Improve PEP-440 support for versions

This is a broad change aligning `poetry.core.semver.version.Version`
implementation to be closer to PEP-440 that to semver. This adds the
foundation for improved dev and local tag support in poetry managed
version as well as fix ordering bugs that existed due to the
differences between semantic versioning specification and PEP-440.

Further, previously used inline copy of `packaging.version.Version`
implementation has now been removed in favour of
`poetry.core.version.pep440.PEP440Version` implementation.

poetry/core/packages/dependency.py

@@ -62,7 +62,7 @@ def __init__(
 
         if isinstance(self._constraint, VersionRange) and self._constraint.min:
             allows_prereleases = (
-                allows_prereleases or self._constraint.min.is_prerelease()
+                allows_prereleases or self._constraint.min.is_pre_release()
             )
 
         self._allows_prereleases = allows_prereleases

poetry/core/packages/package.py

@@ -305,7 +305,7 @@ def urls(self) -> Dict[str, str]:
         return urls
 
     def is_prerelease(self) -> bool:
-        return self._version.is_prerelease()
+        return self._version.is_pre_release()
 
     def is_root(self) -> bool:
         return False

poetry/core/semver/helpers.py

@@ -69,10 +69,9 @@ def parse_single_constraint(constraint: str) -> VersionTypes:
     m = TILDE_CONSTRAINT.match(constraint)
     if m:
         version = Version.parse(m.group(1))
-
-        high = version.stable.next_minor
+        high = version.stable.next_minor()
         if len(m.group(1).split(".")) == 1:
-            high = version.stable.next_major
+            high = version.stable.next_major()
 
         return VersionRange(version, high, include_min=True)
 
@@ -89,9 +88,9 @@ def parse_single_constraint(constraint: str) -> VersionTypes:
         version = Version.parse(m.group(1))
 
         if precision == 2:
-            high = version.stable.next_major
+            high = version.stable.next_major()
         else:
-            high = version.stable.next_minor
+            high = version.stable.next_minor()
 
         return VersionRange(version, high, include_min=True)
 
@@ -100,7 +99,7 @@ def parse_single_constraint(constraint: str) -> VersionTypes:
     if m:
         version = Version.parse(m.group(1))
 
-        return VersionRange(version, version.next_breaking, include_min=True)
+        return VersionRange(version, version.next_breaking(), include_min=True)
 
     # X Range
     m = X_CONSTRAINT.match(constraint)
@@ -110,16 +109,15 @@ def parse_single_constraint(constraint: str) -> VersionTypes:
         minor = m.group(3)
 
         if minor is not None:
-            version = Version(major, int(minor), 0)
-
-            result = VersionRange(version, version.next_minor, include_min=True)
+            version = Version.from_parts(major, int(minor), 0)
+            result = VersionRange(version, version.next_minor(), include_min=True)
         else:
             if major == 0:
-                result = VersionRange(max=Version(1, 0, 0))
+                result = VersionRange(max=Version.from_parts(1, 0, 0))
             else:
-                version = Version(major, 0, 0)
+                version = Version.from_parts(major, 0, 0)
 
-                result = VersionRange(version, version.next_major, include_min=True)
+                result = VersionRange(version, version.next_major(), include_min=True)
 
         if op == "!=":
             result = VersionRange().difference(result)