set builtin: add difference and difference_update builtins

- added basic unittest

Author: cosminbasca

graalpython/com.oracle.graal.python.test/src/tests/test_set.py

@@ -39,6 +39,24 @@
 # Iterating by Sequence Index
 
 
+def assert_raises(err, fn, *args, **kwargs):
+    raised = False
+    try:
+        fn(*args, **kwargs)
+    except err:
+        raised = True
+    assert raised
+
+
+class PassThru(Exception):
+    pass
+
+
+def check_pass_thru():
+    raise PassThru
+    yield 1
+
+
 def test_set_or():
     s1 = {1, 2, 3}
     s2 = {4, 5, 6}
@@ -65,3 +83,64 @@ def test_set_remove():
 def test_set_le():
     assert set("a") <= set("abc")
 
+
+def test_difference():
+    word = 'simsalabim'
+    otherword = 'madagascar'
+    letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
+    s = set(word)
+    d = dict.fromkeys(word)
+
+    i = s.difference(otherword)
+    for c in letters:
+        assert (c in i) == (c in d and c not in otherword)
+
+    assert s == set(word)
+    assert type(i) == set
+    assert_raises(PassThru, s.difference, check_pass_thru())
+    assert_raises(TypeError, s.difference, [[]])
+
+    for C in set, frozenset, dict.fromkeys, str, list, tuple:
+        assert set('abcba').difference(C('cdc')) == set('ab')
+        assert set('abcba').difference(C('efgfe')) == set('abc')
+        assert set('abcba').difference(C('ccb')) == set('a')
+        assert set('abcba').difference(C('ef')) == set('abc')
+        assert set('abcba').difference() == set('abc')
+        assert set('abcba').difference(C('a'), C('b')) == set('c')
+
+
+def test_difference_update():
+    word = 'simsalabim'
+    otherword = 'madagascar'
+    s = set(word)
+
+    retval = s.difference_update(otherword)
+    assert retval == None
+
+    for c in (word + otherword):
+        if c in word and c not in otherword:
+            assert c in s
+        else:
+            assert c not in s
+
+    assert_raises(PassThru, s.difference_update, check_pass_thru())
+    assert_raises(TypeError, s.difference_update, [[]])
+    # assert_raises(TypeError, s.symmetric_difference_update, [[]])
+
+    for p, q in (('cdc', 'ab'), ('efgfe', 'abc'), ('ccb', 'a'), ('ef', 'abc')):
+        for C in set, frozenset, dict.fromkeys, str, list, tuple:
+            s = set('abcba')
+            assert s.difference_update(C(p)) == None
+            assert s == set(q)
+
+            s = set('abcdefghih')
+            s.difference_update()
+            assert s == set('abcdefghih')
+
+            s = set('abcdefghih')
+            s.difference_update(C('aba'))
+            assert s == set('cdefghih')
+
+            s = set('abcdefghih')
+            s.difference_update(C('cdc'), C('aba'))
+            assert s == set('efghih')

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/set/PSet.java

@@ -71,5 +71,4 @@ public void clear() {
     public void setDictStorage(HashingStorage newStorage) {
         throw new RuntimeException("set has fixed storage");
     }
-
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/set/SetNodes.java

@@ -40,6 +40,7 @@
 
 import static com.oracle.graal.python.runtime.exception.PythonErrorType.TypeError;
 
+import com.oracle.graal.python.builtins.PythonBuiltinClassType;
 import com.oracle.graal.python.builtins.objects.PNone;
 import com.oracle.graal.python.builtins.objects.common.HashingStorageNodes.SetItemNode;
 import com.oracle.graal.python.builtins.objects.type.PythonClass;
@@ -67,6 +68,10 @@ public abstract static class ConstructSetNode extends PBaseNode {
 
         public abstract PSet execute(Object cls, Object value);
 
+        public final PSet executeWith(Object value) {
+            return this.execute(lookupClass(PythonBuiltinClassType.PSet), value);
+        }
+
         @Specialization
         @TruffleBoundary
         public PSet setString(PythonClass cls, String arg) {

graalpython/lib-graalpython/set.py

@@ -35,6 +35,7 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
+
 def update(self, *others):
     for seq in others:
         if not hasattr(seq, '__iter__'):
@@ -44,6 +45,26 @@ def update(self, *others):
             self.add(el)
 
 
+def difference(self, *others):
+    diff_set = self
+    for seq in others:
+        diff_set = set(el for el in diff_set if el not in set(seq))
+    return diff_set
+
+
+def difference_update(self, *others):
+    for seq in others:
+        other_set = set(seq)
+        self_copy = set(self)
+        for el in self_copy:
+            if el in other_set:
+                self.remove(el)
+
+
+def frozenset_difference(self, *others):
+    return frozenset(difference(self, *others))
+
+
 def set_repr(self):
     if len(self):
         s = "{"
@@ -83,7 +104,11 @@ def frozenset_copy(self):
 
 
 set.update = update
+set.difference = difference
+set.difference_update = difference_update
 set.__repr__ = set_repr
 set.copy = set_copy
+
+frozenset.difference = frozenset_difference
 frozenset.__repr__ = frozenset_repr
 frozenset.copy = frozenset_copy