Add basic "Requirement" class that can tell whether a distribution or

version meets its version requirements.

--HG--
branch : setuptools
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/trunk/setuptools%4041005

2 files changed, 98 insertions, 16 deletions

diff --git a/pkg_resources.py b/pkg_resources.py
index a3f9ee7c..f3669f6e 100644
--- a/pkg_resources.py
+++ b/pkg_resources.py
@@ -19,7 +19,7 @@ __all__ = [
     'resource_stream', 'resource_filename', 'set_extraction_path',
     'cleanup_resources', 'parse_requirements', 'parse_version',
     'compatible_platforms', 'get_platform',
-    'Distribution', # 'glob_resources'
+    'Distribution', 'Requirement', # 'glob_resources'
 ]
 
 import sys, os, zipimport, time, re
@@ -740,7 +740,7 @@ def parse_requirements(strs):
     """Yield ``Requirement`` objects for each specification in `strs`
 
     `strs` must be an instance of ``basestring``, or a (possibly-nested)
-    sequence thereof.
+    iterable thereof.
     """
     # create a steppable iterator, so we can handle \-continuations
     lines = iter(yield_lines(strs))
@@ -772,11 +772,62 @@ def parse_requirements(strs):
             elif not LINE_END(line,p):
                 raise ValueError("Expected ',' or EOL in",line,"at",line[p:])
 
-        yield distname.replace('_','-'), specs
+        yield Requirement(distname.replace('_','-'), specs)
 
 
 
 
+class Requirement:
+
+    def __init__(self, distname, specs=()):
+        self.distname = distname
+        self.key = distname.lower()
+        index = [(parse_version(v),state_machine[op],op,v) for op,v in specs]
+        index.sort()
+        self.specs = [(op,ver) for parsed,trans,op,ver in index]
+        self.index = index
+
+    def __str__(self):
+        return self.distname + ','.join([''.join(s) for s in self.specs])
+
+    def __repr__(self):
+        return "Requirement(%r, %r)" % (self.distname, self.specs)
+
+    def __eq__(self,other):
+        return isinstance(other,Requirement) \
+            and self.key==other.key and self.specs==other.specs
+
+    def __contains__(self,item):
+        if isinstance(item,Distribution):
+            if item.key <> self.key:
+                return False
+            item = item.parsed_version
+        elif isinstance(item,basestring):
+            item = parse_version(item)
+        last = True
+        for parsed,trans,op,ver in self.index:
+            action = trans[cmp(item,parsed)]
+            if action=='F':
+                return False
+            elif action=='T':
+                return True
+            elif action=='+':
+                last = True
+            elif action=='-':
+                last = False
+        return last
+
+
+state_machine = {
+    #       =><
+    '<' :  '--T',
+    '<=':  'T-T',
+    '>' :  'F+F',
+    '>=':  'T+F',
+    '==':  'T..',
+    '!=':  'F..',
+}
+
 def _get_mro(cls):
     """Get an mro for a type or classic class"""
     if not isinstance(cls,type):
@@ -808,13 +859,3 @@ def _initialize(g):
 _initialize(globals())
 
 
-
-
-
-
-
-
-
-
-
-
diff --git a/setuptools/tests/test_resources.py b/setuptools/tests/test_resources.py
index b2b5c2ce..52197fe9 100644
--- a/setuptools/tests/test_resources.py
+++ b/setuptools/tests/test_resources.py
@@ -80,6 +80,47 @@ class DistroTests(TestCase):
 
 
 
+class RequirementsTests(TestCase):
+
+    def testBasics(self):
+        r = Requirement("Twisted", [('>=','1.2')])
+        self.assertEqual(str(r),"Twisted>=1.2")
+        self.assertEqual(repr(r),"Requirement('Twisted', [('>=', '1.2')])")
+        self.assertEqual(r, Requirement("Twisted", [('>=','1.2')]))
+        self.assertEqual(r, Requirement("twisTed", [('>=','1.2')]))
+        self.assertNotEqual(r, Requirement("Twisted", [('>=','2.0')]))
+        self.assertNotEqual(r, Requirement("Zope", [('>=','1.2')]))
+        self.assertNotEqual(r, Requirement("Zope", [('>=','3.0')]))
+
+    def testOrdering(self):
+        r1 = Requirement("Twisted", [('==','1.2c1'),('>=','1.2')])
+        r2 = Requirement("Twisted", [('>=','1.2'),('==','1.2c1')])
+        self.assertEqual(r1,r2)
+        self.assertEqual(str(r1),str(r2))
+        self.assertEqual(str(r2),"Twisted==1.2c1,>=1.2")
+
+    def testBasicContains(self):
+        r = Requirement("Twisted", [('>=','1.2')])
+        foo_dist = Distribution.from_filename("FooPkg-1.3_1.egg")
+        twist11  = Distribution.from_filename("Twisted-1.1.egg")
+        twist12  = Distribution.from_filename("Twisted-1.2.egg")
+        self.failUnless(parse_version('1.2') in r)
+        self.failUnless(parse_version('1.1') not in r)
+        self.failUnless('1.2' in r)
+        self.failUnless('1.1' not in r)
+        self.failUnless(foo_dist not in r)
+        self.failUnless(twist11 not in r)
+        self.failUnless(twist12 in r)
+
+    def testAdvancedContains(self):
+        r, = parse_requirements("Foo>=1.2,<=1.3,==1.9,>2.0,!=2.5,<3.0,==4.5")
+        for v in ('1.2','1.2.2','1.3','1.9','2.0.1','2.3','2.6','3.0c1','4.5'):
+            self.failUnless(v in r, (v,r))
+        for v in ('1.2c1','1.3.1','1.5','1.9.1','2.0','2.5','3.0','4.0'):
+            self.failUnless(v not in r, (v,r))
+
+
+
 class ParseTests(TestCase):
 
     def testEmptyParse(self):
@@ -92,14 +133,14 @@ class ParseTests(TestCase):
         ]:
             self.assertEqual(list(pkg_resources.yield_lines(inp)),out)
 
-    def testSimple(self):
+    def testSimpleRequirements(self):
         self.assertEqual(
             list(parse_requirements('Twis-Ted>=1.2-1')),
-            [('Twis-Ted',[('>=','1.2-1')])]
+            [Requirement('Twis-Ted',[('>=','1.2-1')])]
         )
         self.assertEqual(
             list(parse_requirements('Twisted >=1.2, \ # more\n<2.0')),
-            [('Twisted',[('>=','1.2'),('<','2.0')])]
+            [Requirement('Twisted',[('>=','1.2'),('<','2.0')])]
         )
         self.assertRaises(ValueError,lambda:list(parse_requirements(">=2.3")))
         self.assertRaises(ValueError,lambda:list(parse_requirements("x\\")))