Added some more unit tests for line generator.

tests/test_line.py

@@ -100,21 +100,25 @@ class TestLine(unittest.TestCase):
         a, b, c, l2 = L('a'), L('b'), L('c'), L(2)
         mul = N('*', a, b)
         self.assertEquals(generate_line(mul), 'ab')
-
         mul = N('*', mul, c)
         self.assertEquals(generate_line(mul), 'abc')
+        mul = N('*', N('*', a, l2), b)
+        self.assertEquals(generate_line(mul), 'a * 2b')
 
         mul = N('*', a, N('-', b, c))
         self.assertEquals(generate_line(mul), 'a(b - c)')
+        mul = N('*', l2, N('-', b, c))
+        self.assertEquals(generate_line(mul), '2(b - c)')
 
         mul = N('*', N('+', a, b), c)
         self.assertEquals(generate_line(mul), '(a + b)c')
+        mul = N('*', N('+', a, b), l2)
+        self.assertEquals(generate_line(mul), '(a + b) * 2')
 
         mul = N('*', N('+', a, b), N('+', c, l2))
         self.assertEquals(generate_line(mul), '(a + b)(c + 2)')
 
         mul = N('*', l2, a)
         self.assertEquals(generate_line(mul), '2a')
-
         mul = N('*', a, l2)
         self.assertEquals(generate_line(mul), 'a * 2')