1 files changed, 490 insertions, 0 deletions
diff --git a/semantic_version/base.py b/semantic_version/base.py
new file mode 100644
index 0000000..f5153b2
--- /dev/null
+++ b/semantic_version/base.py
@@ -0,0 +1,490 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2012-2013 Raphaël Barrois
+# This code is distributed under the two-clause BSD License.
+
+from __future__ import unicode_literals
+
+import functools
+import re
+
+
+from .compat import base_cmp
+
+def _to_int(value):
+    try:
+        return int(value), True
+    except ValueError:
+        return value, False
+
+
+def identifier_cmp(a, b):
+    """Compare two identifier (for pre-release/build components)."""
+
+    a_cmp, a_is_int = _to_int(a)
+    b_cmp, b_is_int = _to_int(b)
+
+    if a_is_int and b_is_int:
+        # Numeric identifiers are compared as integers
+        return base_cmp(a_cmp, b_cmp)
+    elif a_is_int:
+        # Numeric identifiers have lower precedence
+        return -1
+    elif b_is_int:
+        return 1
+    else:
+        # Non-numeric identifers are compared lexicographically
+        return base_cmp(a_cmp, b_cmp)
+
+
+def identifier_list_cmp(a, b):
+    """Compare two identifier list (pre-release/build components).
+
+    The rule is:
+        - Identifiers are paired between lists
+        - They are compared from left to right
+        - If all first identifiers match, the longest list is greater.
+
+    >>> identifier_list_cmp(['1', '2'], ['1', '2'])
+    0
+    >>> identifier_list_cmp(['1', '2a'], ['1', '2b'])
+    -1
+    >>> identifier_list_cmp(['1'], ['1', '2'])
+    -1
+    """
+    identifier_pairs = zip(a, b)
+    for id_a, id_b in identifier_pairs:
+        cmp_res = identifier_cmp(id_a, id_b)
+        if cmp_res != 0:
+            return cmp_res
+    # alpha1.3 < alpha1.3.1
+    return base_cmp(len(a), len(b))
+
+
+class Version(object):
+
+    version_re = re.compile('^(\d+)\.(\d+)\.(\d+)(?:-([0-9a-zA-Z.-]+))?(?:\+([0-9a-zA-Z.-]+))?$')
+    partial_version_re = re.compile('^(\d+)(?:\.(\d+)(?:\.(\d+))?)?(?:-([0-9a-zA-Z.-]*))?(?:\+([0-9a-zA-Z.-]*))?$')
+
+    def __init__(self, version_string, partial=False):
+        major, minor, patch, prerelease, build = self.parse(version_string, partial)
+
+        self.major = major
+        self.minor = minor
+        self.patch = patch
+        self.prerelease = prerelease
+        self.build = build
+
+        self.partial = partial
+
+    @classmethod
+    def _coerce(cls, value, allow_none=False):
+        if value is None and allow_none:
+            return value
+        return int(value)
+
+    @classmethod
+    def coerce(cls, version_string, partial=False):
+        """Coerce an arbitrary version string into a semver-compatible one.
+
+        The rule is:
+        - If not enough components, fill minor/patch with zeroes; unless
+          partial=True
+        - If more than 3 dot-separated components, extra components are "build"
+          data. If some "build" data already appeared, append it to the
+          extra components
+
+        Examples:
+            >>> Version.coerce('0.1')
+            Version(0, 1, 0)
+            >>> Version.coerce('0.1.2.3')
+            Version(0, 1, 2, (), ('3',))
+            >>> Version.coerce('0.1.2.3+4')
+            Version(0, 1, 2, (), ('3', '4'))
+            >>> Version.coerce('0.1+2-3+4_5')
+            Version(0, 1, 0, (), ('2-3', '4-5'))
+        """
+        base_re = re.compile(r'^\d+(?:\.\d+(?:\.\d+)?)?')
+
+        match = base_re.match(version_string)
+        if not match:
+            raise ValueError("Version string lacks a numerical component: %r"
+                    % version_string)
+
+        version = version_string[:match.end()]
+        if not partial:
+            # We need a not-partial version.
+            while version.count('.') < 2:
+                version += '.0'
+
+        if match.end() == len(version_string):
+            return Version(version, partial=partial)
+
+        rest = version_string[match.end():]
+
+        # Cleanup the 'rest'
+        rest = re.sub(r'[^a-zA-Z0-9+.-]', '-', rest)
+
+        if rest[0] == '+':
+            # A 'build' component
+            prerelease = ''
+            build = rest[1:]
+        elif rest[0] == '.':
+            # An extra version component, probably 'build'
+            prerelease = ''
+            build = rest[1:]
+        elif rest[0] == '-':
+            rest = rest[1:]
+            if '+' in rest:
+                prerelease, build = rest.split('+', 1)
+            else:
+                prerelease, build = rest, ''
+        elif '+' in rest:
+            prerelease, build = rest.split('+', 1)
+        else:
+            prerelease, build = rest, ''
+
+        build = build.replace('+', '.')
