Add concatenation operators for cypclass builtin list and associated unit tests

Cython/Includes/libcythonplus/list.pxd

@@ -97,6 +97,58 @@ cdef cypclass cyplist[V]:
             with gil:
                 raise RuntimeError("Modifying a list with active iterators")
 
+    cyplist[V] __add__(self, const cyplist[V] other) const:
+        result = cyplist[V]()
+        result._elements.reserve(self._elements.size() + other._elements.size())
+        for value in self._elements:
+            Cy_INCREF(value)
+            result._elements.push_back(value)
+        for value in other._elements:
+            Cy_INCREF(value)
+            result._elements.push_back(value)
+        return result
+
+    cyplist[V] __iadd__(self, const cyplist[V] other):
+        if self._active_iterators == 0:
+            self._elements.reserve(self._elements.size() + other._elements.size())
+            for value in other._elements:
+                Cy_INCREF(value)
+                self._elements.push_back(value)
+            return self
+        else:
+            with gil:
+                raise RuntimeError("Modifying a list with active iterators")
+
+    cyplist[V] __mul__(self, size_type n) const:
+        result = cyplist[V]()
+        result._elements.reserve(self._elements.size() * n)
+        for i in range(n):
+            for value in self._elements:
+                Cy_INCREF(value)
+                result._elements.push_back(value)
+        return result
+
+    cyplist[V] __imul__(self, size_type n):
+        if self._active_iterators == 0:
+            if n > 1:
+                elements = self._elements
+                self._elements.reserve(elements.size() * n)
+                for i in range(1, n):
+                    for value in elements:
+                        Cy_INCREF(value)
+                        self._elements.push_back(value)
+                return self
+            elif n == 1:
+                return self
+            else:
+                for value in self._elements:
+                    Cy_DECREF(value)
+                self._elements.clear()
+                return self
+        else:
+            with gil:
+                raise RuntimeError("Modifying a list with active iterators")
+
     list_iterator_t[cyplist[V], vector[value_type].iterator, value_type] begin(self) const:
         return list_iterator_t[cyplist[V], vector[value_type].iterator, value_type](self._elements.begin(), self)
 

tests/run/cypclass_builtin_list.pyx

@@ -103,6 +103,56 @@ def test_contains():
             return 0
     return 1
 
+def test_add():
+    """
+    >>> test_add()
+    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+    """
+    l1 = cyplist[Value]()
+    for i in range(5):
+        l1.append(Value(i))
+    l2 = cyplist[Value]()
+    for i in range(5, 10):
+        l2.append(Value(i))
+    l = l1 + l2
+    return [v.value for v in l]
+
+def test_iadd():
+    """
+    >>> test_iadd()
+    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+    """
+    l1 = cyplist[Value]()
+    for i in range(5):
+        l1.append(Value(i))
+    l2 = cyplist[Value]()
+    for i in range(5, 10):
+        l2.append(Value(i))
+    l1 += l2
+    return [v.value for v in l1]
+
+def test_mul():
+    """
+    >>> test_mul()
+    [0, 1, 0, 1, 0, 1]
+    """
+    l1 = cyplist[Value]()
+    for i in range(2):
+        l1.append(Value(i))
+    l = l1 * 3
+    return [v.value for v in l]
+
+def test_imul():
+    """
+    >>> test_imul()
+    [0, 1, 0, 1, 0, 1]
+    """
+    l = cyplist[Value]()
+    for i in range(2):
+        l.append(Value(i))
+    l *= 3
+    return [v.value for v in l]
+
 def test_getitem_out_of_range():
     """
     >>> test_getitem_out_of_range()
@@ -337,3 +387,41 @@ def test_iterator_refcount():
         return 0
 
     return 1
+
+def test_concatenation_refcount():
+    """
+    >>> test_concatenation_refcount()
+    1
+    """
+    value = Value(1)
+    l1 = cyplist[Value]()
+
+    if Cy_GETREF(value) != 2:
+        return 0
+
+    l1.append(value)
+    if Cy_GETREF(value) != 3:
+        return 0
+
+    l2 = cyplist[Value]()
+    l2.append(value)
+    if Cy_GETREF(value) != 4:
+        return 0
+
+    l3 = l1 + l2
+    if Cy_GETREF(value) != 6:
+        return 0
+
+    l3 += l1
+    if Cy_GETREF(value) != 7:
+        return 0
+
+    l4 = l3 * 3
+    if Cy_GETREF(value) != 16:
+        return 0
+
+    l4 *= 2
+    if Cy_GETREF(value) != 25:
+        return 0
+
+    return 1