Add `Version.precedence_key`.

This will be used in `sort(..., key=lambda v: v.precedence_key)`.
Remove previous comparison/ordering implementation.

The current implementation relies on a 4-tuple:
- major, minor, patch (as integers) - natural order matches precedence
  rules
- a tuple of identifiers for the prerelease component.

The identifiers for the prerelease components are based on:
- A `NumericIdentifier` class, that compares number using their natural
  order, and always compares lower than non-numeric identifiers
- A `AlphaIdentifier` class for non-numeric identifiers; it compares
  versions using ASCII ordering.
- A `MaxIdentifier` class, that compares higher to any other identifier;
  used to ensure that a non-prerelease version is greater than any of
  its prereleases.

2 files changed, 2 insertions, 53 deletions

diff --git a/tests/test_base.py b/tests/test_base.py
index d5794b3..5a6497b 100755
--- a/tests/test_base.py
+++ b/tests/test_base.py
@@ -10,57 +10,6 @@ import unittest
 from semantic_version import base
 
 
-class ComparisonTestCase(unittest.TestCase):
-    def test_identifier_cmp(self):
-        cases = [
-            # Integers
-            ('1', '1', 0),
-            ('1', '2', -1),
-            ('11', '2', 1),
-            ('3333', '40', 1),
-
-            # Text
-            ('aa', 'ab', -1),
-            ('aa', 'aa', 0),
-            ('ab', 'aa', 1),
-            ('aaa', 'ab', -1),
-
-            # Mixed
-            ('10', '1a', -1),
-            ('1a', '10', 1),
-            ('ab1', '42', 1),
-        ]
-
-        for a, b, expected in cases:
-            with self.subTest(a=a, b=b):
-                result = base.identifier_cmp(a, b)
-                self.assertEqual(
-                    expected, result,
-                    "identifier_cmp(%r, %r) returned %d instead of %d" % (
-                        a, b, result, expected))
-
-    def test_identifier_list_cmp(self):
-        cases = [
-            # Same length
-            (['1', '2', '3'], ['1', '2', '3'], 0),
-            (['1', '2', '3'], ['1', '3', '2'], -1),
-            (['1', '2', '4'], ['1', '2', '3'], 1),
-
-            # Mixed lengths
-            (['1', 'a'], ['1', 'a', '0'], -1),
-            (['1', 'a', '0'], ['1', 'a'], 1),
-            (['1', 'b'], ['1', 'a', '1000'], 1),
-        ]
-
-        for a, b, expected in cases:
-            with self.subTest(a=a, b=b):
-                result = base.identifier_list_cmp(a, b)
-                self.assertEqual(
-                    expected, result,
-                    "identifier_list_cmp(%r, %r) returned %d instead of %d" % (
-                        a, b, result, expected))
-
-
 class TopLevelTestCase(unittest.TestCase):
     """Test module-level functions."""
 
diff --git a/tests/test_parsing.py b/tests/test_parsing.py
index 2d612a1..0da679f 100755
--- a/tests/test_parsing.py
+++ b/tests/test_parsing.py
@@ -120,9 +120,9 @@ class ComparisonTestCase(unittest.TestCase):
                     self.assertFalse(v1 == v2, "%r == %r" % (v1, v2))
                     self.assertTrue(v1 != v2, "%r !!= %r" % (v1, v2))
                     self.assertFalse(v1 < v2, "%r !< %r" % (v1, v2))
-                    self.assertFalse(v1 <= v2, "%r !<= %r" % (v1, v2))
+                    self.assertTrue(v1 <= v2, "%r !<= %r" % (v1, v2))
                     self.assertFalse(v2 > v1, "%r !> %r" % (v2, v1))
-                    self.assertFalse(v2 >= v1, "%r !>= %r" % (v2, v1))
+                    self.assertTrue(v2 >= v1, "%r !>= %r" % (v2, v1))
 
 
 if __name__ == '__main__':  # pragma: no cover