Merge pull request #164. Fixes #122.

1 files changed, 120 insertions, 0 deletions

diff --git a/pkg_resources/_vendor/packaging/requirements.py b/pkg_resources/_vendor/packaging/requirements.py
new file mode 100644
index 00000000..dc3672e7
--- /dev/null
+++ b/pkg_resources/_vendor/packaging/requirements.py
@@ -0,0 +1,120 @@
+# 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 string
+import re
+
+from pkg_resources._vendor.pyparsing import stringStart, stringEnd, originalTextFor, ParseException
+from pkg_resources._vendor.pyparsing import ZeroOrMore, Word, Optional, Regex, Combine
+from pkg_resources._vendor.pyparsing import Literal as L  # noqa
+from six.moves.urllib import parse as urlparse
+
+from .markers import MARKER_EXPR, Marker
+from .specifiers import LegacySpecifier, Specifier, SpecifierSet
+
+
+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=",")("_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_SEPERATOR = SEMICOLON
+MARKER = MARKER_SEPERATOR + 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
+
+
+class Requirement(object):
+
+    # 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):
+        try:
+            req = REQUIREMENT.parseString(requirement_string)
+        except ParseException:
+            raise InvalidRequirement(
+                "Invalid requirement: {0!r}".format(requirement_string))
+
+        self.name = req.name
+        if req.url:
+            parsed_url = urlparse.urlparse(req.url)
+            if not (parsed_url.scheme and parsed_url.netloc) or (
+                    not parsed_url.scheme and not parsed_url.netloc):
+                raise InvalidRequirement("Invalid URL given")
+            self.url = req.url
+        else:
+            self.url = None
+        self.extras = req.extras.asList() if req.extras else []
+        self.specifier = SpecifierSet(req.specifier)
+        self.marker = req.marker if req.marker else None
+
+    def __str__(self):
+        parts = [self.name]
+
+        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("; {0}".format(self.marker))
+
+        return "".join(parts)
+
+    def __repr__(self):
+        return "<Requirement({0!r})>".format(str(self))