non linearity

tests/test_nonlinearity.py

@@ -0,0 +1,13 @@
+from walsh.walsh import nonlinearity
+
+
+def test_nonlinearity_linear_function():
+    assert nonlinearity("x1 XOR x2") == 0
+
+
+def test_nonlinearity_or():
+    assert nonlinearity("x1 OR x2") == 1
+
+
+def test_nonlinearity_majority():
+    assert nonlinearity("x1*x2 XOR x1*x3 XOR x2*x3") == 2