+
+        if prerelease:
+            version = '%s-%s' % (version, prerelease)
+        if build:
+            version = '%s+%s' % (version, build)
+
+        return cls(version, partial=partial)
+
+    @classmethod
+    def parse(cls, version_string, partial=False, coerce=False):
+        """Parse a version string into a Version() object.
+
+        Args:
+            version_string (str), the version string to parse
+            partial (bool), whether to accept incomplete input
+            coerce (bool), whether to try to map the passed in string into a
+                valid Version.
+        """
+        if not version_string:
+            raise ValueError('Invalid empty version string: %r' % version_string)
+
+        if partial:
+            version_re = cls.partial_version_re
+        else:
+            version_re = cls.version_re
+
+        match = version_re.match(version_string)
+        if not match:
+            raise ValueError('Invalid version string: %r' % version_string)
+
+        major, minor, patch, prerelease, build = match.groups()
+
+        major = int(major)
+        minor = cls._coerce(minor, partial)
+        patch = cls._coerce(patch, partial)
+
+        if prerelease is None:
+            if partial and (build is None):
+                # No build info, strip here
+                return (major, minor, patch, None, None)
+            else:
+                prerelease = ()
+        elif prerelease == '':
+            prerelease = ()
+        else:
+            prerelease = tuple(prerelease.split('.'))
+
+        if build is None:
+            if partial:
+                build = None
+            else:
+                build = ()
+        elif build == '':
+            build = ()
+        else:
+            build = tuple(build.split('.'))
+
+        return (major, minor, patch, prerelease, build)
+
+    def __iter__(self):
+        return iter((self.major, self.minor, self.patch, self.prerelease, self.build))
+
+    def __str__(self):
+        version = '%d' % self.major
+        if self.minor is not None:
+            version = '%s.%d' % (version, self.minor)
+        if self.patch is not None:
+            version = '%s.%d' % (version, self.patch)
+
+        if self.prerelease or (self.partial and self.prerelease == () and self.build is None):
+            version = '%s-%s' % (version, '.'.join(self.prerelease))
+        if self.build or (self.partial and self.build == ()):
+            version = '%s+%s' % (version, '.'.join(self.build))
+        return version
+
+    def __repr__(self):
+        return 'Version(%r%s)' % (
+            str(self),
+            ', partial=True' if self.partial else '',
+        )
+
+    @classmethod
+    def _comparison_functions(cls, partial=False):
+        """Retrieve comparison methods to apply on version components.
+
+        This is a private API.
+
+        Args:
+            partial (bool): whether to provide 'partial' or 'strict' matching.
+
+        Returns:
+            5-tuple of cmp-like functions.
+        """
+
+        def prerelease_cmp(a, b):
+            """Compare prerelease components.
+
+            Special rule: a version without prerelease component has higher
+            precedence than one with a prerelease component.
+            """
+            if a and b:
+                return identifier_list_cmp(a, b)
+            elif a:
+                # Versions with prerelease field have lower precedence
+                return -1
+            elif b:
+                return 1
+            else:
+                return 0
+
+        def build_cmp(a, b):
+            """Compare build components.
+
+            Special rule: a version without build component has lower
+            precedence than one with a build component.
+            """
+            if a and b:
+                return identifier_list_cmp(a, b)
+            elif a:
+                # Versions with build field have higher precedence
+                return 1
+            elif b:
+                return -1
+            else:
+                return 0
+
+        def make_optional(orig_cmp_fun):
+            """Convert a cmp-like function to consider 'None == *'."""
+            @functools.wraps(orig_cmp_fun)
+            def alt_cmp_fun(a, b):
+                if a is None or b is None:
+                    return 0
+                return orig_cmp_fun(a, b)
+
+            return alt_cmp_fun
+
+        if partial:
+            return [
+                base_cmp,  # Major is still mandatory
+                make_optional(base_cmp),
+                make_optional(base_cmp),
+                make_optional(prerelease_cmp),
+                make_optional(build_cmp),
+            ]
+        else:
+            return [
+                base_cmp,
+                base_cmp,
+                base_cmp,
+                prerelease_cmp,
+                build_cmp,
+            ]
+
+    def __cmp__(self, other):
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+
+        field_pairs = zip(self, other)
+        comparison_functions = self._comparison_functions(partial=self.partial or other.partial)
+        comparisons = zip(comparison_functions, self, other)
+
+        for cmp_fun, self_field, other_field in comparisons:
+            cmp_res = cmp_fun(self_field, other_field)
+            if cmp_res != 0:
+                return cmp_res
+
+        return 0
+
+    def __eq__(self, other):
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self.__cmp__(other) == 0
+
+    def __hash__(self):
+        return hash((self.major, self.minor, self.patch, self.prerelease, self.build))
+
+    def __ne__(self, other):
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self.__cmp__(other) != 0
+
+    def __lt__(self, other):
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self.__cmp__(other) < 0
+
+    def __le__(self, other):
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self.__cmp__(other) <= 0
+
+    def __gt__(self, other):
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self.__cmp__(other) > 0
+
+    def __ge__(self, other):
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self.__cmp__(other) >= 0
+
+
+class SpecItem(object):
+    """A requirement specification."""
