implement type checking list.contains()

closes #3.

doc/index.rst

@@ -990,6 +990,7 @@ API
 
    .. py:method:: path_like in l
    .. automethod:: __contains__
+   .. automethod:: contains
 
    .. py:method:: len(l)
    .. automethod:: __len__

src/sanest/sanest.py

@@ -948,6 +948,19 @@ def __contains__(self, value):
         """
         return clean_value(value) in self._data
 
+    def contains(self, value, *, type=None):
+        """
+        Check whether ``value`` is contained in this list.
+
+        This is the same as ``value in l`` but allows for a type check.
+
+        :param type: expected type
+        """
+        try:
+            return clean_value(value, type=type) in self._data
+        except InvalidValueError:
+            return False
+
     def index(self, value, start=0, stop=None, *, type=None):
         """
         Get the index of ``value``; like ``list.index()``.

test_sanest.py

@@ -1225,6 +1225,17 @@ def test_list_contains():
     assert str(excinfo.value) == "invalid value of type MyClass: <MyClass>"
 
 
+def test_list_contains_with_type():
+    l = sanest.list([1, 'a', {'c': 'd'}])
+    assert l.contains(1, type=int)
+    assert l.contains('a', type=str)
+    assert l.contains({'c': 'd'}, type=dict)
+    assert not l.contains(1, type=str)
+    assert not l.contains(2, type=str)
+    assert not l.contains({'x': 'y'}, type=dict)
+    assert not l.contains({'x': 'y'}, type=int)
+
+
 def test_list_iteration():
     l = sanest.list([
         {'a': 1},