digits)
  
  
  
  LBRACKET = L("[").suppress()
  
  RBRACKET = L("]").suppress()
  
  LPAREN = L("(").suppress()
  
  RPAREN = L(")").suppress()
  
  COMMA = L(",").suppress()
  
  SEMICOLON = L(";").suppress()
  
  AT = L("@").suppress()
  
  
  
  PUNCTUATION = Word("-_.")
  
  IDENTIFIER_END = ALPHANUM | (ZeroOrMore(PUNCTUATION) + ALPHANUM)
  
  IDENTIFIER = Combine(ALPHANUM + ZeroOrMore(IDENTIFIER_END))
  
  
  
  NAME = IDENTIFIER("name")
  
  EXTRA = IDENTIFIER
  
  
  
  URI = Regex(r"[^ ]+")("url")
  
  URL = AT + URI
  
  
  
  EXTRAS_LIST = EXTRA + ZeroOrMore(COMMA + EXTRA)
  
  EXTRAS = (LBRACKET + Optional(EXTRAS_LIST) + RBRACKET)("extras")
  
  
  
  VERSION_PEP440 = Regex(Specifier._regex_str, re.VERBOSE | re.IGNORECASE)
  
  VERSION_LEGACY = Regex(LegacySpecifier._regex_str, re.VERBOSE | re.IGNORECASE)
  
  
  
  VERSION_ONE = VERSION_PEP440 ^ VERSION_LEGACY
  
  VERSION_MANY = Combine(
  
      VERSION_ONE + ZeroOrMore(COMMA + VERSION_ONE), joinString=",", adjacent=False
  
  )("_raw_spec")
  
  _VERSION_SPEC = Optional(((LPAREN + VERSION_MANY + RPAREN) | VERSION_MANY))
  
  _VERSION_SPEC.setParseAction(lambda s, l, t: t._raw_spec or "")
  
  
  
  VERSION_SPEC = originalTextFor(_VERSION_SPEC)("specifier")
  
  VERSION_SPEC.setParseAction(lambda s, l, t: t[1])
  
  
  
  MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
  
  MARKER_EXPR.setParseAction(
  
      lambda s, l, t: Marker(s[t._original_start : t._original_end])
  
  )
  
  MARKER_SEPARATOR = SEMICOLON
  
  MARKER = MARKER_SEPARATOR + MARKER_EXPR
  
  
  
  VERSION_AND_MARKER = VERSION_SPEC + Optional(MARKER)
  
  URL_AND_MARKER = URL + Optional(MARKER)
  
  
  
  NAMED_REQUIREMENT = NAME + Optional(EXTRAS) + (URL_AND_MARKER | VERSION_AND_MARKER)
  
  
  
  REQUIREMENT = stringStart + NAMED_REQUIREMENT + stringEnd
  
  # pyparsing isn't thread safe during initialization, so we do it eagerly, see
  
  # issue #104
  
  REQUIREMENT.parseString("x[]")
  
  
  
  
  
  class Requirement(object):
  
      """Parse a requirement.
  
  
  
      Parse a given requirement string into its parts, such as name, specifier,
  
      URL, and extras. Raises InvalidRequirement on a badly-formed requirement
  
      string.
  
      """
  
  
  
      # TODO: Can we test whether something is contained within a requirement?
  
      #       If so how do we do that? Do we need to test against the _name_ of
  
      #       the thing as well as the version? What about the markers?
  
      # TODO: Can we normalize the name and extra name?
  
  
  
      def __init__(self, requirement_string):
  
          # type: (str) -> None
  
          try:
  
              req = REQUIREMENT.parseString(requirement_string)
  
          except ParseException as e:
  
              raise InvalidRequirement(
  
                  'Parse error at "{0!r}": {1}'.format(
  
                      requirement_string[e.loc : e.loc + 8], e.msg
  
                  )
  
              )
  
  
  
          self.name = req.name  # type: str
  
          if req.url:
  
              parsed_url = urlparse.urlparse(req.url)
  
              if parsed_url.scheme == "file":
  
                  if urlparse.urlunparse(parsed_url) != req.url:
  
                      raise InvalidRequirement("Invalid URL given")
  
              elif not (parsed_url.scheme and parsed_url.netloc) or (
  
                  not parsed_url.scheme and not parsed_url.netloc
  
              ):
  
                  raise InvalidRequirement("Invalid URL: {0}".format(req.url))
  
              self.url = req.url  # type: TOptional[str]
  
          else:
  
              self.url = None
  
          self.extras = set(req.extras.asList() if req.extras else [])  # type: Set[str]
  
          self.specifier = SpecifierSet(req.specifier)  # type: SpecifierSet
  
          self.marker = req.marker if req.marker else None  # type: TOptional[Marker]
  
  
  
      def __str__(self):
  
          # type: () -> str
  
          parts = [self.name]  # type: List[str]
  
  
  
          if self.extras:
  
              parts.append("[{0}]".format(",".join(sorted(self.extras))))
  
  
  
          if self.specifier:
  
              parts.append(str(self.specifier))
  
  
  
          if self.url:
  
              parts.append("@ {0}".format(self.url))
  
              if self.marker:
  
                  parts.append(" ")
  
  
  
          if self.marker:
  
              parts.append("; {0}".format(self.marker))
  
  
  
          return "".join(parts)
  
  
  
      def __repr__(self):
  
          # type: () -> str
  
          return "<Requirement({0!r})>".format(str(self))
  
  