+
+    KIND_LT = '<'
+    KIND_LTE = '<='
+    KIND_EQUAL = '=='
+    KIND_GTE = '>='
+    KIND_GT = '>'
+    KIND_NEQ = '!='
+
+    STRICT_KINDS = (
+        KIND_LT,
+        KIND_LTE,
+        KIND_EQUAL,
+        KIND_GTE,
+        KIND_GT,
+        KIND_NEQ,
+    )
+
+    re_spec = re.compile(r'^(<|<=|==|>=|>|!=)(\d.*)$')
+
+    def __init__(self, requirement_string):
+        kind, spec = self.parse(requirement_string)
+        self.kind = kind
+        self.spec = spec
+
+    @classmethod
+    def parse(cls, requirement_string):
+        if not requirement_string:
+            raise ValueError("Invalid empty requirement specification: %r" % requirement_string)
+
+        match = cls.re_spec.match(requirement_string)
+        if not match:
+            raise ValueError("Invalid requirement specification: %r" % requirement_string)
+
+        kind, version = match.groups()
+        spec = Version(version, partial=True)
+        return (kind, spec)
+
+    def match(self, version):
+        if self.kind == self.KIND_LT:
+            return version < self.spec
+        elif self.kind == self.KIND_LTE:
+            return version <= self.spec
+        elif self.kind == self.KIND_EQUAL:
+            return version == self.spec
+        elif self.kind == self.KIND_GTE:
+            return version >= self.spec
+        elif self.kind == self.KIND_GT:
+            return version > self.spec
+        elif self.kind == self.KIND_NEQ:
+            return version != self.spec
+        else:  # pragma: no cover
+            raise ValueError('Unexpected match kind: %r' % self.kind)
+
+    def __str__(self):
+        return '%s%s' % (self.kind, self.spec)
+
+    def __repr__(self):
+        return '<SpecItem: %s %r>' % (self.kind, self.spec)
+
+    def __eq__(self, other):
+        if not isinstance(other, SpecItem):
+            return NotImplemented
+        return self.kind == other.kind and self.spec == other.spec
+
+    def __hash__(self):
+        return hash((self.kind, self.spec))
+
+
+class Spec(object):
+    def __init__(self, *specs_strings):
+        subspecs = [self.parse(spec) for spec in specs_strings]
+        self.specs = sum(subspecs, ())
+
+    @classmethod
+    def parse(self, specs_string):
+        spec_texts = specs_string.split(',')
+        return tuple(SpecItem(spec_text) for spec_text in spec_texts)
+
+    def match(self, version):
+        """Check whether a Version satisfies the Spec."""
+        return all(spec.match(version) for spec in self.specs)
+
+    def filter(self, versions):
+        """Filter an iterable of versions satisfying the Spec."""
+        for version in versions:
+            if self.match(version):
+                yield version
+
+    def select(self, versions):
+        """Select the best compatible version among an iterable of options."""
+        options = list(self.filter(versions))
+        if options:
+            return max(options)
+        return None
+
+    def __contains__(self, version):
+        if isinstance(version, Version):
+            return self.match(version)
+        return False
+
+    def __iter__(self):
+        return iter(self.specs)
+
+    def __str__(self):
+        return ','.join(str(spec) for spec in self.specs)
+
+    def __repr__(self):
+        return '<Spec: %r>' % (self.specs,)
+
+    def __eq__(self, other):
+        if not isinstance(other, Spec):
+            return NotImplemented
+
+        return set(self.specs) == set(other.specs)
+
+    def __hash__(self):
+        return hash(self.specs)
+
+
+def compare(v1, v2):
+    return base_cmp(Version(v1), Version(v2))
+
+
+def match(spec, version):
+    return Spec(spec).match(Version(version))
+
+
+def validate(version_string):
+    """Validates a version string againt the SemVer specification."""
+    try:
+        Version.parse(version_string)
+        return True
+    except ValueError:
+        return False