Switched precedence of power and functions, and added some unit tests for it (corresponding to WolframAlpha's output).

src/parser.py

@@ -63,8 +63,8 @@ class Parser(BisonParser):
         ('left', ('TIMES', 'DIVIDE')),
         ('left', ('EQ', )),
         ('left', ('NEG', )),
-        ('right', ('SIN', 'COS', 'TAN', 'SOLVE', 'INT', 'SQRT')),
         ('right', ('POW', )),
+        ('right', ('SIN', 'COS', 'TAN', 'SOLVE', 'INT', 'SQRT')),
         )
 
     interactive = 0

tests/test_parser.py

@@ -4,6 +4,8 @@ import unittest
 from src.parser import Parser
 from src.node import ExpressionNode as Node, ExpressionLeaf as Leaf
 from tests.parser import ParserWrapper, run_expressions, line, graph
+from tests.rulestestcase import tree
+from src.rules.goniometry import sin, cos
 
 
 class TestParser(unittest.TestCase):
@@ -15,11 +17,11 @@ class TestParser(unittest.TestCase):
         run_expressions(Parser, [('a', Leaf('a'))])
 
     def test_graph(self):
-        assert graph(Parser, '4a') == ("""
+        self.assertEqual(graph(Parser, '4a'), ("""
          *
         ╭┴╮
         4 a
-        """).replace('\n        ', '\n')[1:-1]
+        """).replace('\n        ', '\n')[1:-1])
 
     def test_line(self):
         self.assertEqual(line(Parser, '4-a'), '4 - a')
@@ -35,3 +37,14 @@ class TestParser(unittest.TestCase):
         self.assertNotEqual(possibilities2, [])
 
         self.assertNotEqual(possibilities1, possibilities2)
+
+    def test_functions(self):
+        root, x = tree('sin x, x')
+
+        self.assertEqual(root, sin(x))
+        self.assertEqual(tree('sin x ^ 2'), sin(x) ** 2)
+        self.assertEqual(tree('sin(x) ^ 2'), sin(x) ** 2)
+        self.assertEqual(tree('sin (x) ^ 2'), sin(x) ** 2)
+        self.assertEqual(tree('sin(x ^ 2)'), sin(x ** 2))
+        self.assertEqual(tree('sin cos x'), sin(cos(x)))
+        self.assertEqual(tree('sin cos x ^ 2'), sin(cos(x)) ** 2)