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comparison python/testpyy.py @ 185:51a6440d6398

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Fixed LR(1) parser
author Windel Bouwman
date Fri, 24 May 2013 20:45:03 +0200
parents fe2b72381a83
children 6b2bec5653f1
comparison
equal deleted inserted replaced
184:fe2b72381a83 185:51a6440d6398
22 # 3. build parser: 22 # 3. build parser:
23 p = g.genParser() 23 p = g.genParser()
24 # 4. feed input: 24 # 4. feed input:
25 p.parse(tokens) 25 p.parse(tokens)
26 26
27 class testExpressionGrammar(unittest.TestCase):
28 def setUp(self):
29 g = Grammar(['EOF', 'identifier', '(', ')', '+', '*', 'num'])
30 g.add_production('input', ['expression'])
31 g.add_production('expression', ['term'])
32 g.add_production('expression', ['expression', '+', 'term'])
33 g.add_production('term', ['factor'])
34 g.add_production('term', ['term', '*', 'factor'])
35 g.add_production('factor', ['(', 'expression', ')'])
36 g.add_production('factor', ['identifier'])
37 g.add_production('factor', ['num'])
38 g.start_symbol = 'input'
39 self.g = g
40
41 def testFirstSimpleGrammar(self):
42 # 1. define a simple grammar:
43 first = self.g.calcFirstSets()
44 self.assertEqual(first['input'], {'identifier', '(', 'num'})
45 self.assertEqual(first['term'], {'identifier', '(', 'num'})
46
47 def testCanonical(self):
48 s0 = self.g.initialItemSet()
49 s, gt = self.g.genCanonicalSet(s0)
50 # Must result in 12 sets:
51 self.assertEqual(len(s), 24)
52
27 class testPG(unittest.TestCase): 53 class testPG(unittest.TestCase):
28 """ Tests several parts of the parser generator """ 54 """ Tests several parts of the parser generator """
29 def setUp(self): 55 def setUp(self):
30 g = Grammar(['(', ')']) 56 g = Grammar(['(', ')'])
31 g.add_production('goal', ['list']) 57 g.add_production('goal', ['list'])
32 g.add_production('list', ['list', 'pair']) 58 g.add_production('list', ['list', 'pair'])
33 g.add_production('list', ['pair']) 59 g.add_production('list', ['pair'])
34 g.add_production('pair', ['(', 'pair', ')']) 60 g.add_production('pair', ['(', 'pair', ')'])
35 g.add_production('pair', ['(', ')']) 61 g.add_production('pair', ['(', ')'])
36 g.start_symbol = 'goal' 62 g.start_symbol = 'goal'
37 g.first = g.calcFirstSets()
38 self.g = g 63 self.g = g
39 64
40 def testFirstSet(self): 65 def testFirstSet(self):
41 for a in ['(', ')', EOF, 'EPS']: 66 for a in ['(', ')', EOF, 'EPS']:
42 self.assertEqual(self.g.first[a], {a}) 67 self.assertEqual(self.g.first[a], {a})
58 self.assertIn(Item(p4, 0, '('), s0) 83 self.assertIn(Item(p4, 0, '('), s0)
59 84
60 def testCanonical(self): 85 def testCanonical(self):
61 s0 = self.g.initialItemSet() 86 s0 = self.g.initialItemSet()
62 s, gt = self.g.genCanonicalSet(s0) 87 s, gt = self.g.genCanonicalSet(s0)
63 pprint.pprint(s)
64 # Must result in 12 sets: 88 # Must result in 12 sets:
65 self.assertEqual(len(s), 12) 89 self.assertEqual(len(s), 12)
66 90
67 def testClosure(self): 91 def testClosure(self):
68 p0, p1, p2, p3, p4 = self.g.productions 92 p0, p1, p2, p3, p4 = self.g.productions
69 s0 = set() 93 s0 = set()
70 for p in self.g.productionsForName(self.g.start_symbol): 94 s0.add(Item(p0, 0, EOF))
71 s0.add(Item(p, 0, EOF))
72 self.assertEqual(len(s0), 1) # 1 rule 95 self.assertEqual(len(s0), 1) # 1 rule
73 self.assertIn(Item(p0, 0, EOF), s0) 96 self.assertIn(Item(p0, 0, EOF), s0)
74 97
75 # Invoke closure on set: 98 # Invoke closure on set:
76 s0 = self.g.closure(s0) 99 s0 = self.g.closure(s0)
83 self.assertIn(Item(p3, 0, '('), s0) 106 self.assertIn(Item(p3, 0, '('), s0)
84 self.assertIn(Item(p4, 0, EOF), s0) 107 self.assertIn(Item(p4, 0, EOF), s0)
85 self.assertIn(Item(p4, 0, '('), s0) 108 self.assertIn(Item(p4, 0, '('), s0)
86 109
87 def testParser(self): 110 def testParser(self):
88 tokens = ['(', '(', ')', '(', ')', ')', 'EOF'] 111 tokens = ['(', '(', ')', ')', '(', ')', EOF]
89 # 3. build parser: 112 # 3. build parser:
90 p = self.g.genParser() 113 p = self.g.genParser()
114 self.assertEqual(len(p.goto_table), 5)
115 self.assertEqual(len(p.action_table), 19)
116
91 # 4. feed input: 117 # 4. feed input:
92 p.parse(tokens) 118 p.parse(tokens)
93 119
94 if __name__ == '__main__': 120 if __name__ == '__main__':
95 unittest.main() 121 unittest.main()