Changed minus operator to plus and unary minus.

All unit tests are converted to the new tree representation.

src/parser.py

@@ -274,15 +274,18 @@ class Parser(BisonParser):
     def on_binary(self, target, option, names, values):
         """
         binary : exp PLUS exp
-               | exp MINUS exp
                | exp TIMES exp
                | exp DIVIDE exp
                | exp POW exp
+               | exp MINUS exp
         """
 
-        if 0 <= option < 5:  # rule: exp PLUS exp
+        if 0 <= option < 4:  # rule: exp {PLUS,TIMES,DIVIDES,POW} exp
             return Node(values[1], values[0], values[2])
 
+        if option == 4:  # rule: exp MINUS exp
+            return Node('+', values[0], Node('-', values[2]))
+
         raise BisonSyntaxError('Unsupported option %d in target "%s".'
                                % (option, target))  # pragma: nocover
 

tests/parser.py

@@ -98,6 +98,28 @@ def run_expressions(base_class, expressions, fail=True, silent=False,
                 raise
 
 
+def apply_expressions(base_class, expressions, fail=True, silent=False,
+        **kwargs):
+    parser = ParserWrapper(base_class, **kwargs)
+
+    for exp, times, out in expressions:
+        res = None
+        try:
+            res = parser.run([exp] + list('@' * times))
+            assert res == out
+        except:  # pragma: nocover
+            if not silent:
+                print >>sys.stderr, 'error: %s gives %s, but expected: %s' \
+                                    % (exp, str(res), str(out))
+
+            if not silent and hasattr(res, 'nodes'):
+                print >>sys.stderr, 'result graph:'
+                print >>sys.stderr, generate_graph(res)
+                print >>sys.stderr, 'expected graph:'
+                print >>sys.stderr, generate_graph(out)
+
+            if fail:
+                raise
 def graph(parser, *exp, **kwargs):
     return generate_graph(ParserWrapper(parser, **kwargs).run(exp))
 

tests/test_b1_ch08.py

@@ -1,22 +1,23 @@
 import unittest
 
 from src.parser import Parser
-from src.node import ExpressionNode as N, ExpressionLeaf as L
-from tests.parser import run_expressions
+from src.node import ExpressionLeaf as L
+from tests.parser import run_expressions, apply_expressions
 
 
 class TestB1Ch08(unittest.TestCase):
 
-    def test_diagnostic_test(self):
+    def test_diagnostic_test_parser(self):
         run_expressions(Parser, [
-            ('6*5^2', N('*', L(6), N('^', L(5), L(2)))),
-            ('-5*(-3)^2', N('*', N('-', L(5)),
-                                 N('^', N('-', L(3)), L(2)))),
-            ('-5*(-3)^2', N('*', N('-', L(5)),
-                                 N('^', N('-', L(3)), L(2)))),
-            ('7p-3p', N('-', N('*', L(7), L('p')), N('*', L(3), L('p')))),
-            ('-5a*-6', N('*', N('*', N('-', L(5)), L('a')),
-                              N('-', L(6)))),
-            ('3a-8--5-2a', N('-', N('-', N('-', N('*', L(3), L('a')), L(8)),
-                                  N('-', L(5))), N('*', L(2), L('a')))),
+            ('6*5^2', L(6) * L(5) ** 2),
+            ('-5*(-3)^2', (-L(5)) * (-L(3)) ** 2),
+            ('7p-3p', L(7) * 'p' + -(L(3) * 'p')),
+            ('-5a*-6', (-L(5)) * 'a' * (-L(6))),
+            ('3a-8--5-2a', L(3) * 'a' + -L(8) + -(-L(5)) + -(L(2) * 'a')),
+            ])
+
+    def test_diagnostic_test_application(self):
+        apply_expressions(Parser, [
+            ('7p+2p', 1, (L(7) + 2) * 'p'),
+            #('7p-3p', 1, (L(7) - 3) * 'p'),
             ])

tests/test_b1_ch10.py

@@ -9,21 +9,12 @@ class TestB1Ch10(unittest.TestCase):
 
     def test_diagnostic_test(self):
         run_expressions(Parser, [
-            ('5(a-2b)', N('*', L(5), N('-', L('a'),
-                                       N('*', L(2), L('b'))))),
-            ('-(3a+6b)', N('-', N('+', N('*', L(3), L('a')),
-                                  N('*', L(6), L('b'))))),
-            ('18-(a-12)', N('-', L(18),
-                            N('-', L('a'), L(12)))),
+            ('5(a-2b)', L(5) * (L('a') + -(L(2) * 'b'))),
+            ('-(3a+6b)', -(L(3) * L('a') + L(6) * 'b')),
+            ('18-(a-12)', L(18) + -(L('a') + -L(12))),
             ('-p-q+5(p-q)-3q-2(p-q)',
-                N('-',
-                  N('-',
-                    N('+', N('-', N('-', L('p')), L('q')),
-                      N('*', L(5), N('-', L('p'), L('q')))),
-                    N('*', L(3), L('q'))
-                  ),
-                  N('*', L(2), N('-', L('p'), L('q')))
-                )
+                -L('p') + -L('q') + L(5) * (L('p') + -L('q')) + -(L(3) * 'q') \
+                + - (L(2) * (L('p') + -L('q')))
             ),
             ('(2+3/7)^4',
                 N('^', N('+', L(2), N('/', L(3), L(7))), L(4))

tests/test_calc.py

@@ -13,10 +13,10 @@ class TestCalc(unittest.TestCase):
 
     def test_basic_on_exp(self):
         expressions = [('4',   L(4)),
-                       ('3+4', N('+', L(3), L(4))),
-                       ('3-4', N('-', L(3), L(4))),
-                       ('3/4', N('/', L(3), L(4))),
-                       ('-4',  N('-', L(4))),
+                       ('3+4', L(3) + L(4)),
+                       ('3-4', L(3) + -L(4)),
+                       ('3/4', L(3) / L(4)),
+                       ('-4',  -L(4)),
                        ('3^4', N('^', L(3), L(4))),
                        ('(2)', L(2))]
 
@@ -83,7 +83,7 @@ class TestCalc(unittest.TestCase):
 
     def test_negation(self):
         run_expressions(Parser, [
-            ('-9', N('-', L(9))),
-            ('--9', N('-', N('-', L(9)))),
-            ('a--9', N('-', L('a'), N('-', L(9)))),
+            ('-9', -L(9)),
+            ('--9', --L(9)),
+            ('a--9', L('a') + -(-L(9))),
             ])